Proposal for a Directive of the European Parliament and of the Council amending Directive 97/68/EC on the approximation of the laws of the Member States relating to measures against the emission of gaseous and particulate pollutants from internal combustion engines to be installed in non-road mobile machinery
Date: 2002-12-27
Institutions: European Commission
Subjects: atmospheric pollutant, engine, environmental standard, pollution, reduction of gas emissions

COMMISSION OF THE EUROPEAN COMMUNITIES

Brussels, 27.12.2002
COM(2002) 765 final

2002/0304 (COD)

Proposal for a

DIRECTIVE OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL

amending Directive 97/68/EC on the approximation of the laws of the Member States
relating to measures against the emission of gaseous and particulate pollutants from
internal combustion engines to be installed in non-road mobile machinery

(presented by the Commission)

EXPLANATORY MEMORANDUM

1.

OBJECTIVE OF THE PROPOSAL

Requirements concerning emissions of air pollutants from compression ignition (CI) engines
intended for use in non-road mobile machinery and with an engine power of 18-560 kW are
covered  by  Directive  97/68/EC.  The  Directive  includes  two  stages  of  emission  standards.
Stage I standards have already entered into force for all power bands and Stage II standards
will  enter  into  force  between  31  December  2000  and  31  December  2003  depending  on  the
power band.  In December 2000,  the  Commission,  in  accordance  with  recital  (5)  of  the  said
Directive,  presented  a  proposal  to  include  small  (19  kW  or  below)  spark-ignition  (petrol)
engines within its scope. This proposal was voted on by the European Parliament for second
reading in July 2002 and the Council has accepted the result of that voting.

Furthermore, Article 19 of the Directive provides for  a  tightening of the  emission standards
for  compression  ignition  engines.  The  Commission  should  submit  a  proposal  for  a  further
reduction  in  limit  values  based  on  the  techniques  generally  available  for  controlling  air-
polluting emissions and the air quality situation.

2.

BACKGROUND

2.1.

Air quality situation

2.1.1. General

The Auto-oil Programme (COM (2000) 626 final) concluded that, although air quality within
the  Community  has  improved  and  would  further  improve  as  the  result  of  action  already
decided  upon,  environmental  air  quality  problems  would  still  remain.  It  mentioned  in
particular  the  need  to  address  ozone  formation  (the  emission  of  nitrogen  oxides,  NOx,  and
volatile organic compounds,  VOCs,)  and particulate  emissions.  In addition, local air  quality
problems in the form of high NO2 levels would remain in some cities.

2.1.2.

Emissions from CI engines in non-road mobile machinery (NRMM)

In relation to the remaining air quality problems, as presented in the Auto-Oil II Programme,
the pollutants of importance from CI engines are NOx and particulate matter (PM). Emissions
of VOCs, the other precursor of ozone, are generally low from these engines.

With a few exemptions, non-road mobile machinery is not registered. Furthermore, the actual
uses of the different types of NRMM vary considerably. It is therefore difficult to estimate the
actual emissions from this equipment with any degree of accuracy.

At Community level  a rather  comprehensive inventory  was made in 1994 as a  basis  for the
implementation  of  Directive  97/68/EC.  The  study  did  of  course  include  some  uncertainties,
and is now some years old, but it does nevertheless give a rough estimate of emissions from
non-road  mobile  machinery  –  including  tractors.  According  to  this  inventory,  emissions
before the introduction of Stage I of Directive 97/68/EC were as follows:

2

Engines

All  CI  engines  covered  by
and
Directive 
agricultural  & 
forestry
tractors

97/68/EC 

NOx (kt)

1,630

PM (kt)

190

The implementation of Stages I and II of the current legislation has reduced and will further
reduce  those  emissions.  It  is  reasonable  to  assume  that  compared  with  a  “non-regulated”
engine, a Stage II engine emits around 40% less NOx and 60% less PM. To a certain extent
this  reduction  has  been  counteracted  by  the  increased  number  of  engines.  Based  on  that
inventory,  overall  emissions  from  non-road  mobile  machinery  with  engines  of  19  kW  or
above, including tractors, will be as shown in the table below once  all current engines have
been replaced by Stage II engines.

To  give  a  rough  idea  of  the  overall  level  of  emissions  the  data  from  the  final  Auto-Oil  II
report has been incorporated into the table below

NOx (kt)

1,000

Sources

97/68/EC 

All  CI  engines  covered  by
and
Directive 
agricultural  & 
forestry
tractors  -  estimate  for  2020
(all  engines  meeting  Stage  II
limit values)

Overall emissions 2020

6,015

(AO II report)

Emissions 
transport 2020.

(AO II report)

from 

road

985

(1) Tailpipe emissions only

2.1.3. Conclusions

PM (kt)

80

1,538

83 (1)

It can be concluded that there is a need for further action to tackle air quality problems in the
future.  This  was  mentioned  in  Article  19  of  the  current  Directive  97/68/EC  as  one  of  the
prerequisites for Stage III. It can further be concluded that emissions from non-road mobile
machinery,  even  allowing  for  the  uncertainty  of  the  emission  inventories,  will  significantly
add to those air quality problems.

2.2.

Globally available technology

The number of engines produced for non-road mobile machinery is much lower than for on-
road applications.  A  global market  has  therefore  been  developed  for  these  products.  This  is

3

the reason for mentioning the availability of abatement technology on a global basis in Article
19 of the current Directive 97/68/EC.

Primarily because of higher production volume, the development of  advanced technology to
reduce pollutant emissions from CI engines has generally taken place within the field of on-
the  necessary
road  applications.  These 
modifications,  in  the  non-road  sector  some  years  later.  So  it  makes  sense  when  estimating
future  availability  of  advanced  abatement  technology  to  use  legislation  and  technical
development in the on-road sector as a starting point. When doing this it needs to be borne in
mind that non-road equipment works in a different environment and that on-road technologies
cannot always be directly transferred to all kinds of non-road applications.

technical  solutions  are 

then  applied,  with 

2.2.1. On-road legislation in Europe

As a result of the Auto-Oil Programme, the emission standards for on-road vehicles are to be
tightened in stages. In 2005 Euro IV standards will be implemented with very low limit values
for  particulate  emissions.  When  deciding  on  this  legislation,  it  was  anticipated  that
manufacturers  would  need  to  use  particulate  traps  or  technology  with  corresponding
performance to meet those limit values.

For heavy-duty vehicles, a further tightening of the NOx limit values will be introduced from
2008, although subject to a technical review clause. To meet these limit values manufacturers
need to use some kind of after-treatment device.

2.2.2. On-road legislation in the US

In December 2000, the US administration decided on a next set of limit values for heavy-duty
vehicles. Those limit  values will  enter  into  force  starting  in  2007.  For  particulate  emissions
the  limit  value  is  more  or  less  the  same  as  the  European  Euro  IV/V  value  and  for  NOx
emissions the limit value is in principle a sixth of the Euro V limit value. Thus - to meet those
US-standards  -  manufacturers  have  to  use  after-treatment  devices  for  both  PM  and  NOx
emissions.

2.2.3. On-road legislation in Japan

Emission  legislation  for  CI  engines  on  heavy-duty  vehicles  has  traditionally  been  less
stringent in Japan than the corresponding legislation in the US and the EU. However, because
of the deterioration in air quality, Japan has decided to implement far-reaching legislation in
stages to  reduce  the  emission  of  NOx  and  PM.  A  first  stage,  which  is  in  the  same  order  of
magnitude  as  the  Euro  IV  standards,  will  be  implemented  in  2005  and  a  further  stage  is
planned for the future.

2.2.4. Conclusions

It can be concluded that, in principle, technology to further limit the emissions of air pollution
from  CI  engines  is  available  or  will  be  available  on  the  global  market  within  3  to  5  years
(prerequisite 2 in Article 19). However, since this technology has been developed for on-road
applications, it will in many cases have to be modified for non-road applications. Indeed, for
certain  applications  it  might  ultimately  be  technically  impossible  or  very  expensive  to  use.
This issue will be discussed later in this explanatory memorandum.

4

3.

ISSUES OF IMPORTANCE FOR THE IMPLEMENTATION OF STAGE III

3.1.

Global alignment

As  mentioned  previously,  engines  for  use  in  NRMM  are  to  a  large  extent  produced  for  a
global market. Production volumes for different engine types are low and development costs
would  therefore  be  difficult  to  bear  if  different  regional  emission  requirements  were
introduced.

Consequently,  global  alignment  was  a  high  priority  when  the  current  legislation  was
developed. It also succeeded to the extent that the current emission requirements of Directive
97/68/EC are similar to  those  in Japanese and  US  legislation,  making  it  possible  for  engine
manufacturers to offer one and the same concept on those markets.

Concerning future legislation, the USA has already decided to introduce Tier III standards for
engines from 37 kW to 560 kW. Those standards, which cover only gaseous emissions, will
be  implemented  between  2006  and  2008  depending  on  the  power  band  of  the  engines.  A
future Tier IV is being discussed by the US administration and according to information from
the  EPA  (the  US  Environmental  Protection  Agency)  a  notice  of  proposed  rulemaking
(NPRM) is expected at the beginning of 2003. The EPA has also indicated that it intends to
base this proposal on what has already been decided for on-road vehicles, i.e. the use of after-
treatment equipment.

Furthermore  emission  limit  values  for  the  power  band  19-37  kW  going  beyond  the  current
Stage II limits in Directive 97/68/EC are included in the current US legislation.

Japan has so far taken no decision on further tightening of the emission standards beyond the
current  EU  Stage  II  standards,  but  it  is  participating  in  the  international  discussions  now
taking place between the authorities and the industry.

3.1.1. Conclusions

Global alignment  is a high priority issue as  regards  future  emission  standards. Accordingly,
the process of amending Directive 97/68/EC on Stage III limit values has been discussed very
closely with  industry  and  authorities  in  the  USA  and  Japan.  The  aim  has  been  to  achieve  a
win-win situation where the industry can operate with one and the same set of concepts on a
global market and by so doing save money that can be used in part to achieve a high level of
environmental protection.

3.2.

Scope of the Directive

3.2.1.

Engine power band

The current Directive 97/68/EC covers CI engines of 18 kW to 560 kW. The corresponding
US legislation covers the power band 19-560 kW. In practice it does not matter if the power
band starts at 19 or 18 kW but for the sake of future alignment the Directive 97/68/EC should
use 19 kW instead of 18 kW in any future requirements.

In the USA engines below 19 kW and above 560 kW are also covered by legislation and to
achieve further alignment it could be argued that limit values for these engines should also be
included in Directive 97/68/EC. However, the inventory referred to in point 1.1.2 above does
not  show  that  these  engines  notably  contribute  to  the  overall  emissions  in  the  EU.  It  is
therefore  currently  difficult  to  justify  devising  legislation  for  this  category  of  CI  engines.

5

However, to further align the legislation, this should be studied further and be included as a
part of the technical review discussed below in paragraph 3.9.

Moreover,  under  an  amendment  recently  decided  upon  by  the  Council  and  the  European
Parliament, the Directive will cover small petrol engines (19 kW or below).

3.2.2.

Exempted applications

In  addition  to  limitations  imposed  by  engine  power,  certain  applications  are  currently
exempted from the scope of the Directive, namely:

the propulsion of:

-

-

and

applications in:

vehicles (on-road vehicles) as defined by Directive 70/156/EEC, and by
Directive 92/61/EEC,

agricultural tractors as defined by Directive 74/150/EEC

-

-

-

-

-

ships

railway locomotives

aircrafts

generating sets

recreational vehicles.

For  on-road  vehicles  existing  standards,  and  those  adopted  for  the  future,  are  tighter  than
those for NRMM and there is no reason to include those within the scope of Directive 97/68.

Tractors  are  covered  by  another  Directive  -  Directive  2000/25/EC  –  with  requirements
basically  identical  to  those  in  Directive  97/68/EC  (but  with  some  differences  as  regards
implementation dates). The tractor Directive states that as soon as the provisions referred to in
Article 19 of Directive 97/68/EC are adopted, the limit values and implementation dates are to
be aligned without  delay.  Consequently,  as  soon  as  a  formal  decision  on  the  amendment  to
Directive 97/68/EC has been taken, the Commission will forward a proposal on the same limit
values  and  entry  into  force  dates  to  be  implemented  into  Directive  2000/25/EC  using  the
committee procedure.

The  abovementioned  amendment  on  spark  ignition  engines  also  included  limit  values  for
generating sets and other constant speed engines – CI engines as well as SI engines - thereby
removing the exemption for generating sets.

Recreational  vehicles  are  of  interest  chiefly  as  regards  petrol  engines  only  and  will  not  be
discussed in this proposed amendment on diesel engines.

Railway locomotives, defined as locomotives that are “not designed to carry any passengers or
freight by themselves”, are covered by separate legislation in the USA. The engines they use

6

normally  are  more  powerful  than  560  kW.  Other  railway  applications,  e.g.  engines  in  rail-
cars, are covered by the normal NRMM legislation.

The current Directive 97/68/EC contains no definition of “locomotives”. For better alignment,
we should use the same definition as in US legislation. This would then cover “small” engines
used for railway applications.

Furthermore,  the  Commission  addressed  this  issue  in  its  communication  “Towards  an
integrated  European  railway  area”  (COM  (2002)  18  final).  Concerning  air  pollution,  it
declared its intention to include “light-duty diesel train engines ” into the revision of Directive
97/68/EC  and  to  develop  technical  interoperability  specifications  for  heavy-duty  diesel
engines.

It  has  been  argued  that  emission  standards  for  railway  applications  should  be  based  on  a
separate test cycle, since of  course the driving pattern of  a  railway vehicle  is different  from
that of an excavator or an agricultural tractor. This is especially so for genuine locomotives.
However, for reasons discussed under “test procedure” below, it is proposed not to include a
separate test procedure in Directive 97/68/EC.

Ships have recently  been shown  to  be  a  major  contributor  to  overall  emissions  of  NOx  and
particulates. This is true in particular of sea-going ships but also vessels on inland waterways
are contributers.

In  its  White  Paper  on  a  common  transport  policy  the  Commission  pointed  out  not  only
railways  but  also  inland  waterways  as  environmentally  friendly  modes  of  transport.  To
confirm  this  role  vessels  used  on  inland  waterways  have  to  improve  their  environmental
performance.

On  an  international  level  the  International  Maritime  Organisation  (IMO)  has  developed
regulations  covering  emissions  of  NOx  from  ships  (MARPOL,  Annex  VI).  However  this
Annex has still not entered into force due to the lack of necessary ratification. Furthermore it
does not address the emissions of particulates, which is an issue of very high priority.

Engine manufacturers have expressed their favour of implementing the limit values (and ISO
test  procedure)  used  in  the  USA  for  this  kind  of  engines.  These  limit  values  are  ambitious
from an environmental point of view and will meet the overall target of alignment and could
therefore also be used in the EU legislation.

The  strategy  on  how  to  address  the  emissions  from  sea-going  ships  will  be  addressed  in  a
separate Communication from the Commission.

Recreational Craft are covered by another Directive – Directive 94/25/EC. The Commission
proposed  in  October  2000  an  amendment  to  this  Directive  to  include  exhaust  and  sound
emission limits for engines to be used in recreational craft (COM(2000)639). The Council’s
common position on this amendment, adopted on 22 April 2002, contains a review clause in
its Article 2. This clause provides that the Commission shall submit by 31 December 2005 a
report on the possibilities of further reducing  emissions from recreational craft  and personal
watercraft and, in the light of this report, submit by 31 December 2006 appropriate proposals
to  the  European  Parliament  and  the  Council  on  more  stringent  requirements  and  emission
values. Therefore there is no reason to include recreational craft engines within the scope of
Directive 97/68.

7

3.2.3. Conclusions

To  achieve  further  alignment  with  US  legislation,  the  current  lowest  power  limit  of  18  kW
should  be  changed  to  19  kW.  Engines  below  19  kW  and  above  560  kW  should,  for  the
moment being, remain outside the scope of the Directive.

For agricultural and forestry tractors, implementation dates and limit values are to be aligned
through the Commission proposal on an amendment to Directive 2000/25/EC, which is being
presented in parallel to this proposal.

A  clarification  of  definitions  should  be  inserted  in  order  to  cover  emissions  from  railway
applications, except for locomotives that “are not designed to carry any passengers or freight
by themselves” to align it with US legislation.

Vessels used on inland waterways should be included within the scope of Directive 97/68/EC.
Since  they  have  so  far  been  excluded  and  since  they  are  of  a  different  technical  nature,
separate emission limits and entry into force dates should apply.

3.3.

Test procedure

The  current  procedure  for  measuring  emissions  in  Directive  97/68/EC  is  based  on  a  steady
state  test  cycle,  the  ISO  8178-4  C1  8-mode  cycle.  Since  NRMM  covers  a  lot  of  different
applications with different  practical operations, it will be very difficult to cover  all  of  those
with  one  test  cycle.  Consequently,  the  current  test  cycle  does  not  represent  all  the  actual
operating  conditions  for  NRMM.  Furthermore,  it  does  not  include  some  of  the  modes  of
operation  which  generate  the  most  air  pollution.  However,  with  the  new  stringent  emission
levels it is considered a good compromise.

When tightening emission limits, it becomes more important to have a test procedure covering
the  most  important  modes  of  operation  in  order  to  avoid  any  discrepancy  between  real-life
emissions  and  laboratory  measurements.  Particulate  matter  (PM)  in  particular  is  far  more
prevalent when operating under "transient conditions". This was confirmed when developing
the  current  EU  legislation  on  emissions  from  on-road  vehicles,  which  resulted  in  the
introduction of a transient test procedure.

Most  non-road  engines  are  used  for  applications  that  are  largely  transient  in  nature.  Even
equipment  such  as  pumps  and  generators,  which  operate  mostly  at  constant  speeds,  may
depart  from  steady-state  operation  because  of  variations  in  engine  load  over  time.  Through
broad co-operation between the authorities and industry in the USA, Japan and Europe efforts
have therefore been made to develop a new test cycle which will better reflect this.

This co-operation has resulted in a new transient test cycle that will meet those requirements.
The test cycle has been developed so that it can be run on eddy-current dynamometers with
significant  cost  saving  (between  a  third  and  a  quarter  of  the  usual  cost)  over  conventional
equipment  (AC  dyno  or  DC  dyno)  used  for  transient  tests  without  compromising  on
environmental objectives.

Even higher cost saving (a fifth of usual cost or less) can be obtained if the transient test is
carried out using the partial flow dilution systems already used for the steady-state procedure,
instead  of  using  the  conventional  CVS  (Constant  Volume  Sampling)  facility.  The  work,
performed  under  ISO/FDIS  16183  “Heavy  duty  engines  –  Measurement  of  gaseous  and
particulate  exhaust  emissions  under  transient  test  conditions  –  Raw  exhaust  gas  and  partial

8

flow dilution systems”, has now been concluded and, according to the EC, the procedure can
be transferred from on-road to non-road engines.

This  new  test  procedure  should  be  mandatory  for  measuring  PM  emissions  as  soon  as  the
Stage  III  B  values  enter  into  force.  For  gaseous  pollutants  the  manufacturer  could  use  the
current test procedure, but in order to avoid two tests, manufacturers will most likely use the
transient test procedure for gaseous pollutants too, once the Stage III B values apply.

The attention has been drawn to the fact that locomotives have different patterns of operation
compared to other NRMM applications, and thus a separate test procedure ought to be used.
Indeed, a separate test procedure already exists - the ISO 8178-4 steady-state test cycle type F
“Rail traction”. This type F test cycle appears to accurately reflect the operational behaviour
of the old power-train system used on the railways.

However it is important to bear in mind the purpose of the emission legislation – to reduce the
environmental and health impact. In this respect it is rather the local emissions, which occur
around railway stations in urban areas, than the contribution to the overall emissions that are
of importance for railways. Those emissions occur during accelerations and under heavy load
of the engines whereas emissions during constant speed, mostly in rural areas, are very low.
Using  a  separate  test  procedure  would  allow  an  averaging  of  the  emissions  and  thus  not
address the real environmental problems.

Nevertheless further studies should be carried out and if appropriate modify the test procedure
before stringent particulate emission limit values enter into force. This can be covered in the
technical review discussed below in paragraph 3.9.

It should also  be  noted that in the  corresponding US legislation  a  separate  test  procedure  is
only  used  for  genuine  locomotives,  which  anyhow  will  not  be  covered  by  the  scope  of
Directive 97/68/EC.

3.3.1. Conclusions

The  future  Stage  IIIB  standards  on  particulate  matter  should  be  based  on  a  new  dedicated
transient  test  procedure  to  better  reflect  actual  operating  conditions,  and  especially  to
represent real emissions of particulates and to ensure that emissions reduction technology is
developed to address those operating conditions.

For  the  measurement  of  gaseous  emissions,  manufacturers  should  have  the  option  of  using
either the new transient test cycle or the current steady-state test procedure.

 Different test procedures should be used for all variable speed engines except those for inland
waterways,  though  specific  consideration  should  be  given  to  engines  for  constant  speed
applications  and  railway  applications  in  the  technical  review  discussed  below  in  paragraph
3.9.  For  engines  intended  to  be  used  for  propulsion  of  inland  waterway  vessels,  the
internationally  accepted  test  procedures  according  to  ISO  8178-4,  test  cycles  E2  and  E3
should be applied.

The current possibility for manufacturers to choose between full flow systems or partial flow
systems should remain.

9

3.4.

Limit values and implementation dates for Stage III

3.4.1.

Limit values

3.4.1.1. Limit values for power bands 37-560 kW

Although in theory a large number of possible limit values can be chosen for Stage III, these
will in practice be limited by the number of technological steps that can be implemented.

In  principle  we  are  talking  about  two  different  levels  of  intervention:  engine  modifications
only,  and  the  use  of  after-treatment  equipment.  These  "technical  levels"  must  of  course  be
converted into limit values, allowing manufacturers to choose the specific technical solutions
necessary to meet the standards.

The possible scenarios for the Stage III level are basically the following:

Scenario

Environmental
improvements

Technology
available
today?

Technology
available
2010?

Fuel
requirements

Comments

(*)

1.

2.

3.

4.

NOx: - 30-40%

Yes

Yes

S: 1000 ppm

PM: - 0-10%

NOx: - 30-40%

Yes

Yes

S: 350 ppm

PM: - 30-40%

NOx: - 30-40%

No

Yes

S: 10-50 ppm

PM: - 80-90%

NOx: -70-80%

No

Yes

S: 10-50 ppm

PM: - 80-90%

(*) Environmental improvements as emission reductions [%] with respect to Stage II engines.

Scenario  1  corresponds  to  the  Tier  III  already  decided  upon  by  the  USA.  It  can  be  met  by
engine modifications, it could be implemented with a short lead time and it would meet the
industry's  wish  for  alignment.  It  would  not  however  address  the  issue  of  emissions  of  PM,
which was highlighted in the Auto-Oil II Communication as a high-priority form of pollution
and which has been addressed as an important issue by several Member States. It is therefore
questionable whether a proposal based on this scenario would adequately meet the identified
environmental  needs.  In  the  long  term  this  scenario  cannot  achieve  global  alignment  since
additional PM limit values will be implemented in the USA. Under this scenario there is no
need for further restrictions on fuel sulphur level, beyond those already decided (1000 ppm).

Scenario 2 includes limit values for PM. These can be met by engine modifications (including
the use of cooled EGR) in line with the on-road Euro 3 technology.  It should be noted that,
compared  with  Stage  II  emissions,  the  main  reduction  in  PM  is  due  to  the  lower  sulphur
content  of  the  fuel  even  though  engine  modifications  are  expected  to  reduce  emissions  still

10

further  by  another  10%.  To  meet  the  requirements  of  this  scenario  the  use  of  fuels  with  a
lower  sulphur  content  (max.  350  ppm)  must  be  made  mandatory  by  amending  Directive
98/70/EC. This scenario needs a longer lead time than Scenario 1 and will not achieve global
alignment.

Scenario  3  is  based  on  the  assumption  that  after-treatment  equipment  is  used  to  reduce
emissions of particulates. This technology is already available in the road vehicle sector and,
given a reasonable lead time, should be available for most applications in the non-road sector
too. Reduction of NOx is in line with Scenario 2. A maximum sulphur content of 50 ppm is
required. This scenario could lead to global alignment.

Scenario  4  differs  from  Scenario  3  to  the  extent  that  after-treatment  equipment  is  also
expected to reduce NOx. In the USA, the EPA has unofficially announced that in the future
they  would  like  to  move  towards  something  like  Scenario  4.  However,  they  do  agree  that
uncertainty about the technology is greater for  NOx  after-treatment technology  than  for  PM
traps within the NRMM sector and therefore expect to introduce tighter limit values later for
NOx than for PM. As for Scenario 3, a maximum sulphur content of 50 ppm is required. This
scenario could lead to global alignment.

It is obvious that the availability and feasibility of after-treatment equipment will be of great
importance when  deciding  on Stage 3 limit  values.  Auto-oil  II  considered  particulates to  be
one  remaining  air  quality  problem  for  the  future.  Many  reports  have  identified  small
(ultrafine) particles as perhaps the most important issue affecting health. As explained above,
basic after-treatment technology (PM traps) is already available for the on-road sector and to a
certain extent also for the non-road sector. Tests also show that technology developed for on-
road vehicles  can generally also be used for  certain applications in  the non-road sector, and
given enough lead time possibly for most other applications.

It  is  of  course  true  that  the  environment  in  which  NRMM  machinery  operates  tends  to  be
different from the on-road sector. For instance, the exhaust temperature might be too low to
use  PM  traps  with  passive  regeneration.  This  could  also  apply  to  city  buses,  which  are  not
exempt  from  the  Euro  IV  standards.  Nevertheless,  it  might  ultimately  prove  that  the  use  of
PM traps or technology with similar performance is not possible for some applications even if
industry is allowed a long lead time. To address this uncertainty, a technical review could be
carried out before the entry into force dates to determine whether there will have to be certain
exemptions  from  the  standards.  This  solution  was  used  when  introducing  Euro  V  standards
for Heavy Duty Vehicles in Directive 1999/96/EC.

Bilateral discussions with the EPA have clearly indicated that its intention is to base the next
stage  of  US  legislation  in  this  field  on  the  use  of  after-treatment  equipment  originally
developed  for  the  road  sector.  It  seems  that  the  EPA  plans  to  implement  these  stringent
requirements for PMs first, and then for NOx some years later.

As  regards,  PMs  there  are  no  basic  differences  between  the  situation  in  the  USA  and  the
situation in the EU. There will be the same need for low-sulphur fuel, and the technology is
global and can be applied in the same way. Thus a Stage III standard for particulate emissions
equal to the corresponding Tier IV standard in the USA seems feasible.

For NOx emissions, however, the current situation is a bit more complicated. For the on-road
sector, standards  have been  decided upon  in  the USA  and in  the  EU  that  will  require  after-
treatment equipment. The limit value in the EU legislation though is about eight times higher
than the US limit value.The EPA has declared quite categorically that it is in favour of NOx

11

absorbers as the technology to be used whilst manufacturers in Europe seem to favour the use
of SCR (Selective Catalytic Reduction), which needs a separate ammonium/urea distribution
system. For the  on-road  sector  the  choice  of  different  strategies  is  somewhat  less  important
since the market is not global as is the case for the non-road sector. For the non-road sector,
however,  the  current  strongly  global  approach  could  be  jeopardised  if  Europe  favours
technological development of SCR and the US opts for NOx absorbers.

Furthermore, in the EU the Euro V standards for NOx are subject to a technical review by the
Commission before the end of 2002. Even though this review will probably conclude that the
necessary  technology will be available for the on-road sector by 2008 (when Euro  V  enters
into  force),  the  Commission  cannot  be  expected  to  present  conclusions  on  the  use  of  this
technology in the non-road sector before that review is published. Neither can it be excluded
that the Euro V limit values will be tightened as a result of the technical review.

In addition, the Commission is currently studying the future air quality situation and the need
for action under the CAFE project (Clean Air For Europe). The result of this project will be
available  in  2004/2005  and  should  serve  as  input  for  a  subsequent  decision  on  a  possible
Stage IV limit value for NOx. This kind of consideration should be covered by the technical
review discussed below in paragraph 3.9.

3.4.1.2. Limit values for power band 19-37 kW.

US legislation to be implemented in 2004 makes engines with a power output between 19 and
37 kW subject to Tier II emission limit values. The emission limits for these engines do not
require the use of after-treatment equipment.

Engines  within  the  19-37  kW  power  band  are  already  covered  by  Directive  97/68,  but  are
subject to only one set of limit values. The Tier II limit values in US legislation are somewhat
more  stringent  than  the  ones  in  Directive  97/68/EC,  especially  as  regards  particulate  matter
(see below). The inventory carried out in 1994 also indicates that the contribution to overall
emissions  by  those  engines  is  not  negligible.  In  addition,  discussions  with  the  industry
concerned indicate that they prefer to align by incorporating the US legislation into Directive
97/68/EC.

Regulation/Stan
dard

HC+NOx
(g/kWh)

HC
(g/kWh)

NOx
(g/kWh)

PM
(g/kWh)

US Tier III
19-37 Kw

7.5

Directive
97/6818-37 kW

-

-

1.5

-

8.0

0.60

0.8

3.4.2.

Implementation dates for Stage III

Whatever scenario is adopted will of course be closely linked to implementation dates. In this
respect, for the power band above 37 kW, Scenario I could be implemented (in stages) as from
2006,  since  in  any  case  manufacturers  have  to  meet  the  requirements  of  the  US  market.
Scenario 2 will need a longer lead time, at least as regards PM limit values, since additional
requirements are imposed on engine manufacturers and the use of low-sulphur fuel has to be

12

made mandatory in all Member States. For Scenario 3, a longer lead time is also needed for
the  PM  requirements.  To  give  manufacturers  enough  development  time  it  is  reasonable  to
assume  that  the  PM  standards  can  enter  into  force  around  2009-2011.  For  Scenario  4,
theuncertainty  on  the  availability  of  NOx  after-treatment  equipment  in  the  non-road  sector
and especially  concerning  the final decision for  the on-road sector  in  EU is  greater.  Further
clarifications  therefore  are  needed  before  a  decision  can  be  made  on  the  implementation  of
limit values based on the use of aftertreatment equipment for NOx.

For  power  band  19-37  kW  the  corresponding  US  legislation  is  to  be  implemented  in  2004.
However, for practical reasons, it is not possible to introduce it into the EU before 2006.

One  specific  issue  is  implementation  dates  for  constant-speed  engines.  These  are  exempted
under Directive 97/68/EC as it stands. However, under the amendment described above these
engines will become subject to emission limit values, though not until 31 December 2006. To
give manufacturers a reasonable lead time the entry  into force date for these engines should
therefore be some years later than for other types of engines.

For some types  of  equipment  covered in  Directive 97/68/EC new  noise limit values will  be
implemented  in  2006  (Directive  2000/14/EC).  It  would  have  been  advantageous  to  co-
ordinate the implementation dates. However it is not possible to have an enter into force date
for stage IIIA by (next) 2006 for all kind of engines. At the revision of Directive 2000/14/EC
on noise, foreseen by 2005, the need for future co-ordination of implementation dates will be
taken into account.

3.4.3. Conclusions

To properly address environmental needs, Stage III limit values should be introduced for NOx
as  well  as  for  PM.  They  should  be  based  on  the  best  available  technology,  they  should  be
applicable to NRMM and they would have to be globally aligned.

In doing so the limit values for gaseous pollutants (Stage III A) would be equivalent to the US
Tier III standards for power bands above 37 kW and to the Tier II standards for the 19-37 kW
power band. They should be implemented in stages starting on 31 December 2006. The PM
limit  values  (Stage  III  B)  for  the  power  bands  above  37  kW  should  be  based  on  the
assumption  that PM traps, or technology  with  a  similar  effect,  will  be  available  in  the  non-
road sector. To allow the necessary lead time, those limit values should be implemented in the
EU in stages starting on 31 December 2009. However the necessary fuel will not be available
in the USA until a year later and to maintain the alignment and to offer the industry a global
market the implementation should start a year later, 31 December 2010.

To  ensure  that  the  necessary  technology  is  generally  available,  a  review  clause  should  be
inserted to the effect that the Commission should review technical progress so as to confirm
the PM limit values and propose any necessary  exemptions  not  later that 2006. This review
should  also  consider  a  Stage  IV  set  of  limit  values  for  NOx  based  on  the  availability  and
feasibility  of  using  after-treatment  equipment  and  also  consider  a  further  tightening  of  the
limit values for engines in the powerband 19-37 kW.

13

A Stage III set of limit values in Directive 97/68/EC should thus be implemented in two steps
as follows:

Category: Net power

Carbon monoxide

Sum  of  hydrocarbons  and
oxides of nitrogen

(P)

(kW)

(CO)

(g/kWh)

(HC+NOx)

(g/kWh)

H: 130 kW (cid:1) P (cid:1) 560 kW

I: 75 kW (cid:1) P < 130 kW

J: 37 kW (cid:1) P <75 kW

K: 19 kW (cid:1) P <37 kW

3.5

5.0

5.0

5.5

Table: Stage III A limit values

4.0

4.0

4.7

7.5

Particulates

(PT)

(g/kWh)

0.2

0.3

0.4

0.6

Category: Net power

Carbon monoxide

Sum  of  hydrocarbons  and
oxides of nitrogen

Particulates1

(PT)

(g/kWh)

0,025

0,025

0,025

(P)

(kW)

(CO)

(g/kWh)

L: 130 kW (cid:1) P (cid:1) 560 kW

M: 75 kW (cid:1) P < 130 kW

N: 37 kW (cid:1) P <75 kW

3.5

5.0

5.0

Table: Stage III B limit values

(HC+NOx)

(g/kWh)

4.0

4.0

4.7

Category: Net power

Entry into force dates

(P )

H: 130 kW (cid:1) P (cid:1) 560 kW

31 December 2005

I: 75 kW (cid:1) P < 130 kW

31 December 2006

J: 37 kW (cid:1) P <75 kW

31 December 2007

K: 19 kW (cid:1) P <37 kW

31 December 2005

Table:  Stage  III  A.  Entry into force dates  (placing  on the  market dates.)  For  constant speed
engines the implementation dates for Stage III B should also be used for gaseous pollutants.

1

PM  standards  subject  to  a  technical  review  by  the  end  of  2006.  For  applications  where  PM  trap  technology  or
similar is not possible the following limit values could tentatively apply: 0,15; 0.20; 0.25.

14

                                                
Category: Net power

Entry into force dates

(P)

L: 130 kW (cid:1) P (cid:1) 560 kW

31 December 2010

M: 75 kW (cid:1) P < 130 kW

31 December 2010

N: 37 kW (cid:1) P <75 kW

31 December 2011

Table: Stage III B. Entry into force dates (placing on the market dates).

For  inland  waterway  vessels  the  following  limit  values  and  implementation  dates  will  be
used:

Category: swept volume/net
power

(SV/P)

(litres per cylinder/kW)

Carbon monoxid

Sum  of  hydrocarbons  and
oxides of nitrogen

(CO)

(g/kWh)

(HC+NOx)

(g/kWh)

Particulates

(PT)

(g/kWh)

0.40

0.30

0.20

0.20

0.27

0.50

0.50

0.50

0.50

V1:1 SV≤ 0,9 and P>37 kW 5.0

V1:2 0,9<SV≤1,2

V1:3 1,2<SV≤2,5

V1:4 2,5<SV≤5

V2:1 5<SV≤15

V2:2 15<SV≤20 and

P ≤3300 kW

V2:3 15<SV≤20

and P>3300 kW

V2:4 20<SV≤25

V2:5 25<SV≤30

5.0

5.0

5.0

5.0

5.0

5.0

5.0

5.0

7.5

7.2

7.2

7.2

7.8

8.7

9.8

9.8

11.0

Table: Limit values for inland waterway vessels

15

Category:

Entry into force dates

V1:1

V1:2

V1:3

V1:4

V2

31 December 2006

31 December 2006

31 December 2006

31 December 2008

31 December 2008

Table: Entry into force dates for emission limits for inland waterway vessels (placing on the
market dates).

3.5.

The importance of fuel quality

3.5.1. General

The two stages of  emission standards in  the  current Directive 97/68/EC can be met without
any  specific  fuel  quality  requirements  therefore  some  Member  States  also  allow  the  use  of
heating oil for non-road mobile machinery. Other Member States require the same fuel quality
to be used as for the on-road sector. One Member State – Spain - has introduced a separate
fuel quality standard for the NRMM sector. The main reason for the choice of fuel quality is
taxation  and  not  the  production  cost  of  different  fuel  qualities.  The  tax  on  heating  oil  is
normally low while the tax on motor fuel is high.

With  more  stringent  emission  standards  and  more  sophisticated  technology  needed  to  meet
those standards, fuel  quality  will  become  more  important.  The  most  important  parameter  in
this  respect  is  sulphur  content.  A  high  sulphur  content  will  cause  higher  emissions  of
particulates and in addition, if after-treatment devices have to be used to meet emission limits,
might damage or reduce the efficiency of after-treatment equipment. To prevent this, sulphur
content has to be at least below 50 ppm.

Requirements concerning sulphur content in gas oils are laid down in Directive 98/70/EC (on
petrol  and  diesel  fuels  for  on-road  and  non-road  vehicles)  and  Directive  1999/32/EC  (on
heating oil). According to the latter Directive, the maximum sulphur content of gas oil used
for purposes other than on-road vehicles is 2000 ppm. From 2008 this limit will be lowered to
1000 ppm.

Directive 98/70/EC requires a maximum sulphur content of 50 ppm for diesel intended for use
in on-road vehicles from 1 January 2005. A proposed amendment to this Directive, currently
awaiting a final decision in the Council and the EP, would further tighten this maximum to 10
ppm.  It  would  seem  that  the  Council  and  the  European  Parliament  will  agree  to  make  this
mandatory from 2009.

In principle the quality of diesel fuel for use in non-road mobile machinery is also covered by
Directive  98/70/EC.  However,  since  there  is  no  technical  need  for  any  specific  fuel
requirements to meet the Stage I and II emission standards it has been left to Member States
to decide on sulphur content as long as it does not exceed the content specified in Directive

16

1999/32/EC and is not more stringent than for on-road applications. The Common position on
the  proposed  amendment  mentioned  above  states  that  the  Commission  should  present  more
detailed  requirements  on  diesel  fuel  for  the  non-road  sector  when  proposing  emission  limit
values for Stage III.

Today  about  9%  of  gas  oil  consumption  is  for  non-road  purposes  -  if  inland  waterways  are
included.  About  50%  is  used  for  the  on-road  sector  and  about  40%  as  heating  oil.  At
European level, there is no separate non-road diesel quality, and with a market share of less
than  10%  this  situation  is  unlikely  to  change  in  the  future.  At  national  level,  special  fuel
qualities might well be made available.

As  previously  mentioned,  for  tax  reasons,  some  Member  States  are  allowing  low-taxed
heating oil to be used for non-road applications too. In this respect, there might be a need for
specific action, especially in the agricultural sector. A marker is now added to low-tax oil to
help enforce the legislation and check that low-tax fuel is not used for applications where on-
road  quality  should  be  used.  If  a  better  fuel  quality  than  heating  oil  is  needed  to  meet  the
Stage III limit values, certain practical problems might arise in those Member States that still
want to allow the use of low-tax fuel.

This  might  be  solved  in  different  ways,  for  instance  by  having  one  dyed  grade  gas  oil  for
heating purposes, a second dyed grade diesel for NRMM, which could also be used as heating
oil by  farmers  with  one  storage  tank,  and  a  third  non-dyed  (high-tax)  diesel  oil  for  on-road
purposes.

It is up to Member States to decide on what tax policy they want to apply  and also on  how
they want to implement the distribution systems. The example above is only to illustrate that
there are solutions  which can  also be used  in  those Member States that  want  to  continue  to
allow low-tax diesel oil to be used for NRMM purposes in the future.

Given the above conclusions on limit values, we will in the future have a situation where the
Stage III A limit values for gaseous pollutants can be met by using heating oil. However, to
meet the Stage III B PM limit values, a fuel with a maximum of 10-50 ppm sulphur must be
used. Thus, it is necessary  to  ensure that low-sulphur  fuel is used once the PM limit values
enter into force or in Member States that want to encourage earlier implementation of those
limit values.

3.5.2.

Reference fuel

The reference fuel used for type-approval purposes should reflect the fuel quality used under
real  operational  conditions.  Since  legislation  in  the  Member  States  differs  as  regards  the
market  fuel,  the  current  reference  fuel  specification  is  a  compromise.  The  most  important
parameter - sulphur content - must be between 1000 and 2000 ppm.

The proposed Stage  III  B limit values  for particulate  emissions  will  require  the  use  of  low-
sulphur  fuel  (10-50  ppm).  Accordingly,  the  reference  fuel  should  be  changed  to  reflect  the
proposal to  make the  use of  low-sulphur fuel mandatory for  all  non-road  mobile  machinery
applications.  In  addition,  some  Member  States  might  want  to  offer  incentives  to  encourage
manufacturers  to  meet  the  more  stringent  PM  standards  before  they  become  mandatory.  In
this  case  manufacturers  should  be  allowed  to  use  a  low-sulphur  reference  fuel  when  type-
approving engines.

17

3.5.3. Conclusions

The  availability  of  appropriate  fuels  will  not  be  a  limiting  factor  in  introducing  Stage  III
emission limits for non-road mobile machinery.

Stage  III A limit values can  be  met without any further fuel quality specifications. To meet
the III B limit values the sulphur content of the fuel must be in the order of 10-50 ppm at the
highest.  The  Commission  will  propose  an  amendment  to  Directive  98/70/EC  to  secure  the
European-wide introduction of the relevant fuel.

To reflect this a separate reference fuel should be brought into use once the Stage III  B PM
limit  values  enter  into  force,  or  when  a  manufacturer  voluntarily  type-approves  engine
families to meet those limit values.

3.6.

Durability requirements

The  corresponding  US  legislation  includes  definitions  on  the  useful  life  during  which  limit
values must be met, as well as provisions for recall schemes.

Europe has generally been later in implementing this kind of legislation. It was introduced for
light  vehicles  by  Directive  98/69/EC  and  there  are  ongoing  efforts  to  introduce  similar
provisions for heavy duty vehicles, intended to enter into force in 2005.

In  principle  the  same  kind  of  legislation  should  also  apply  to  non-road  engines.  However,
since  this  kind  of  equipment  is  not  registered,  it  is  more  difficult  to  implement  in-use
compliance  programmes.  However,  a  first  step  would  be  to  define  useful  life  for  different
categories of engines and to require that manufacturers establish deterioration factors to apply
to type-approval.

A further stage – to include in-use compliance checks and recalls – could be addressed in the
technical review mentioned above.

3.6.1. Conclusions

A definition of useful life should be included in the legislation - 3000 hours for engines below
37 kW and 5000 hours for engines at or above 37 kW.

The  manufacturer  has  to  establish  a  deterioration  factor  for  each  engine  family.  If  the
established factor is below 1.0, then 1.0 should be used.

3.7.

Costs and cost-effectiveness

3.7.1. Costs

The  main  issues  for  the  development  of  the  stage  III  limit  values  have  been  to  establish  a
world  wide  aligned  legislation  based  on  the  environmental  need  and  the  availability  of
the  cost  –
emission  reducing 
effectiveness/benefit of the proposal and to see to that it is in the same order of magnitude as
other  introduced  legislation  addressing  the  same  environmental  issues,  bearing  in  mind  that
the benefits for manufacturers of an alignment can not be included

technology.  Even  so 

to  examine 

important 

is 

it 

As mentioned above there is a lack of precise information on the number of NRMM and the
use of them. In addition existing emission models are normally developed for road transport

18

and  is  not  possible  to  use  for  NRMM  emission  calculations.  To  overcome  this  shortage  of
information the calculations have been made on an engine basis, taking into account the life
time  emissions  and  life  time  costs  of  the  engines.  Using  the  different  power  bands  in  the
current directive the following life costs to meet the stage III limit values (stage IIIA + stage
IIIB) have been used in a consultant study that the Commission has carried out. These costs
include the cost for  equipment and engineering. It should though be noted that the costs for
the power band 18-37 kW includes a further tightening of the PM limit  values compared to
the one proposed in this amendment. In the absence of better estimates those costs have been
used in the analyses.

Engine power (kW)

18-37

37-75

75-130

130-560

Cost 
(€/engine)

for 

emission 

technology

1, 800

3, 775

5, 300

8, 400

Table: Additional cost (technology and engineering) for the implementation of stage III limit
values.

Source: Consultant study by VTT Process.

In addition to those cost there will be additional costs for low sulphur fuel, which is required
to meet the stage IIIB limit values on PM. Low sulphur fuel is not required for engines in the
power band 18-37 kW since no after-treatment device is needed. However in practice it will
be  difficult  to  distribute  fuel  with  higher  sulphur  content  only  for  that  category  of  engines.
Therefore  the  additional  cost  for  low  sulphur  fuel  has  been  added  also  to  this  category  of
engines.

In  a  separate  consultant  study  carried  out  by  Beicip-Franlab  the  cost  for  going  from  a  fuel
with  a  sulphur  content  of  1000  ppm  to  one  with  a  sulphur  content  of  10  ppm  has  been
estimated to 1,5-1,9 Euro-cent per litre. Net value of 1.5 Euro-cent per litre has been used for
the further analyses.

Engine power (kW)

18-37

37-75

75-130

130-560

Life time fuel consumption (litre)

19.938

47.150

95.120

333.500

Additional cost for low sulphur fuel (€)

 299

 707

 1.426

5.002

Table: Additional costs for the use of low sulphur fuel.

Sources: Consultant studies by VTT Process and Beicip-Franlab.

Costs of this kind are difficult to estimate with sufficient accuracy since these are standards
that are to be implemented a long time in the future. Experience in the on-road sector shows
that  these  costs  are  normally  overestimated  when  comparing  real  costs  with  the  estimates
made  as  the  legislation  was  decided  upon.  In  addition,  since  the  market  is  almost  100%
global, it could be argued that the costs of meeting the Stage III A standards are already there
since the EPA has confirmed that it will be continuing with its Tier III standards. Furthermore
the consultant has based its costs on the use of two sets of particulate filters for all engines
which is not likely to happen. The corresponding cost calculations (preliminary) made by the
US EPA indicates much lower costs.

19

3.7.2.

Benefits

In  a  separate  consultant  study,  “Estimates  of  the  marginal  external  costs  of  air  pollution  in
Europe”,  carried  out  by  the  company  Netcen,  the  marginal  external  costs  for  different
pollutants were estimated as follows:

Benefits of emission reductionsin rural areas 

Country

Austria

Belgium

Denmark

Finland

France

Germany

Greece

Ireland

Italy

Netherlands

Portugal

Spain

Sweden

UK

EU-15 Average

NOx
(€/tonne)

PM 
(€/tonne)

2.5

SO2
(€/tonne)

6,800

4,700

3,300

1,500

8,200

4,100

6,000

2,800

7,100

4,000

4,100

4,700

2,600

2,600

4,200

14,000

22,000

 5,400

 1,400

15,000

16,000

 7,800

 4,100

12,000

18,000

5,800

7,900

1,700

9,700

14,000

7,200

7,900

3,300

 970

7,400

6,100

4,100

2,600

5,000

7,000

3,300

3,700

1,700

4,500

5,200

Benefits of emission reductions  in urban areas

City size

100,000 people

500,000 people

NOx
(€/tonne)

PM 
(€/tonne)

2,5

SO2
(€/tonne)

Same as rural

33,000

Same as rural

165,000

1,000,000 people

Same as rural

247,500

Several million people

Same as rural

495,000

20

6,000

30,000

45,000

90,000

As  can  be  seen  in  the  tables,  the  marginal  costs  differ  widely  depending  on  where  the
emissions  take  place.  In  1999  80%  of  the  population  in  EU  lived  in  urban  areas.  However,
since  a  large  share  of  the  engines  is  used  in  the  agricultural  sector  and  thus  the  emissions
taking place in rural areas the following assumptions are made concerning the use of and the
emissions from  NRMM:  50%  of  the  emissions  take  place  in  rural  areas,  30%  in  cities  with
100.000 inhabitants, 8% in cities with 500.000 inhabitants and 2% in cities with more than 1
million inhabitants.

Under those assumptions the benefits will be the following:

NOx – 4200 €/tonne

PM – 36420 €/tonne

SO2 – 8220 €/tonne

3.7.3.

Emission reductions

In the above study by VTT Process the life time “savings” (tonne/engine) of the emissions has
been estimated to the following.

Engine power band (kW)

19-37

37-75

75-130

130-560

SN. Savings NOx (tonne)

0.1

0.4

0.7

2.9

SPM. Savings PM (tonne)

0.023

0.043

0.068

0.184

SS. Savings SO2 (30 % PM) (tonne)

0.034

0.057

0.114

0.399

3.7.4. Cost- efficiency (feasibility)

Based on the data above and on data given by equipment manufacturers on the distribution of
different engine sizes in Europe the overall benefits of the package proposed for the NRMM
engines shows that the benefits per engine are about 75 Euro higher than the costs. The same
calculation  indicates  that  the  overall  result  is  due  to  high  benefits  for  larger  engines.No
separate calculation has been made for inland waterway vessels.

3.7.5. Conclusions

Cost  estimates  on  technical  measures  that  are  supposed  to  be  implemented  rather  far  in  the
future  will  for  natural  reasons  be  uncertain.  Experience  shows  that  at  the  time  of  the
development of the legislation those costs are overestimated compared to the real costs when
they once have to be implemented.

Furthermore  in  this  particular  case  it  could  be  questionable  whether  the  cost  for  stage  IIIA
should  be  fully  included  since  the  majority  of  manufacturers  anyhow  has  to  meet  the
corresponding US legislation which is already decided on. For the engines in the power band
19-37 kW the consultant’s cost estimates are based on a stage IIIB limit value for PM of 0.3
g/kWh  whilst  the  proposal  only  requires  0.6  g/kWh.  The  consultant  has  also  assumed  that
every  engine  must  use  two  sets  of  PM  traps,  which  can  be  questioned  since  durability

21

requirements are included in the proposal. Furthermore preliminary cost calculations made by
the EPA indicate much lower values.

On the other hand no cost for increased fuel consumption has been inserted. The use of more
advanced technology will open the possibility for manufacturers to improve the fuel economy
and thereby compensate for the fuel penalty that will occur due to the use of particulate traps.

Furthermore great uncertainties are linked to the estimates of benefits. In this respect it should
be noted that all particles emitted from NRMM are so called nano-particles, which seems to
be more and more a concern from a health point of view..

Bearing those uncertainties, which can go in both directions, in mind it seems as if the stage
III package as such is positive from a cost benefit point of view. It should however be noted
that this overall outcome is due to the very positive effect on large engines and this underlines
the importance of the technical review which is suggested as a part of the package.

3.8.

Flexibilities

3.8.1. General

Non-road  mobile  machinery  have  a  large  number  of  different  applications.  Furthermore,
although legislation in this field is basically geared towards engine manufacturers. it will still
involve many manufacturers of equipment (OEMs), who may or may not produce engines as
well. To cover these different aspects and yet not just aim at the lowest common denominator
in  legislation,  or  delay  its  introduction  and  consequently  the  use  of  advanced  technology,
certain so called flexibilities (exemptions) should be used. This is also a concept that has been
used in the corresponding US legislation.

On  the  other  hand,  legislation  should  be  as  clear  as  possible  so  that  it  is  given  the  same
interpretation  in  all  Member  States.  Consequently,  there  should  be  as  few  exemptions  as
possible.  It  is  also  difficult  to  copy  US  legislation  completely  due  to  the  different
administrative systems.

The following cases are covered by special arrangements in the legislation.

3.8.2.

Engine manufacturers

3.8.2.1. Small volume manufacturers

Small volume manufacturers have fewer resources for developing new technology. They also
have fewer products to cover the development costs. If  they  are not  operating  on the  global
market they are not forced to comply with US legislation.

3.8.2.2. Small volume engine families

Basically the development costs should be covered by the specific engine family. The smaller
the  engine  family  the  more  difficult  to  do  so.  It  is  especially  difficult  for  small-volume
manufacturers who cannot transfer costs to other engine families.

3.8.3.

Equipment manufacturers

Directive 97/68/EC is an engine Directive, meaning that it is the engine manufacturer that has
to  meet  the  standards.  Ultimately,  however,  engines  are  mounted  into  pieces  of  equipment,

22

either by the engine manufacturers themselves or by separate equipment manufacturers. In the
latter  case  especially  it  is  necessary  to  allow  the  equipment  manufacturer  time  to  adapt  his
product to the design of the engine. One way of meeting this need would be to allow engines
to  be  placed  on  the  market  over  a  certain  period  providing  that  the  engines  have  been
produced before the entry into force dates.

The current Directive allows for this, but makes it subject to decisions by individual Member
States. In theory the whole market would be open even if only one Member State accepted the
option. However, in practice this creates problems for manufacturers since they then have to
place  their  engines  on  the  market  in  that  Member  State  (or  States)  and  then  transport  the
engine  to  the  customer  in  another  Member  State.  It  could  be  argued  that  this  option  might
encourage a manufacturer to produce and stockpile a large number of engines just before the
new  emission  limits  enter  into  force.  However,  in  practice  this  is  unlikely  to  happen  as  the
economic uncertainty for the manufacturer would be too great. To simplify the legislation this
option  of  designing  equipment  for  engines  already  manufactured  should  not  be  left  to  the
discretion of individual Member States.

3.8.4.

Possible solutions

The  corresponding  US  legislation  allows  a  certain  amount  of  flexibility.  One  essential
element of this flexibility is the use of averaging, banking and trading of emissions. Basically
this allows an engine manufacturer to place an engine that exceeds the emission limit values
on the market providing that this is offset by placing on the  market  engines  with  emissions
below the limit values and that the average emission of the total production is below the limit
values.  This  is  a  way  of  allowing  the  necessary  flexibility  without  losing  environmental
benefits.

The Commission proposal on emissions from spark ignition engines (COM(2000) 840 final)
included this system. However, both the Council and the European Parliament rejected it as
too  complicated  and  unfair.  This  time  the  Commission  is  not  proposing  to  include  such  a
system.

Nevertheless, manufacturers will face similar problems in complying with EU legislation, so
they have to be addressed properly. Any solution will involve deviation from the conventional
type-approval  system  and  it  is  therefore  essential  to  implement  flexibile  arrangements  that
will  be  interpreted  in  the  same  way  by  different  Member  States  and  create  a  minimum  of
administrative burden.

A way of doing this is to basically use the same concept as is used in the US legislation when
dealing  with the difficulties for equipment manufacturers.  In other  words,  a manufacturer is
allowed to use a limited number of engines that only comply with the previous emission limit
standards.  He  can  then  use  this  flexibility  in  the  way  that  best  helps  him  solve  his  specific
problems.  One  manufacturer  might  need  more  time  for  technical  development  of  his
production  while  another  might  need  a  longer  development  time  only  for  a  small  engine
family. The benefit of this kind of flexibility is that approval authorities do not have to decide
on the details, but that this framework  ensures  that  the  environmental  consequences  will  be
known in advance and will be the same whatever strategy the manufacturer is using.

3.8.5. Conclusions

To resolve the special difficulties which might occur for equipment manufacturers, including
small  volume  manufacturers,  and  for  small-volume  products,  a  voluntary  flexibility  scheme

23

should be introduced whereby an OEM is allowed, for a four-year period, to use engines that
only comply with the previous stage of limit  values.  The  number  of  engines  in  each  engine
power  band  should  be  limited  to  20%  of  one  year’s  production  or  a  maximum  of  units
depending on powerband (50, 100, 150 or 200).

3.9.

Technical feasibility review

As mentioned above, it might ultimately prove difficult to apply trap technology  (or  similar
solutions) to certain kinds of NRMM by the time Stage III B limit values enter into force. For
this  kind  of  equipment  it  might  be  necessary  to  delay  the  implementation  dates  or  to  allow
exemptions from the Stage III B limits. In the latter case some other limit values should apply,
probably  based  on  those  in  the  Scenario  2  described  in  point  3.4.1.1  above,  meaning  a  PM
limit  value  40%  lower  than  the  current  Stage  II  limits.  A  technical  feasibility  study  should
therefore  be  carried  out  on  the  applicability  of  PM  trap  technology  in  the  non-road  mobile
machinery  sector,  and  any  exemptions  necessary  should  be  proposed.  This  study,  and  the
decisions linked to it, have to be carried out  early  enough to allow  manufacturers  time they
need.  On  the  other  hand,  if  it  is  done  too  early  it  will  not  leave  enough  time  for  technical
development  and  might  then  result  in  exemptions  even  though  the  technology  would  have
been available by the date of implementation. As a compromise solution between those two
needs  a  proposal  from  the  Commission  should  be  presented  not  later  than  by  the  end  of
December 2006.

Some other issues of major interest might be included in the study and, if appropriate, in the
proposals. One such topic is of course the need to further reduce NOx, which is closely linked
to the availability of after-treatment equipment. By addressing this in the technical review in
2006, information from the on-going CAFE project will be available on the overall need for
further reductions and on the cost-efficiency of measures in other sectors.

Other topics that could be included in the technical review are:

- the need to reconsider the scope of the Directive concerning railway applications according
to the last developments and possibilities offered by the new railway legislative framework, in
particular in the field of railway interoperabililty,

-  the  need  for  and  feasibility  of  in-use  compliance  checks  and  specific  test  procedures  for
railway applications.

4.

CONTENT OF THE PROPOSAL

4.1.

Scope of the Directive (Annex I)

The current Directive 97/68/EC covers CI engines from 18 kW to 560 kW. The corresponding
US legislation covers the power band 19-560 kW. To achieve alignment the lower limit of 19
kW will be used in Directive 97/68/EC from the dates when Stage III enters into force.

Railway locomotives are currently excluded from the scope of the Directive, but there is no
specific definition. A definition of railway locomotives is now to be included in accordance
with  the  corresponding  US  legislation.  This  means  that  small  engines  used  in  rail-cars  for
example will be covered. This is line with what the Commission stated in its White Paper on a
Common Transport Policy (COM (2001) 370).

24

Engines  used  in  inland  waterway  vessels  will  also  be  included  within  the  scope  of  the
Directive.

4.2.

Test procedure (Annex III)

The current procedure  for measuring emissions  in  Directive 97/68/EC is based on a steady-
state test cycle - the ISO C1 8-mode cycle.

Most  non-road  engines  are  used  for  applications  that  are  largely  transient  in  nature.  Even
equipment  such  as  pumps  and  generators,  which  operate  mostly  at  constant  speeds,  may
depart  from  steady-state  operation  due  to  variations  in  engine  loads  over  time.  Thanks  to
widespread  co-operation  between  the  authorities  and  industry  in  USA,  Japan  and  Europe,
efforts  have  been  made  to  develop  a  new  test  cycle  which  will  better  reflect  this.  This  co-
operation has resulted in a new transient test cycle that can also be run on what are known as
eddy-current dynamometers with a significant cost saving (between one third and one quarter)
of the conventional equipment (AC dyno or DC dyno) used for transient tests.

The  future  Stage  IIIB  standards  for  particulate  matter  will  be  based  on  this  new  dedicated
transient  test  procedure  to  better  reflect  actual  operating  conditions  and  in  particular  to
represent real emissions of particulates and to ensure that emissions reduction technology is
developed to take account of those driving conditions. For measurement of gaseous emissions
it will be optional for the manufacturer to use either the new transient test cycle or the current
steady-state test procedure.

A significant cost saving (one fifth or less) can be obtained if the transient test is carried out
by  means  of  the  partial  flow  dilution  systems  instead  of  using  the  conventional  CVS
(Constant  Volume  Sampling)  facility.  In  this  respect,  manufacturers  will  still  be  able  to
choose between full-flow systems or partial-flow systems as at present.

4.3.

Limit values for Stage III (Annex I)

To properly address environmental needs, Stage III limit values are being introduced for NOx
as well as for PM. They are based on the best available technology, and applied as feasible to
NRMM, taking account of the need for global alignment.

Accordingly,  the  Stage  III  limit  values  for  gaseous  pollutants  (Stage  III  A)  are  basically
equivalent to the US Tier  III standards for the power bands above 37 kW and to the Tier II
standards for power band 19-37 kW. The PM limit values (Stage III B) for the power bands
above 37 kW are based on the  assumption  that  PM traps, or technology  with similar effect,
will be generally available in the non-road sector if enough time is allowed.

To ensure that the necessary technology is available a review clause is included to the effect
that  the  Commission  should  review  technical  progress,  confirm  the  PM  limit  values  and
propose  necessary  exemptions  not  later  that  2006.  This  review  could  include  an  additional
study into the possible use of after-treatment equipment to reduce gaseous pollutants (NOx) at
a later stage.

4.4.

Implementation dates for Stage III (Article 9)

For the power band above 37 kW, the Stage III A limit values can be implemented (in stages)
from 2006,  since  by  then  manufacturers  will  be  having  to  meet  the  requirements  of  the  US
market.  For  Stage  III  B  limit  values  on  particulates,  a  longer  lead  time  is  needed.  To  give

25

manufacturers enough time for the necessary technical development work, those limit values
will enter into force in stages between 2010 and 2012.

For  power band  19-37  kW,  the  corresponding  US  legislation  is  to  be  implemented  in  2004.
However, for practical reasons, it is not possible to introduce it into the EU before 2006.

A  specific  issue  is  implementation  dates  for  constant-speed  engines.  These  are  exempt  in
Directive  97/68/EC.  However,  following  the  amendment  on  spark-ignition  engines  recently
decided  upon  by  the  Council  and  the  European  Parliament,  they  will  be  covered  as  of  31
December  2006,  which  is  3-6  years  later  than  for  other  types  of  engine.  To  allow
manufacturers reasonable  time  the  entry  into  force  dates  for  this  kind  of  engines  have  been
adjusted accordingly.

4.5.

Fuel quality

4.5.1. General

The two stages of  emission standards in the  current Directive 97/68/EC can  be met  without
any specific requirements as regards fuel quality. To meet the proposed Stage III B standards
for particulates, however, a low-sulphur fuel (below 50 ppm) will have to be used. A separate
amendment  to  Directive  98/70/EC  will  therefore  be  proposed  by  the  Commission  in  good
time before the entry into force dates of those limit values.

4.5.2.

Reference fuel

The reference fuel used for type-approval purposes should reflect the fuel quality used under
real operating conditions. Since legislation on market fuels in the Member States differs, the
current reference fuel specification is a compromise. The most important parameter - sulphur
content - must be between 1000 and 2000 ppm.

The proposed  Stage  III  B limit values for particulate emissions will  require  the  use  of  low-
sulphur fuel. To reflect this, a reference fuel, equivalent to the one used for on-road vehicle, is
included.  The  manufacturer  may  use  this  fuel  quality  when  type-approving  engines  to  meet
the Stage III B limit values, whether mandatory or voluntary.

4.6.

Durability requirements (Annex III – Appendix 5)

The corresponding US legislation includes definitions of the useful life during which the limit
values must be complied with, as well as provisions on recall schemes.

Since  this  kind  of  equipment  is  not  registered,  it  is  more  difficult  to  carry  out  in-use
compliance  programmes.  Therefore,  at  this  initial  stage,  useful  life  is  defined  only  for  the
different categories of engines – 3000-5000 hours for engines below 37 kW and 8000 hours
for engines of 37 kW or over -  and the manufacturers are required to establish deterioration
factors to be used at the type-approval stage.

A further stage – to include in-use compliance checks and recalls – could be addressed in the
technical review mentioned above.

4.7.

Flexibilities (Article 9 and Annex XIV)

Directive 97/68/EC is an engine Directive, meaning that it is the engine manufacturer that has
to  meet  the  standards.  Ultimately,  however,  engines  are  mounted  into  pieces  of  equipment,

26

either by the engine manufacturers themselves or by separate equipment manufacturers. In the
latter  case  especially  it  is  necessary  to  allow  the  equipment  manufacturer  time  to  adapt  his
product  to  the  design  of  the  engine.  Specific  problems  in  this  respect  will  occur  for  small-
volume manufacturers, or in the case of small-volume products.

To provide a flexible approach, two possibilities have been introduced.

The first is to allow equipment manufacturers to use “old” engines for a period of two years
providing that those engines are produced before the date of entry into force of the new limit
values. This option is already included in the current Directive, but subject to the decision of a
Member State.

The second is a voluntary option allowing equipment manufacturers to use a limited number
of engines that  comply  only with  the previous limit values. The number of these  engines  is
limited  to  20%  of  one  year’s  production  within  each  power  band  or  a  maximum  of  units
depending on powerband (50, 100, 150 or 200) and they can be used for the period between
two  stages  of  limit  values.  This  allows  each  manufacturer  to  adopt  the  solution  which  best
suits  his  situation;  one  manufacturer  might  have  problems  with  one  engine  family  while
another  manufacturer  might  be  suffering  from  a  general  delay  with  the  development  of  his
products. Under this option, the  environmental  consequences are known in  advance  and the
main responsibility for dealing with the difficulties is transferred to the manufacturers. This is
also the best way of solving potential discrepancies between small and big manufacturers.

A  similar  option  is  provided  in  the  corresponding  US  legislation,  which  also  includes  a
number of other flexibilities like averaging and banking. Some of these other options might
be  practical  in  the  USA  since  the  legislation  there  is  implemented  by  one  single
administration. In Europe, theoretically 15 different approval authorities are involved and it is
not therefore practical to introduce all of those different options.

The European engine and equipment manufacturer organisations (Euromot and CECE/CEMA
respectively)  have  explained  that  they  are  satisfied  with  the  solution  proposed.  In  the
Commission's opinion, these organisations represent the whole range of manufacturers.

4.8.

Technical feasibility study

As mentioned above, a technical feasibility study should be carried out into whether PM trap
technology can be applied in the non-road mobile machinery sector, if appropriate proposing
which  applications  should  meet  only  the  less  stringent  PM  standards.  This  study  has  to  be
carried out early enough to give manufacturers information on the appropriate limit values in
good  time.  On  the  other  hand,  it  must  allow  reasonable  time  for  the  necessary  technical
development  be  carried  out.  A  compromise  solution  is  for  the  Commission  to  present  any
proposals by December 2006 at the latest.

27

2002/0304 (COD)

Proposal for a

DIRECTIVE OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL

amending Directive 97/68/EC on the approximation of the laws of the Member States
relating to measures against the emission of gaseous and particulate pollutants from
internal combustion engines to be installed in non-road mobile machinery

(Text with EEA relevance)

THE EUROPEAN PARLIAMENT AND THE COUNCIL OF THE EUROPEAN UNION,

Having  regard  to  the  Treaty  establishing  the  European  Community,  and  in  particular
Article 95 thereof,

Having regard to the proposal from the Commission1,

Having regard to the opinion of the European Economic and Social Committee2,

Acting in accordance with the procedure laid down in Article 251 of the Treaty3,

Whereas:

(1) 

(2) 

(3) 

(4) 

1 
2 
3 
4 
5 

Directive  97/68/EC  of  the  European  Parliament  and  of  the  Council  of  16  December
1997  on  the  approximation  of  the  laws  of  the  Member  States  relating  to  measures
against the emissions of  gaseous  and  particulate  pollutants  from  internal  combustion
engines  to  be  installed  in  non-road  mobile  machinery4  implements  two  stages  of
emission limit values for compression ignition engines and calls on the Commission to
propose  a  further  reduction  in  emission  limits,  taking  into  account  the  global
availability  of  techniques  for  controlling  air  polluting  emissions  from  compression
engine and the air quality situation.

The Auto-Oil programme5 concluded that further measures are needed to improve the
future  air  quality  of  theCommunity,  especially  as  regards  ozone  formation  and
emissions of particulate matter.

Advanced technology to reduce emissions  from  compression ignition  engines on  on-
road  vehicles  is  already  available  to  a  large  extent  and  such  technology  should,  to  a
large extent, be applicable to the non-road sector.

There  are  still  some  uncertainties  regarding  the  situation  around  2010  as  to  the  cost
effectiveness of using after-treatment equipment for particulate matter (PM) emissions

OJ L […], [.. .. ..], p. […].
OJ L […], [.. .. ..], p. […].
OJ L […], [.. .. ..], p. […].
OJ L 59, 27.2.1998, p. 1.
COM(2000) final

28

                                                
on small engines and on the availability of after-treatment equipment to reduce oxides
of  nitrogen  (Nox)  emissions.  A  technical  review  should  be  carried  out  before  31
December 2006 and, where appropriate, exemptions or delayed enter into force dates
for  PM  limit  values  and  tighter  limit  values  for  gaseous  pollutants  should  be
considered.

(5) 

(6) 

(7) 

(8) 

(9) 

A transient test procedure is needed  to  cover  the  operational  conditions  used  by  this
kind of machinery under real working conditions.

The proposed package of Stage III limit values should be aligned as far as possible on
developments  in  the  United  States  so  as  to  offer  manufacturers  a  global  market  for
their engine concepts.

Emission  standards  should  also  be  introduced  for  certain  railway  and  marine
applications to help promote them as environmentally friendly modes of transport.

Because of the technology needed to meet the Stage III B limits for PM emissions, the
sulphur  content  of  the  fuel  must  be  reduced  from  today’s  levels  in  many  Member
States. A reference fuel that reflects the fuel market situation should be defined.

Emission  performance  during  the  full  useful  life  of  the  engines  is  of  importance.
Durability  requirements  should  be  introduced  to  avoid  deterioration  of  emission
performance.

(10) 

It is necessary to introduce special arrangements for equipment manufacturers to give
them time to design their products and to handle small series production.

(11)  Since the objectives of the action to be taken to improve the future air quality situation
cannot  be  sufficiently  achieved  by  the  Member  States  since  necessary  emission
regulations  concerning  products  have  to  be  regulated  at  Community  level,  the
Community  may  adopt  measures,  in  accordance  with  the  principle  of  subsidiarity  as
set out in Article 5 of the Treaty. In accordance with the principle of proportionality,
as set out in that Article, this Directive does not go beyond what is necessary in order
to achieve those objectives.

(12)  Directive 97/68/EC should therefore be amended accordingly,

HAVE ADOPTED THIS DIRECTIVE:

Article 1

Directive 97/68/EC is amended as follows:

(1)

In Article 2 the following indent is added:

-

 “inland waterway vessel” shall mean a vessel having a length of 20 metres or
more, having a volume of 100 m3 or more according to the formula defined in
Annex I, Section 2, point 2.8a, or tugs or pusher craft having been built to tow
or to push or to move alongside vessels of 20 meters or more.”

29

(2)

In Article 2 the following subparagraph is added:

“The definition in the 16th indent of the first subparagraph does not include vessels
intended for passenger transport carrying no more than 12 people in addition to the
crew,  ferries,  recreational  craft  with  a  length  of  less  than  24  metres  (as  defined  in
article 1 (2) of Directive 94/25/EC), service craft belonging to supervisory authorities
and  fire-service  vessels,  naval  vessels  and  sea-going  vessels,  including  sea-going
tugs  and  pusher  craft  operating  or  based  on  tidal  waters  or  temporarily  on  inland
waterways,  provided  that  they  carry  a  valid  navigation  or  safety  certificates  as
defined in Annex I, Section 2, point 2.8b.”

(3)

In Article 4 the following paragraph 6 is added:

"6.

For  engines  placed  on  the  market  under  a  “flexible  scheme”,  the
procedure in Annex XIII shall apply in addition to paragraph 1 to 5."

(4)

In Article 6 the following paragraph 5 is added:

"5. Engines  placed  on  the  market  under  a  “flexible  scheme”  should  be

labelled in accordance with Annex XIII.”

(5)

Article 8 is amended as follows:

(a)

The heading is replaced by “placing on the market”:

(b)

In paragraph 1 the word “new” is deleted.

(6)

Article 9 is amended as follows:

(a)

In the introductory phrase of paragraph 3 the words “and shall refuse to grant
any other type-approval for non-road mobile machinery in which an engine is
installed” is replaced by “and shall refuse to grant any other type-approval for
non-road  mobile  machinery,  not  already  placed  on  the  market,  in  which  an
engine is installed”.

 (b) The following paragraphs 3a, 3b and 3c are inserted

“3a. TYPE-APPROVAL  of  STAGE 
CATEGORIES H, I, J and K)

III  A  ENGINES 

(ENGINE

Member  States  shall  refuse  to  grant  type-approval  for  the  following
engine types or families and to issue the document as described in Annex
VI, and shall refuse to grant any other type-approval for non-road mobile
machinery  in  which  an  engine,  not  already  placed  on  the  market,  is
installed:

– 

– 

H:  after  30  June  2005  for  engines  –  other  than  constant  speed
engines - of a power output: 130 kW ≤ P ≤ 560 kW,

I: after 31 December 2005 for engines – other than constant speed
engines - of a power output: 75 kW ≤ P < 130 kW,

30

– 

– 

J: after 31 December 2006 for engines – other than constant speed
engines - of a power output: 37 kW ≤ P <75 kW,

K: after 31 December 2005 for engines – other than constant speed
engines - of a power output: 19 kW ≤ P <37 kW,

where the engine fails to meet the requirements specified in this Directive
and  where  the  emissions  of  gaseous  pollutants  from  the  engine  do  not
comply  with  the  limit  values  as  set  out  in  the  table  in  section  4.2.3.  of
Annex I.

3b. TYPE-APPROVAL  OF  STAGE 
CATEGORIES K, L, M and N)

III  B  ENGINES 

(ENGINE

Member  States  shall  refuse  to  grant  type-approval  for  engine  types  or
families and to issue the  document as described in Annex VI,  and shall
refuse to grant any other type-approval for non-road mobile machinery in
which an engine, not already placed on the market, is installed:

– 

– 

Constant speed K engines: after 31 December 2009 for engines of a
power output: 19 kW ≤ P <37 kW,

L  and  constant  speed  H  engines:  after  31  December  2009  for
engines of a power output: 130 kW ≤ P ≤ 560 kW,

–  M  and  constant  speed  I  engines:  after  31  December  2009  for

engines of a power output: 75 kW ≤ P < 130 kW,

– 

N  and  constant  speed  J  engines:  after  31  December  2010  for
engines of a power output: 37 kW ≤ P < 75 kW,

where the engine fails to meet the requirements specified in this Directive
and where the emissions of particulate pollutants from the engine do not
comply  with  the  limit  values  set  out  in  the  table  in  Section  4.2.3.  of
Annex I."

“3c. TYPE-APPROVAL  OF  ENGINES  USED  IN  INLAND  WATERWAY

VESSELS (ENGINE CATEGORIES V)

Member  States  shall  refuse  to  grant  type-approval  for  engine  types  or
families and to issue the document as described in Annex VI:

– 

– 

– 

V1:1: after 31 December 2005 for engines of a power output above
37 kW and a swept volume below 0.9 litres per cylinder,

V1:2:  after  30  June  2005  for  engines  with  swept  volume  at  or
above 0.9 but below 1.2 litres per cylinder,

V1:3:  after  30  June  2005  for  engines  with  swept  volume  at  or
above 1.2 but below 2.5 litres per cylinder and a power output and
an engine power output of :37 kW ≤ P < 75 kW,

31

– 

– 

V1:4: after 31 December 2006 for engines with swept volume at or
above 2.5 but below 5 litres per cylinder,

V2:  after  31  December  2007  for  engines  with  a  swept  volume
above 5 litres per cylinder,

where the engine fails to meet the requirements specified in this Directive
and where the emissions of particulate pollutants from the engine do not
comply with the limit values as set out in the table in section 4.1.2.4 of
Annex I”.

(c)

Paragraph 4 is amended as follows

(i)

In the heading the words “registration and” are deleted

(ii)

In  the  first  subparagraph  the  words  “…  Member  States  shall  permit  the
registration, where applicable, and placing on the market of new engines,…” is
replaced by “… Member States shall permit the placing on the market of new
engines”

(iii) The second and third subparagraphs are replaced by the following:

"Stage III A

– 

– 

– 

– 

– 

– 

– 

– 

– 

category H: 31 December 2005

category I: 31 December 2006

category J: 31 December 2007

category K: 31 December 2006

category V1:1: 31 December 2006

category V1:2: 31 December 2006

category V1:3: 31 December 2006

category V1:4: 31 December 2008

categories V2: 31 December 2008

For  constant  speed  engines  of  categories  H,  J,  K  and  L  respectively,  the
implementation dates are four years later than the dates mentioned above.

Stage III B

– 

– 

– 

category L: 31 December 2010

category M: 31 December 2010

category N: 31 December 2011

32

For each category, the above requirements shall be postponed by two years in
respect of engines with a production date prior to the said date.

The  permission  granted  for  one  stage  of  emission  limit  values  shall  be
terminated with effect from the mandatory implementation of the next stage of
limit values."

(7)

In Article 10 the following paragraph 3 is added:

Engines  may  be  placed  on  the  market  under  a  “flexible  scheme”  in

"3.
accordance with the provisions in Annex XIII."

(8)

The Annexes are amended as follows:

(a) Annexes I, III, V, VII and XII are amended in accordance with Annex I to this

Directive.

(b) Annex VI is replaced by the text in Annex II to this Directive.

(c) A new Annex XIII as set out in Annex III to this Directive is added.

The Commission shall, not later than 31 December 2006

Article 2

– 

– 

– 

– 

– 

– 

consider the available technology with a view to confirming Stage III B limit values
and  evaluating  the  possible  need  for  additional  flexibilities,  exemptions  or  later
introduction dates for certain types of equipment or engines,

evaluate the need to use a separate test procedure for railway applications,

evaluate  the  need  to  amend  the  scope  of  the  Directive  according  to  the  last
developments  in  the  railway  transport  and  interoperability  legislative  framework  in
order to cover, in the most effective way, all railway applications.

consider tightening the limit values for emissions of gaseous pollutants in the light of
environmental  needs  and  technological  developments  in  after-treatment  equipment
for NOx reduction in the on-road sector,

consider the need to introduce a further set of limit values for engines to be used in
inland waterway vessels,

consider  the need to  introduce  emission  limit  values  for  engines  below  19  kW  and
above 560 kW,

and submit, where appropriate proposals to the European Parliament and the Council.

Article 3

1.

Member  States  shall  bring  into  force  the  laws,  regulations  and  administrative
provisions necessary to comply with this Directive [within 12 months of its entry into
force] [before 1 July 2005]. They shall forthwith inform the Commission thereof.

33

When  Member  States  adopt  those  provisions,  they  shall  contain  a  reference  to  this
Directive  or  be  accompanied  by  such  a  reference  on  the  occasion  of  their  official
publication. Member States shall determine how such reference is to be made.

2.

Member  States  shall  communicate  to  the  Commission  the  texts  of  the  main
provisions of the national law that they adopt in the field governed by this Directive.

This Directive shall enter into force on the twentieth day following that of its publication in
the Official Journal of the European Communities.

Article 4

Article 5

This Directive is addressed to the Member States.

Done at Brussels,

For the European Parliament
The President

For the Council
The President

34

ANNEX I

1.

ANNEX I TO DIRECTIVE 97/68 IS AMENDED AS FOLLOWS:

a)

In point B of section 1, last subparagraph

the  word  “ships”  is  replaced  by  :  “Ships,  except  vessels  intended  for  use  on

inland waterwayss”

In pointC of section 1, last subparagraph the words “Railway locomotives” are
replaced  by:  “  Railway  locomotives  that  are  not  designed  to  carry  any
passengers or freight by themselves.”

Section 2 is amended as follows:

The following points 2.8a and 2.8b are inserted:

b)

c)

(i)

“2.8a: “volume of 1003 or more” with regard to a vessel intended for use
on  inland  waterways  means  its  volume  calculated  on  the  formula
LxBxT,  “L”  being  the  maximum  length  of  the  hull,  excluding
rudder and bowsprit, “B” being the maximum breadth of the hull in
metres, measured to the outer  edge  of the  shell plating (excluding
paddle  wheels,  rubbing  strakes,  etc.)  and  “T”  being  the  vertical
distance between  the  lowest moulded point of the hull or the keel
and the maximum draught line.

2.8b: “valid navigation or safety certificated” means

(a)

a  certificate  proving  conformity  with  the  1974  International
Convention for the Safety of Life at Sea (SOLAS), as amended, or
equivalent or

(b)

a  certificate  proving  conformity  with  the  1966  International  Convention  on
Load  Lines,  as  amended,  or  equivalent,  and  an  IOPP  certificate  proving
conformity  with  the  1973  International  Convention  for  the  Prevention  of
Pollution from Ships (MARPOL), as amended.” (ii)
The follwing section 2.17
is inserted:

“”test  cycle”  means  a  sequence  of  test  points  each  with  a  defined  speed  and
torque to be followed by the engine under steady state (NRSC test) or transient
operating conditions (NRTC test);”

(iii) Section 2.17 is renumbered to 2.18 and replaced by the following:

35

2.18.

Symbols and abbreviations

2.18.1. Symbols for test parameters

Symbol
A/Fst
AP
AT
Aver

C1
Cd

Conc

Concc

Concd

Conce

d

DF
fa
GAIRD
GAIRW
GDILW
GEDFW
GEXHW
GFUEL
GSE
GT
GTOTW
Ha
Hd
HREF
i

KH
Kp
KV
KW,a
KW,d
KW,e
KW,r
L
Md
MDIL
MEDFW
MEXHW

Unit
-

m²

m²

m3/h
kg/h

-

-

Term
Stoichiometric air/fuel ratio

Cross sectional area of the isokinetic sampling probe

Cross sectional area of the exhaust pipe

Weighted average values for:
-volumeflow
– mass flow

Carbon 1 equivalent hydrocarbon

Discharge coefficient of the SSV

Background corrected concentration

Concentration (with suffix of the component nominating)

ppm
Vol%
ppm
Vol%
ppm
Vol%
ppm Vol% Concentrtion of the pollutant measured in the diluted exhaust gas

Concentration of the pollutant measured in the dilution air

m

-

-

kg/h

kg/h

kg/h

kg/h

kg/h

kg/h

kg/h
cm3/min
kg/h

g/kg

g/kg

g/kg

-

-

-

-

-

-

-

-

%

mg

kg
kg

kg

Diameter

Dilution factor

Laboratory atmospheric factor

Intake air mass flow rate on dry basis

Intake air mass flow rate on wet basis

Dilution air mass flow rate on wet basis

Equivalent diluted exhaust gas mass flow rate on wet basis

Exhaust gas mass flow rate on wet basis

Fuel mass flow rate

Sampled exhaust mass flow rate

Tracer gas flow rate

Diluted exhaust gas mass flow rate on wet basis

Absolute humidity of the intake air

Absolute humidity of the dilution air

Reference value of absolute humidity (10,71 g/kg)

Subscript denoting an individual mode (for NRSC test)
or an instananeous value (for NRTC test)

Humidity correction factor for NOx
Humidity correction factor for particulate

CFV calibration function

Dry to wet correction factor for the intake air

Dry to wet correction factor for the dilution air

Dry to wet correction factor for the diluted exhaust gas

Dry to wet correction factor for the raw exhaust gas

Percent torque related to the maximum torque for the test speed

Particulate sample mass of the dilution air collected

Mass of the dilution air sample passed through the particulate sampling filters
Mass of equivalent diluted exhaust gas over the cycle

Total exhaust mass flow over the cycle

36

Mf
Mf,p
Mf,b
Mgas

MPT

MSAM

MSE

MSEC
MTOT
MTOTW
MTOTW,I

mass
NP
nref
spn(cid:1)
P
p1
PA
Pa

PAE

PB

pd
PM

Pm
ps
q
Qs
r

Ra
Rd
Re
Rf
T

t
Ta
TD
Tref
Tsp
t10
t50
t90

mg

mg

mg

g

g

kg

kg

kg

kg

kg

kg

g/h

-
min-1
s-2
kW

kPa

kPa

kPa

kW

kPa

kPa

kW

kW

kPa

-

m³/s

-

%

%

-

-

K

s

K

K

K

Particulate sample mass collected

Particulate sample mass collected on primary filter

Particulate sample mass collected on back-up filter

Total mass of gaseous pollutant over the cycle

Total mass of particulate over the cycle

Mass of the diluted exhaust sample passed through the particulate sampling filters

Sampled exhaust mass over the cycle

Mass of secondary dilution air

Total mass of double diluted exhaust over the cycle

Total mass of diluted exhaust gas passing the dilution tunnel over the cycle on wet basis

Instantaneous mass of diluted exhaust gas passing the dilution tunnel on wet basis

Subscript denoting emissions mass flow (rate)

Total revolutions of PDP over the cycle

Reference engine speed for NRTC test

Derivative of the engine speed

Power, brake uncorrected

Pressure depression at pump inlet of PDP

Absolute pressure

Saturation vapour pressure of the engine intake air
(ISO 3046: psy=PSY test ambient)

Declared total power absorbed by auxiliaries fitted for the test which are not required by
paragraph 2.4 of this Annex

Total atmospheric pressure (ISO 3046:
Px=PX Site ambient total pressure
Py=PY Test ambient total pressure)
Saturation vapour pressure of the dilution air

Maximum power at the test speed under test conditions (see Annex VII, Appendix 1)

Power measured on test bed

Dry atmospheric pressure

Dilution ratio

CVS volume flow rate

Ratio of cross sectional areas of isokinetic probe and exhaust pipe

Relative humidity of the intake air

Relative humidity of the dilution air

Reynolds number

FID response factor

Absolute temperature

Measuring time

Absolute temperature of the intake air

Absolute dew point temperature

Reference temperature (of combustion air: 298 K)

N·m

Demanded torque of the transient cycle

s

s

s

Time between step input and 10% of final reading

Time between step input and 50% of final reading

Time between step input and 90% of final reading

37

∆ti
V0
Wact
WF
WFE
X0

ΘD
ß
(cid:1)
(cid:1)EXH

s

m³/rev

kWh

-

-

Time interval for instantaneous CFV flow

PDP volume flow rate at actual conditions

Actual cycle work of NRTC

Weighting factor

Effective weighting factor

m³/rev

Calibration function of PDP volume flow rate

kg·m2
-

-

kg/m³

Rotational inertia of the eddy-current dynamometer

Ratio of the SSV throat diameter, d, to the inlet pipe inner diameter

Relative air/fuel ratio, actual A/F devided by stoichiometric A/F

Density of the exhaust gas

2.18.2. Symbols for chemical components

CH4

C3H8

C2H6

CO

CO2

Methane

Propane

Ethane

Carbon monoxide

Carbon dioxide

DOP

Di-octylphtalate

H2O

HC

NOx

NO

NO2

O2

PT

Water

Hydrocarbons

Oxides of nitrogen

Nitric oxide

Nitrogen dioxide

Oxygen

Particulates

PTFE

Polytetrafluoroethylene

38

2.18.3. Abbreviations

CFV

CLD

CI

FID

FS

HCLD

HFID

NDIR

Critical Flow Venturi

Chemiluminescent detector

Compression Ignition

Flame Ionisation Detector

Full scale

Heated 
Detector

Heated 
Detector

Chemiluminescent

Flame 

Ionisation

Non-Dispersive 
Analyser

Infrared

NG

Natural Gas

NRSC

Non-Road Steady Cycle

NRTC

Non-Road Transient Cycle

PDP

Positive _Displacement Pump

SI

Spark Ignition

SSV

Sub-Sonic Venturi

(d)

Section 3 is amended as follows:

(i)

The following section 3.1.4. is inserted

“3.1.4. "labels in accordance with annex XIV, … if the engine is placed on the market under

flexible scheme provisions.”

d)

Section 4 is amended as follows:

-

The following section 4.1.2.4 is added:

“4.1.2.4.The  emissions  of  the  carbon  monoxide,  the  emissions  of  the  sum  of  hydrocarbons
and oxides of nitrogen and the emissions of particulates obtained shall for stage IIIA
not exceed amounts shown in the table below:

39

Engines for use in other applications than inland waterway vessels:

Category: Net power

Carbon monoxide

Sum  of  hydrocarbons  and
oxides of nitrogen

(P )

(kW)

(CO)

(g/kWh)

(HC+NOx)

(g/kWh)

H: 130 kW ≤ P ≤ 560 kW

I: 75 kW ≤ P < 130 kW

J: 37 kW ≤ P <75 kW

K: 19 kW ≤ P <37 kW

3,5

5,0

5,0

5,5

4,0

4,0

4,7

7,5

Particulates

(PT)

(g/kWh)

0,2

0,3

0,4

0,6

Engines for use in inland waterway vessels

Category: swept volume/net
power

Carbon monoxide

Sum  of  hydrocarbons  and
oxides of nitrogen

Particulates

(SV/P )

(litres per cylinder/kW)

(CO)

(g/kWh)

V1:1 SV≤ 0,9 and P>37 kW 5.0

V1:2 0,9<SV≤ 1,2

V1:3 1,2<SV≤ 2,5

V1:4 2,5<SV≤ 5

V2:1 5<SV≤ 15

V2:2 15<SV≤ 20 and

P ≤3300 kW

V2:3 15<SV≤ 20

and P>3300 kW

V2:4 20<SV≤ 25

V2:5 25<SV≤ 30

5.0

5.0

5.0

5.0

5.0

5.0

5.0

5.0

(HC+NOx)

(g/kWh)

7.5

7.2

7.2

7.2

7.8

8.7

9.8

9.8

11.0

(PT)

(g/kWh)

0.40

0.30

0.20

0.20

0.27

0.50

0.50

0.50

0.50

-

The 

following 

section 

4.1.2.5 

is 

inserted:

40

4.1.2.5.
The  emissions  of  the  carbon  monoxide,  the  emissions  of  the  sum  of
hydrocarbons and oxides of nitrogen and the emissions of particulates obtained shall
for stage IIIB not exceed amounts shown in the table below:

Category: Net power

Carbon
monoxide

Sum  of  hydrocarbons  and
oxides of nitrogen

(P )

(kW)

(CO)

(HC+NOx)

(g/kWh)

(g/kWh)

L: 130 kW ≤ P ≤ 560 kW1

M: 75 kW ≤ P < 130 kW

N: 37 kW ≤ P <75 kW

3,5

5,0

5,0

4,0

4,0

4,7

-

The following section 4.1.2.6 is inserted:

Particulates

(PT)

(g/kWh)

0,025

0,025

0,025

4.1.2.6. The limit values in sections 4.1.2.4 and 4.1.2.5 shall include deterioration calculated

in accordance with Annex III, appendix 5.

Section 4.1.2.4 is renumbered to 4.1.2.7

ANNEX III IS AMENDED AS FOLLOWS:

Section 1 is amended as follows:

In paragraph 1.1 the following paragraph is added:

-

3.

(a)

-

“Two  test  cycles  are  described  that  shall  be  applied  according  to  the  provisions  of
Annex I, Section 1:

-

-

the  NRSC  (Non-Road  Steady  Cycle)  which  shall  be  used  for  stages  I,  II  and
IIIA and for constant speed engines as well for stage IIIB,

the  NRTC  (Non-Road  Transient  Cycle)  which  shall  be  used  measurement  of
particulate emissions for stage IIIB for all engines but constant speed engines.
By the choice of the manufacturer this test can be used also for stage IIA and
for the gaseous pollutants in stage IIIB.

For  engines  intended  to  use  in  inland  waterway  vessels  the  ISO  test  procedure  as
specified  by  ISO  8178  and  IMO  MARPOL  73/78,  Annex  VI  (NOx  Code)  shall  be
used

-

The following paragraph 1.3 is inserted:

41

                                                
1.3.

Measurement principle:

The  engine  exhaust  emissions  to  be  measured  include  the  gaseous  components  (carbon
monoxide,  total  hydrocarbons  and  oxides  of  nitrogen),  and  the  particulates.  Additionally,
carbon dioxide is often  used  as  a  tracer  gas for determining the dilution  ratio  of  partial  and
full flow dilution systems. Good engineering practice recommends the general measurement
of carbon dioxide as an excellent tool for the detection of measurement problems during the
test run.

1.3.1. NRSC Test:

During  a  prescribed  sequence  of  operating  conditions,  with  the  engines  warmed  up,  the
amounts of the above exhaust emissions shall be examined continuously by taking a sample
from  the  raw  exhaust  gas.  The  test  cycle  consists  of  a  number  of  speed  and  torque  (load)
modes,  which  cover  the  typical  operating  range  of  diesel  engines.  During  each  mode  the
concentration of each gaseous pollutant, exhaust flow and power output shall be determined,
and the measured values weighted. The particulate sample shall be diluted  with conditioned
ambient  air.  One  sample  over  the  complete  test  procedure  shall  be  taken  and  collected  on
suitable filters.

Alternatively,  a  sample  shall  be  taken  on  separate  filters,  one  for  each  mode,  and  cycle-
weighted results computed.

The  grams  of  each  pollutant  emitted  per  kilowatt  hour  shall  be  calculated  as  described  in
Appendix 3 to this Annex.

1.3.2. NRTC Test:

During a prescribed transient cycle of operating conditions, with the engine warmed up, based
closely  on  the  operating  conditions  of  diesel  engines  installed  in  nonroad  machinery,  the
above  pollutants  shall  be  examined.  Using  the  engine  torque  and  speed  feedback  signals  of
the engine dynamometer, the power shall be integrated with respect to the time of the cycle,
resulting  in  the  work  produced  by  the  engine  over  the  cycle.  The  concentrations  of  the
gaseous  components  shall  be  determined  over  the  cycle,  either  in  the  raw  exhaust  gas  by
integration  of  the  analyzer  signal  in  accordance  with  Appendix  3  to  this  Annex,  or  in  the
diluted exhaust gas of a CVS full-flow dilution system by integration or by bag sampling in
accordance with  Appendix 3 to  this  Annex.  For  particulates,  a  proportional  sample  shall  be
collected from the  diluted  exhaust gas  on  a  specified  filter  by either  partial  flow dilution or
full-flow dilution. Depending on the method used, the diluted or undiluted exhaust gas flow
rate shall be determined over the cycle to calculate the mass emission values of the pollutants.
The  mass  emission  values  shall  be  related  to  the  engine  work  to  give  the  grams  of  each
pollutant emitted per kilowatt-hour.

(b)

-

Section 2 is changed as follows:

Paragraph 2.2.3 is replaced by the following:

2.2.3.

Engines with charge air cooling

The charge  air  temperature  shall be  recorded and, at  the  declared  rated  speed  and  full  load,
shall be within (cid:2) 5 K of the maximum charge air temperature specified by the manufacturer.
The temperature of the cooling medium shall be at least 293 K (20°C).

42

If  a  test  shop  system  or  external  blower  is  used,  the  charge  air  temperature  shall  be  set  to
within  (cid:2)  5  K  of  the  maximum  charge  air  temperature  specified  by  the  manufacturer  at  the
speed of the declared  maximum  power and full load.  Coolant  temperature  and  coolant  flow
rate  of  the  charge  air  cooler  at  the  above  set  point  shall  not  be  changed  for  the  whole  test
cycle. The charge air cooler volume shall be based upon good engineering practice and typical
vehicle/machinery applications.

Optionally, the setting of the charge air cooler may be done in accordance with SAE J 1937 as
published in January 1995.

-

The text under paragraph 2.3. Engine air inlet system is replaced by the following:

The test engine shall be  equipped  with  an  air  inlet  system  presenting  an  air  inlet  restriction
within (cid:2) 300 Pa of the value specified by the manufacturer for a clean air cleaner at the engine
operating conditions as specified by the manufacturer, which result in maximum air flow. The
restrictions are to be set at rated speed and full load A test shop system may be used, provided
it duplicates actual engine operating conditions.

-

The text under paragraph 2.4 Engine exhaust system is replaced by the following:

The test engine shall be equipped with an exhaust system with exhaust back pressure within (cid:2)
650 Pa of the value specified by the manufacturer as the engine operating conditions resulting
in maximum declared power.

If the engine is equipped with an exhaust after-treatment device, the exhaust pipe shall have
the  same  diameter  as  found  in-use  for  at  least  4  four  diameters  upstream  to  the  inlet  of  the
beginning of the  expansion  section  containing the after-treatment device. The distance from
the exhaust manifold flange or turbocharger outlet to the exhaust after-treatment device shall
be  the  same  as  in  the  vehicle  configuration  or  within  the  distance  specifications  of  the
manufacturer. The exhaust backpressure or restriction shall follow the same criteria as above,
and  may  be  set  with  a  valve.  The  aftertreatment  container  may  be  removed  during  dummy
tests and during engine mapping, and replaced with an equivalent container having an inactive
catalyst support.”

-

(c)

-

Paragraph 2.8 is deleted.

Section 3 is amended as follows:

The title of section 3 is replaced by:

“3.

TEST RUN (NRSC TEST)”

-

The following paragraph 3.1 is inserted:

“3.1.

Determination of dynamometer settings

The  basis  of  specific  emissions  measurement  is  uncorrected  brake  power  according  to  ISO
14396: 2002.

Certain  auxiliaries,  which  are  necessary  only  for  the  operation  of  the  machine  and  may  be
mounted on the engine should be removed for the test. The following incomplete list is given
as an example:

43

-

-

-

-

air compressor for brakes

power steering compressor

air conditioning compressor

pumps for hydraulic actuators

Where auxiliaries have not been removed, the power absorbed by them at the test speeds shall
be determined in order to calculate the dynamometer settings, except for engines where such
auxiliaries form an integral part of the engine (e.g. cooling fans for air cool engines).

The  settings  of  inlet  restriction  and  exhaust  pipe  backpressure  shall  be  adjusted  to  the
manufacturer's upper limits, in accordance with sections 2.3 and 2.4.

The  maximum  torque  values  at  the  specified  test  speeds  shall  be  determined  by
experimentation  in  order  to  calculate  the  torque  values  for  the  specified  test  modes.  For
engines  which  are  not  designed  to  operate  over  a  range  on  a  full  load  torque  curve,  the
maximum torque at the test speeds shall be declared by the manufacturer.

The engine setting for each test mode shall be calculated using the formula:

(cid:9)

S

(cid:1)

(cid:7)
(cid:5)
(cid:6)

(cid:8)

(cid:2)
xP
AE

P
M

L
100

(cid:4)
(cid:1)(cid:2)
(cid:3)

P

AE

If the ratio,

P
AE
P
M

03,0(cid:1)

the value of PAE may be verified by the technical authority granting type approval.

-

-

Current paragraphs 3.1 – 3.3 are renumbered to 3.2-3.4

Current  paragraph  3.4  is  renumbered  to  paragraph  3.5  and  the  text  replaced  by  the
following:

3.5.

Adjustment of the dilution ratio

The  particulate  sampling  system  shall  be  started  and  running  on  bypass  for  the  single  filter
method  (optional  for  the  multiple  filter  method).  The  particulate  background  level  of  the
dilution air may be determined by passing dilution air through the particulate filters. If filtered
dilution air is used, one measurement may be done at any time prior to, during, or  after the
test. If the dilution air is not filtered, the measurement must be done on one sample taken for
the duration of the test.

The dilution air shall be set to obtain a filter face temperature between 315 K (42 °C) and 325
K (52 °C) at each mode. The total dilution ratio shall not be less than four.

Note: For steady-state procedure, the filter temperature may be kept at or below the maximum
temperature of 325 K (52 °C) instead of respecting the temperature range of 42 °C – 52 °C.

44

For the single and multiple filter methods, the sample mass flow rate through the filter shall
be  maintained  at  a  constant  proportion  of  the  dilute  exhaust  mass  flow  rate  for  full  flow
systems  for  all  modes.  This  mass  ratio  shall  be  within  ±  5  %  with  respect  to  the  averaged
value of the mode, except for the first 10 seconds of each mode for systems without bypass
capability.  For  partial  flow  dilution  systems  with  single  filter  method,  the  mass  flow  rate
through  the  filter  shall  be  constant  within  ±  5  %  with  respect  to  the  averaged  value  of  the
mode, except for the first 10 seconds of each mode for systems without bypass capability.

For CO2 or NOx concentration controlled systems, the CO2 or NOx content of the dilution air
must  be  measured  at  the  beginning  and  at  the  end  of  each  test.  The  pre  and  post  test
background  CO2  or  NOx  concentration  measurements  of  the  dilution  air  must  be  within
100 ppm or 5 ppm of each other, respectively.

When  using  a  dilute  exhaust  gas  analysis  system,  the  relevant  background  concentrations
shall  be  determined  by  sampling  dilution  air  into  a  sampling  bag  over  the  complete  test
sequence.

Continuous  (non-bag)  background  concentration  may  be  taken  at  the  minimum  of  three
points, at the beginning, at the end, and a point near the middle of the cycle and averaged. At
the manufacturer's request background measurements may be omitted.

-

-

Current paragraphs 3.5-3.6 are renumbered to 3.6-3.7

Current paragraph 3.6.1 is replaced by the following:

3.7.1.

Equipment specification according to Section 1A of Annex I:

3.7.1.1. Specification A.

For  engines  covered  by  Section  1A(i)  of  Annex  I,  the  following  8-mode  cycle1  shall  be
followed in dynamometer operation on the test engine:

Mode Number

Engine Speed

1

2

3

4

5

6

7

8

Rated

Rated

Rated

Rated

Intermediate

Intermediate

Intermediate

Idle

Load

100

75

50

10

100

75

50

---

Weighting Factor

0,15

0,15

0,15

0,10

0,10

0,10

0,10

0,15

1

Note 1 shall be amended as follows: Identical with C1 cycle as described in Paragraph 8.3.1.1 of the ISO8178-4:
2002(E) standard.

45

                                                
3.7.1.2. Specification B.

For  engines  covered  by  Section  1A(ii)  of  Annex  I,  the  following  5-mode  cycle2  shall  be
followed in dynamometer operation on the test engine:

Mode Number

Engine Speed

1

2

3

4

5

Rated

Rated

Rated

Rated

Rated

Load

100

75

50

25

10

Weighting Factor

0,05

0,25

0,30

0,30

0,10

3.7.1.3 Specification C.

For engines intended to use in inland waterway vessels the ISO test procedure as specified by
ISO 8178 and IMO MARPOL 73/78, Annex VI (NOx Code) shall be used

The load figures are percentage values of the torque corresponding to the prime power rating
defined  as  the  maximum  power  available  during  a  variable  power  sequence,  which  may  be
run  for  an  unlimited  number  of  hours  per  year,  between  stated  maintenance  intervals  and
under the stated  ambient conditions, the maintenance being carried out as prescribed by  the
manufacturer.1"

-

(i)

(ii)

-

-

The current subparagraph 3.6.3 is changed as follows:

In the first section the word “cycle” is replaced by the word “cycles”

In the second section the first sentence will start “During each mode of the given test
cycle (the rest remains unchanged)”

The current paragraph 3.7 is renumbered to 3.8

The following section 4 is inserted:

4.

TEST RUN (NRTC TEST)

4.1.

Introduction

The  non-road  transient  cycle  (NRTC)  is  listed  in  Annex  III,  Appendix  4  as  a  second-by-
second  sequence  of  normalized  speed  and  torque  values  applicable  to  all  diesel  engines
covered by this Directive. In order to perform the test on an engine test cell, the normalised
values shall be converted to the actual values  for the individual engine under test, based on

2

1

Note  2  shall  be  amended  as  follows:  Identical  with  D2  cycle  as  described  in  Paragraph  8.4.1  of  the  ISO8178-4:
2002(E) standard.
For a better illustration of the prime power definition, see Figure 2 of ISO 8528-1: 1993(E) standard.

46

                                                
the  engine  mapping  curve.  This  conversion  is  referred  to  as  denormalisation,  and  the  test
cycle  developed  is  referred  to  as  the  reference  cycle  of  the  engine  to  be  tested.  With  these
reference  speed  and  torque  values,  the  cycle  shall  be  run  on  the  test  cell,  and  the  feedback
speed  and  torque  values  recorded.  In  order  to  validate  the  test  run,  a  regression  analysis
between reference and feedback speed and torque values shall be conducted upon completion
of the test.

4.2.

Engine mapping procedure

When generating the NRTC on the test cell, the  engine shall be mapped before running the
test cycle to determine the speed vs torque curve.

4.2.1. Determination of the mapping speed range

The minimum and maximum mapping speeds are defined as follows:

Minimum mapping speed

=

idle speed

nhi  x  1,02  or  speed  where  full  load  torque  drops  off  to
Maximum mapping speed
zero,  whichever  is  lower  (where  nhi  is  the  high  speed,  defined  as  the  highest  engine  speed
where 70% of the rated power is delivered).

=

4.2.2.

Engine mapping curve

The engine shall be warmed up at maximum power in order to stabilise the engine parameters
according to the recommendation of the manufacturer and  good  engineering practice. When
the  engine  is  stabilised,  the  engine  mapping  shall  be  performed  according  to  the  following
procedures.

4.2.2.1. Transient map

(a)

(b)

(c)

The engine shall be unloaded and operated at idle speed.

The engine shall be operated at full load setting of the injection pump at minimum
mapping speed.

The  engine  speed  shall  be  increased  at  an  average  rate  of  8  ±  1  min-1  /s  from
minimum  to  maximum  mapping  speed.  Engine  speed  and  torque  points  shall  be
recorded at a sample rate of at least one point per second.

4.2.2.2. Step map

(a)

(b)

(c)

The engine shall be unloaded and operated at idle speed.

The engine shall be operated at full load setting of the injection pump at minimum
mapping speed.

While maintaining full load, the minimum mapping speed shall be maintained for at
least 15 s, and the average torque during the last 5 s shall be recorded. The maximum
torque curve from minimum to maximum mapping speed shall be determined in no
greater than 100 ± 20 /min speed increments. Each test point shall be held for at least
15 s, and the average torque during the last 5 s shall be recorded.

47

4.2.3. Mapping curve generation

All  data  points  recorded  under  clause  4.2.2  shall  be  connected  using  linear  interpolation
between points. The resulting torque curve is the mapping curve and shall be used to convert
the  normalized  torque  values  of  the  engine  dynamometer  schedule  of  Annex  IV  into  actual
torque values for the test cycle, as described in clause 4.3.3.

4.2.4.

Alternate mapping

If a manufacturer believes that the above mapping techniques are unsafe or unrepresentative
for any given engine, alternate mapping techniques may be used. These alternate techniques
must  satisfy  the  intent  of  the  specified  mapping  procedures  to  determine  the  maximum
available  torque  at  all  engine  speeds  achieved  during  the  test  cycles.  Deviations  from  the
mapping techniques specified in this section for reasons of safety or representativeness shall
be  approved  by  the  parties  involved  along  with  the  justification  for  their  use.  In  no  case,
however,  shall  the  torque  curve  be  run  by  descending  engine  speeds  for  governed  or
turbocharged engines.

4.2.5.

Replicate tests

An engine need not be mapped before each and every test cycle. An engine must be remapped
prior to a test cycle if:

-

or,

-

an  unreasonable  amount  of  time  has  transpired  since  the  last  map,  as
determined by engineering judgement,

physical  changes  or  recalibrations  have  been  made  to  the  engine,  which  may
potentially affect engine performance.

4.3.

Generation of the reference test cycle

4.3.1.

Reference speed

The reference speed (nref) corresponds to the 100 % normalized speed values specified in the
engine dynamometer schedule of Annex III, Appendix 4. It is obvious that the actual engine
cycle resulting  from  denormalization  to  the  reference  speed  largely  depends  on  selection  of
the  proper  reference  speed.  The  reference  speed  shall  be  determined  by  the  following
definition:

nref = low speed + 0,95 * (high speed – low speed)

(the high speed is the highest engine speed where 70% of the rated power is delivered, while
the low speed is the lowest engine speed where 50% of the rated power is delivered).

4.3.2. Denormalization of engine speed

The speed shall be denormalized using the following equation:

Actual speed =

%speed

(cid:1)
reference

(cid:3)

speed

(cid:2)

idle

speed

(cid:2)

(cid:1)

idle

speed

100

48

 
 
 
4.3.3. Denormalization of engine torque

The  torque  values  in  the  engine  dynamometer  schedule  of  Annex  III,  Appendix  4  are
normalized to the maximum torque at the respective speed. The torque values of the reference
cycle shall be denormalized, using the mapping curve determined according to clause 4.2.2,
as follows:

Actual torque =

 %

torque

(cid:1)

 max.

torque

100

(5)

for the respective actual speed as determined in Section 4.3.2

4.3.4.

Example of denormalization procedure

As an example, the following test point shall be denormalized:

% speed = 43 %

% torque = 82 %

Given the following values:

reference speed

=

2200 /min

idle speed = 600 /min

results in

actual speed =

43

(cid:4)

(cid:1)2200 - 600(cid:2)
100

(cid:3)

600

=

1288 /min

With the maximum torque of 700 Nm observed from the mapping curve at 1288 /min

actual torque =

 700

82 (cid:4)(cid:5)
100

=

574 N(cid:1)m

4.4.

Dynamometer

4.4.1. When using a load cell, the torque signal shall be transferred to the engine axis and
the  inertia  of  the  dyno  shall  be  considered.  The  actual  engine  torque  is  the  torque
read  on  the  load  cell  plus  the  moment  of  inertia  of  the  brake  multiplied  by  the
angular acceleration. The control system has to perform this calculation in real time.

4.4.2.

If the engine is tested with an eddy-current dynamometer, it is recommended that the
T
sp

(cid:1)(cid:1)2
n

number of points, where the difference 

 is smaller than - 5% of

(cid:2)(cid:3)

(cid:1)(cid:2)

sp

(cid:2)

D

the  peak  torque,  does  not  exceed  30  (where  Tsp  is  the  demanded  torque,
  is  the
derivative  of  the  engine  speed  and·(cid:1)ΘD  is  the  rotational  inertia  of  the  eddy-current
dynamometer).

spn(cid:1)

49

 
4.5.

Emissions test run

The following flow chart outlines the test sequence.

Engine Preparation, Pre-test Measurements, Performance Checks and Calibrations

(cid:1)

Generate Engine Map (Maximum Torque Curve)

(cid:1)

Run one or more Practice Cycles as necessary to check engine/test cell/emissions systems

(cid:1)

START

(cid:1)

Run prescribed Preconditioning Cycle for a minimum of 20 minutes to condition engine and
particulate system including tunnel system (partial flow or full flow).

Particulates are collected on a dummy filter.

(cid:1)

With engine running, set PM system in by-pass mode and change PM filter to stabilized and
weighed sampling filter. Ready all other systems for sampling and data collection.

(cid:1)

Run Hot Cycle exhaust emissions test within 5 minutes either from engine shut down or from
running engine that has been brought down to idle conditions.

One or more Practice Cycles may be run as necessary to check engine, test cell and emissions
systems before the measurement cycle.

4.5.1.

Preparation of the sampling filters

At least one hour before the test, each filter shall be placed in a petri dish, which is protected
against  dust  contamination  and  allows  air  exchange,  and  placed  in  a  weighing  chamber  for
stabilization. At the end of the stabilization period, each filter shall be weighed and the weight
shall be recorded. The filter shall then be stored in a closed petri dish or sealed filter holder
until  needed  for  testing.  The  filter  shall  be  used  within  eight  hours  of  its  removal  from  the
weighing chamber. The tare weight shall be recorded.

4.5.2.

Installation of the measuring equipment

The  instrumentation  and  sample  probes  shall  be  installed  as  required.  The  tailpipe  shall  be
connected to the full flow dilution system, if used.

50

4.5.3.

Starting and preconditioning the dilution system and the engine

The  dilution  system  and  the  engine  shall  be  started  and  warmed  up.  The  sampling  system
preconditioning shall be conducted by operating the engine at a condition of rated-speed, 100
percent torque for a minimum of 20 minutes while simultaneously operating either the Partial
flow  Sampling  System  or  the  Full  flow  CVS  with  secondary  dilution  system.  Dummy
particulate matter emissions samples are then collected. Particulate sample filters need not be
stabilized  or  weighed,  and  may  be  discarded.  Filter  media  may  be  changed  during
conditioning  as  long  as  the  total  sampled  time  through  the  filters  and  sampling  system
exceeds 20 minutes. Flow rates shall be set at the approximate flow rates selected for transient
testing. Torque shall be reduced  from 100 percent torque  while maintaining the  rated  speed
condition  as  necessary  so  as  not  to  exceed  the  191  o  C  maximum  sample  zone  temperature
specifications.

4.5.4.

Starting the particulate sampling system

The  particulate  sampling  system  shall  be  started  and  run  on  by-pass.  The  particulate
background level of the dilution air may be determined by sampling the dilution air prior to
entrance  of  the  exhaust  into  the  dilution  tunnel.  It  is  preferred  that  background  particulate
sample  be  collected  during  the  transient  cycle  if  another  PM  sampling  system  is  available.
Otherwise, the PM sampling system used to collect transient cycle PM can be used. If filtered
dilution air is used, one measurement may be done prior to or after the test. If the dilution air
is not filtered, measurements should be carried out prior to the beginning and after the end of
the cycle and the values averaged.

4.5.5.

Adjustment of the dilution system

The  total  diluted  exhaust  gas  flow  of  a  full  flow  dilution  system  or  the  diluted  exhaust  gas
flow through a partial flow dilution system shall be set to eliminate water condensation in the
system, and to obtain a filter face temperature between 315 K (42°C) and 325 K (52°C).

4.5.6. Checking the analyzers

The emission analyzers shall be set at zero and spanned. If sample bags are used, they shall be
evacuated.

4.5.7.

Engine starting procedure

The stabilized engine shall be started within 5 min after completion of warm-up according to
the starting procedure recommended by the manufacturer in the owner's manual, using either
a production starter motor or the dynamometer. Optionally, the test may start within 5 min of
the engine preconditioning phase without shutting the engine off, when the engine has been
brought to an idle condition.

4.5.8. Cycle run

4.5.8.1. Test sequence

The  test  sequence  shall  commence  when  the  engine  is  started  from  shut  down  after  the
preconditioning phase or from idle conditions when starting directly from the preconditioning
phase with the engine running. The test shall be performed according to the reference cycle as
set out in Annex III, Appendix 4. Engine speed and torque command set points shall be issued
at  5  Hz  (10  Hz  recommended)  or  greater.  The  set  points  shall  be  calculated  by  linear

51

interpolation between the 1 Hz set points of the reference cycle. Feedback engine speed and
torque shall be recorded at least once every second during the test cycle, and the signals may
be electronically filtered.

4.5.8.2. Analyzer response

At the start of the engine or test sequence, if the cycle is started directly from preconditioning,
the measuring equipment shall be started, simultaneously:

-

-

-

-

start collecting or analyzing dilution air, if a full flow dilution system is used;

start  collecting  or  analyzing  raw  or  diluted  exhaust  gas,  depending  on  the
method used;

start  measuring  the  amount  of  diluted  exhaust  gas  and  the  required
temperatures and pressures;

start  recording  the  exhaust  gas  mass  flow  rate,  if  raw  exhaust  gas  analysis  is
used;

start recording the feedback data of speed and torque of the dynamometer.

If raw exhaust measurement is used, the emission concentrations (HC, CO and NOx) and the
exhaust gas mass flow rate shall be measured continuously and stored with at least 2 Hz on a
computer  system.  All  other  data  may  be  recorded  with  a  sample  rate  of  at  least  1  Hz.  For
analogue  analyzers  the  response  shall  be  recorded,  and  the  calibration  data  may  be  applied
online or offline during the data evaluation.

If  a  full  flow  dilution  system  is  used,  HC  and  NOx  shall  be  measured  continuously  in  the
dilution  tunnel  with  a  frequency  of  at  least  2  Hz.  The  average  concentrations  shall  be
determined by integrating the analyzer signals over the test cycle. The system response time
shall  be  no  greater  than  20  s,  and  shall  be  coordinated  with  CVS  flow  fluctuations  and
sampling time/test cycle offsets, if necessary. CO and CO2 shall be determined by integration
or  by  analyzing  the  concentrations  in  the  sample  bag,  collected  over  the  cycle.  The
concentrations of the gaseous pollutants in the dilution air shall be determined by integration
or by collection in the background bag. All other parameters that need to be measured shall be
recorded with a minimum of one measurement per second (1 Hz).

4.5.8.3. Particulate sampling

At the start of the engine or test sequence, if the cycle is started directly from preconditioning,
the particulate sampling system shall be switched from by-pass to collecting particulates.

If a partial flow dilution system is used, the sample pump(s) shall be adjusted so that the flow
rate  through  the  particulate  sample  probe  or  transfer  tube  is  maintained  proportional  to  the
exhaust mass flow rate.

If a full flow dilution system is used, the sample pump(s) shall be  adjusted so that the flow
rate through the particulate sample probe or transfer tube is maintained at a value within ± 5
%  of  the  set  flow  rate.  If  flow  compensation  (i.e.,  proportional  control  of  sample  flow)  is
used,  it  must  be  demonstrated  that  the  ratio  of  main  tunnel  flow  to  particulate  sample  flow
does  not  change  by  more  than  ±  5  %  of  its  set  value  (except  for  the  first  10  seconds  of
sampling).

52

Note:

For double dilution operation, sample flow is the net difference between the flow rate
through the sample filters and the secondary dilution airflow rate.

The average temperature and pressure at the gas meter(s) or flow instrumentation inlet shall
be recorded. If the set flow rate cannot be maintained over the complete cycle (within ± 5 %)
because  of  high  particulate  loading  on  the  filter,  the  test  shall  be  voided.  The  test  shall  be
rerun using a lower flow rate and/or a larger diameter filter.

4.5.8.4. Engine stalling

If  the  engine  stalls  anywhere  during  the  test  cycle,  the  engine  shall  be  preconditioned  and
restarted, and the test repeated. If a malfunction occurs in any of the required test equipment
during the test cycle, the test shall be voided.

4.5.8.5. Operations after test

At the completion of the test, the measurement of the exhaust gas mass flow rate, the diluted
exhaust  gas  volume,  the  gas  flow  into  the  collecting  bags  and  the  particulate  sample  pump
shall  be  stopped.  For  an  integrating  analyzer  system,  sampling  shall  continue  until  system
response times have elapsed.

The concentrations of the collecting bags, if used, shall be analyzed as soon as possible and in
any case not later than 20 minutes after the end of the test cycle.

After  the  emission  test,  a  zero  gas  and  the  same  span  gas  shall  be  used  for  re-checking  the
analyzers.  The  test  will  be  considered  acceptable  if  the  difference  between  the  pre-test  and
post-test results is less than 2 % of the span gas value.

The particulate filters shall be returned to the weighing chamber no later than one hour after
completion of the test. They  shall  be  conditioned  in  a  petri  dish,  which  is  protected  against
dust  contamination  and  allows  air  exchange,  for  at  least  one  hour,  and  then  weighed.  The
gross weight of the filters shall be recorded.

4.6.

Verification of the test run

4.6.1. Data Shift

To  minimise  the  biasing  effect  of  the  time  lag  between  the  feedback  and  reference  cycle
values,  the  entire  engine  speed  and  torque  feedback  signal  sequence  may  be  advanced  or
delayed  in  time  with  respect  to  the  reference  speed  and  torque  sequence.  If  the  feedback
signals  are  shifted,  both  speed  and  torque  must  be  shifted  the  same  amount  in  the  same
direction.

4.6.2. Calculation of the Cycle Work

The  actual  cycle  work  Wact  (kWh)  shall  be  calculated  using  each  pair  of  engine  feedback
speed and torque values recorded. The actual cycle work Wact is used for comparison to the
reference  cycle  work  Wref  and  for  calculating  the  brake  specific  emissions.  The  same
methodology shall be used for integrating both reference and actual engine power. If values
are  to  be  determined  between  adjacent  reference  or  adjacent  measured  values,  linear
interpolation shall be used.

53

In integrating the reference and actual cycle work, all negative torque values shall be set equal
to zero and included. If integration is performed at a frequency of less than 5 Hertz, and if,
during a given time segment, the torque value changes from positive to negative or negative
to positive, the negative portion shall be computed and set equal to zero. The positive portion
shall be included in the integrated value.

Wact shall be between -15 % and + 5 % of Wref.

4.6.3.

Validation Statistics of the Test Cycle

Linear  regressions  of  the  feedback  values  on  the  reference  values  shall  be  performed  for
speed, torque and power. This shall be done after any feedback data shift has occurred, if this
option is selected. The method of least squares shall be used, with the best fit equation having
the form:

y = mx + b

where:

y

m

x

b

=

=

=

=

feedback (actual) value of speed (min-1) , torque (N·m), or power (kW)

slope of the regression line

reference value of speed (min-1) , torque (N·m), or power (kW)

y intercept of the regression line

The standard error of estimate (SE) of y on x and the coefficient of determination (r²) shall be
calculated for each regression line.

It is recommended that this analysis be performed at 1 Hertz. For a test to be considered valid,
the criteria of Table 1 must be met.

Table 1: Regression Line Tolerances

Speed

Torque

Power

Standard error of estimate (SE) of
Y on X

max 100 min-1 max 13 % of power
map 
maximum
engine torque

max  8%  of  power
map maximum engine
power

Slope of the regression line, m

0,95 to 1,03

0,83 – 1,03

0,89 – 1,03

Coefficient of determination, r²

min 0,9700

min 0,8800

min 0,9100

Y intercept of the regression line,
b

± 50 min-1

±  20  N·m  or  (cid:2)  2  %
torque,
of  max 
whichever is greater

±  4  kW  or  (cid:2)  2  %  of
power,
max 
whichever is greater

For  regression  purposes  only,  point  deletions  are  permitted  where  noted  in  Table  2  before
doing  the  regression  calculation.  However,  those  points  must  not  be  deleted  for  the

54

calculation  of  cycle  work  and  emissions.  An  idle  point  is  defined  as  a  point  having  a
normalized reference torque of 0 % and a normalized reference speed of 0 %. Point deletion
may be applied to the whole or to any part of the cycle.

Table 2. Permitted Point Deletions From Regression Analysis
(points to which the point deletion is applied have to be specified)

CONDITION

SPEED  AND/OR  TORQUE  AND/OR
POWER  POINTS  WHICH  MAY  BE
DELETED  WITH  REFERENCE  TO
THE  CONDITIONS  LISTED  IN  THE
LEFT COLUMN

First 24 (±1) s and last 25 s

Speed, torque and power

Wide open throttle, and torque feedback <
95% torque reference

Torque and/or power

Wide open throttle, and speed feedback <
95% speed reference

Speed and/or power

Closed  throttle,  speed  feedback  >  idle
speed  +  50  min-1,  and  torque  feedback  >
105% torque reference

Closed  throttle,  speed  feedback  (cid:1)  idle
speed  +  50  min-1,  and  torque  feedback  =
idle
Manufacturer 
torque ± 2% of max torque

defined/measured 

Torque and/or power

Speed and/or power

Closed  throttle  and  speed  feedback  >
105% speed reference

Speed and/or power

(e)

Appendix 1 to Annex III is replaced by the following:

APPENDIX 1

MEASUREMENT AND SAMPLING PROCEDURES

1.

MEASUREMENT AND SAMPLING PROCEDURES (NRSC TEST)

Gaseous  and  particulate  components  emitted  by  the  engine  submitted  for  testing  shall  be
measured by the

methods  described  in  Annex  VI.  The  methods  of  Annex  VI  describe  the  recommended
analytical systems for the gaseous emissions (Section 1.1) and the recommended particulate
dilution and sampling systems (Section 1.2).

55

1.1.

Dynamometer specification

An engine dynamometer with adequate characteristics to perform the test cycle described in
Annex III, Section 3.7.1 shall be used. The instrumentation for torque and speed measurement
shall allow the measurement of the power within the given limits. Additional calculations may
be  necessary.  The  accuracy  of  the  measuring  equipment  must  be  such  that  the  maximum
tolerances of the figures given in point 1.3 are not exceeded.

1.2.

Exhaust gas flow

The exhaust gas flow shall be determined by one of the methods mentioned in sections 1.2.1
to 1.2.4.

1.2.1. Direct measurement method

Direct  measurement  of  the  exhaust  flow  by  flow  nozzle  or  equivalent  metering  system  (for
detail see ISO 5167:2000).

Note: Direct gaseous flow measurement is a difficult task. Precautions must be taken to avoid
measurement errors that will impact emission value errors.

1.2.2.

Air and fuel measurement method

Measurement of the airflow and the fuel flow.

Air flow-meters and fuel flow-meters with the accuracy defined in Section 1.3 shall be used.

The calculation of the exhaust gas flow is as follows:

GEXHW = GAIRW + GFUEL (for wet exhaust mass)

1.2.3. Carbon balance method

Exhaust  mass  calculation  from  fuel  consumption  and  exhaust  gas  concentrations  using  the
carbon balance method (see Annex III, Appendix 3).

1.2.4.

Tracer measurement method

The method involves measurement of the concentration of a tracer gas in the exhaust.

A known amount of an inert gas (e.g. pure helium) shall be injected into the exhaust gas flow
as a tracer. The gas is mixed and diluted by the exhaust gas, but must not react in the exhaust
pipe. The concentration of the gas shall then be measured in the exhaust gas sample.

In order to ensure complete mixing of the tracer gas, the exhaust gas sampling probe shall be
located  at  least  1  m  or  30  times  the  diameter  of  the  exhaust  pipe,  whichever  is  larger,
downstream of the tracer gas injection point. The sampling probe may be located closer to the
injection point if complete mixing is verified by comparing the tracer gas concentration with
the reference concentration when the tracer gas is injected upstream of the engine.

The tracer gas flow rate shall be set so that the tracer gas concentration at engine idle speed
after mixing becomes lower than the full scale of the trace gas analyzer.

56

The calculation of the exhaust gas flow is as follows:

G

EXHW

(cid:3)

(cid:2)

60

(cid:2)

(cid:1)

G

T
(cid:1)
conc

EXH
(cid:1)

conc

(cid:2)

a

mix

where

GEXHW =

instantaneous exhaust mass flow, kg/s

GT

=

tracer gas flow, cm³/min

concmix =

instantaneous concentration of the tracer gas after mixing, ppm

(cid:2)EXH

conca

=

=

density of the exhaust gas, kg/m³

background concentration of the tracer gas in the intake air, ppm

The background concentration of the tracer gas (conca) may be determined by averaging the
background concentration measured immediately before the test run and after the test run.

When the background concentration is less than 1% of the concentration of the tracer gas after
mixing (concmix.) at maximum exhaust flow, the background concentration may be neglected.

The total system shall meet the accuracy specifications for the exhaust gas flow, and shall be
calibrated according to Appendix 2, Section 1.11.2

1.2.5.

Air flow and air to fuel ratio measurement method

This  involves  exhaust  mass  calculation  from  the  air  flow  and  the  air  to  fuel  ratio.  The
calculation of the instantaneous exhaust gas mass flow is as follows:

G

EXHW

(cid:9)

G

AIRW

(cid:7)

(cid:6)
(cid:4)
(cid:4)
(cid:5)

(cid:8)

1

1

A/F
st

(cid:7)

(cid:1)

(cid:3)
(cid:1)
(cid:1)
(cid:2)

with

(cid:1)FA

/

st

5,14

(cid:8)
(cid:6)
(cid:6)
(cid:7)

100

-

conc

CO

(cid:1)

10

(cid:1)

4

2

(cid:9)

conc

HC

(cid:1)

10

(cid:1)

4

(cid:1)

(cid:11)

6,9078

(cid:1)
conc

(cid:1)

(cid:2)

(cid:5)
(cid:3)
(cid:3)
(cid:4)

(cid:8)
(cid:6)
(cid:6)
(cid:6)
(cid:6)
(cid:6)
(cid:6)
(cid:7)

45,0

(cid:10)

(cid:9)

1

(cid:1)

2

conc

CO

(cid:1)

10

(cid:1)

4

3,5

(cid:1)

conc

CO2

(cid:2)

1

conc

(cid:1)

10

(cid:1)

4

CO
(cid:1)

3,5

conc

CO2

(cid:1)
conc

(cid:1)

(cid:2)

conc

CO

(cid:1)

10

(cid:1)

4

CO2

(cid:2)

(cid:5)
(cid:3)
(cid:3)
(cid:3)
(cid:3)
(cid:3)
(cid:3)
(cid:4)

(cid:2)4

(cid:2)

conc

CO

CO2

(cid:1)

10

(cid:1)

4

(cid:2)

conc

(cid:1)

(cid:1)

10

HC

57

where A/Fst =

stoichiometric air/fuel ratio, kg/kg

(cid:6)

= relative air / fuel ratio

concCO2 =

dry CO2 concentration, %

concCO =

dry CO concentration, ppm

concHC =

HC concentration, ppm

NOTE: The calculation refers to a diesel fuel with a H/C ratio equal to 1.8

The air flowmeter shall  meet  the  accuracy  specifications  in  Table  3,  the  CO2  analyzer  used
shall  meet  the  specifications  of  clause  1.4.1,  and  the  total  system  shall  meet  the  accuracy
specifications for the exhaust gas flow.

Optionally,  air  to  fuel  ratio  measurement  equipment  such  as  a  zirconia  type  sensor  may  be
used for the measurement of the relative air/fuel ratio in accordance with the specifications of
clause 1.4.4.

1.2.6.

Total dilute exhaust gas flow

When using a full flow dilution system, the total flow of the dilute exhaust (GTOTW) shall be
measured with a PD or CFI or SST - Annex VI, point 1.2.1.2. The accuracy shall conform to
the provisions of Annex III, Appendix 2, Section 2.2.

1.3.

Accuracy

The  calibration  of  all  measurement  instruments  shall  be  traceable  to  national  (international)
standards and comply with the requirements listed in Table 3.

58

Table 3. Accuracy of Measuring Instruments

No. Measuring Instrument

Accuracy

1

 2

3

4

5

6

7

8

9

10

11

12

13

14

Engine speed

(cid:2) 2 % of reading or (cid:2) 1 % of engine's max. value whichever is larger

Torque

(cid:2) 2 % of reading or (cid:2) 1 % of engine's max. value whichever is larger

Fuel consumption

(cid:2) 2 % of engine's max. value

Air consumption

(cid:2) 2 % of reading or (cid:2) 1 % of engine's max. value whichever is larger

Exhaust gas flow

(cid:2) 2,5 % of reading or (cid:2) 1,5 % of engine's max. value whichever is larger

Temperatures (cid:1) 600 K

(cid:2) 2 K absolute

Temperatures > 600 K

(cid:2) 1 % of reading

Exhaust gas pressure

(cid:2) 0,2 kPa absolute

Intake air depression

(cid:2) 0,05 kPa absolute

Atmospheric pressure

(cid:2) 0,1 kPa absolute

Other pressures

(cid:2) 0,1 kPa absolute

Absolute humidity

(cid:2) 5 % of reading

Dilution air flow

(cid:2) 2 % of reading

Diluted exhaust gas flow (cid:2) 2 % of reading

1.4.

Determination of the gaseous components

1.4.1. General analyser specifications

The analysers shall have a measuring range appropriate for the accuracy required to measure
the concentrations of the exhaust gas components (point 1.4.1.1). It is recommended that the
analysers be operated such that the measured concentration falls between 15 % and 100 % of
full scale.

If the full scale value is 155 ppm (or ppm C) or less or if read-out systems (computers, data
loggers)  that  provide  sufficient  accuracy  and  resolution  below  15  %  of  full  scale  are  used
concentrations  below  15  %  of  full  scale  are  also  acceptable.  In  this  case,  additional
calibrations  are  to  be  made  to  ensure  the  accuracy  of  the  calibration  curves  -  Annex  III,
Appendix 2, point 1.5.5.2.

The electromagnetic compatibility (EMC) of the equipment shall be on a level as to minimize
additional errors.

59

1.4.1.1. Measurement error

The analyzer shall not deviate from the nominal calibration point by more than ± 2 % of the
reading or ± 0.3 % of full scale whichever is larger.

NOTE: For the purpose of this standard, accuracy is defined as the deviation of the analyzer
reading from the nominal calibration values using a calibration gas ((cid:7) true value)

1.4.1.2. Repeatability

The repeatability, defined as 2,5 times the standard deviation of 10 repetitive responses to a
given  calibration or span gas, must be no  greater than ± 1  % of full scale concentration for
each range used above 155 ppm (or ppm C) or ± 2 % of each range used below 155 ppm (or
ppm C).

1.4.1.3. Noise

The analyser peak-to-peak response to zero and calibration or span gases over any 10-second
period shall not exceed 2 % of full scale on all ranges used.

1.4.1.4. Zero drift

The zero drift during a one-hour period shall be less than 2 % of full scale on the lowest range
used. The zero response is defined as the mean response, including noise, to a zero gas during
a 30-second time interval.

1.4.1.5. Span drift

The span drift during a one-hour period shall be less than 2 % of full scale on the lowest range
used. Span is defined as the difference between the span response and the zero response. The
span  response  is  defined  as  the  mean  response,  including  noise,  to  a  span  gas  during  a  30-
second time interval.

1.4.2. Gas drying

The  optional  gas  drying  device  must  have  a  minimal  effect  on  the  concentration  of  the
measured gases. Chemical dryers are not an  acceptable method of  removing water from the
sample.

1.4.3.

Analysers

Sections 1.4.3.1. to 1.4.3.5 of this Appendix describe the measurement principles to be used.
A detailed description of the measurement systems is given in Annex VI.

The  gases  to  be  measured  shall  be  analysed  with  the  following  instruments.  For  non-linear
analysers, the use of linearizing circuits is permitted.

1.4.3.1. Carbon monoxide (CO) analysis

The  carbon  monoxide  analyser  shall  be  of  the  non-dispersive  infra-red  (NDIR)  absorption
type.

60

1.4.3.2. Carbon dioxide (CO2) analysis

The carbon dioxide analyser shall be of the non-dispersive infra-red (NDIR) absorption type.

1.4.3.3. Hydrocarbon (HC) analysis

The hydrocarbon analyser shall be of the heated flame ionization detector (HFID) type with
detector, valves, pipework, etc, heated so as to maintain a gas temperature of 463 K (190 °C)
± 10 K.

1.4.3.4. Oxides of nitrogen (NOx) analysis

The oxides of nitrogen  analyser  shall  be  of  the  chemiluminescent  detector  (CLD)  or  heated
chemiluminescent  detector  (HCLD)  type  with  a  NO2/NO  converter,  if  measured  on  a  dry
basis. If measured on a wet basis, a HCLD with converter maintained above 328 K (55 °C)
shall  be  used,  provided  the  water  quench  check  (Annex  III,  Appendix  2,  point  1.9.2.2)  is
satisfied.

For both CLD and HCLD, the sampling path shall be maintained at a wall temperature of 328
K to 473 K ( 55 °C to 200 °C) up to the converter for dry measurement, and up to the analyzer
for wet measurement.

1.4.4.

Air to fuel measurement

The air to fuel measurement equipment used to determine the exhaust gas flow as specified in
clause 1.2.5 shall be a wide range air to fuel ratio sensor or lambda sensor of Zirconia type.

The sensor shall be mounted directly on the exhaust pipe where the exhaust gas temperature is
high enough to eliminate water condensation.

The accuracy of the sensor with incorporated electronics shall be within:

(cid:2) 3 % of reading

(cid:6)

< 2

(cid:2) 5 % of reading

(cid:2) 10 % of reading

2 (cid:1)

5 (cid:1)

(cid:6)

(cid:6)

< 5

To  fulfil  the  accuracy  specified  above,  the  sensor  shall  be  calibrated  as  specified  by  the
instrument manufacturer.

1.4.5.

Sampling for gaseous emissions

The  gaseous  emissions  sampling  probes  must  be  fitted  at  least  0,5  m  or  three  times  the
diameter of the exhaust pipe - whichever is the larger - upstream of the exit of the exhaust gas
system  as  far  as  applicable  and  sufficiently  close  to  the  engine  as  to  ensure  an  exhaust  gas
temperature of at least 343 K (70 °C) at the probe.

In the case of a multi-cylinder engine with a branched exhaust manifold, the inlet of the probe
shall be located sufficiently far downstream so as to ensure that the sample is representative
of the average exhaust emissions from all cylinders. In multi-cylinder engines having distinct
groups  of  manifolds,  such  as  in  a  'V`-engine  configuration,  it  is  permissible  to  acquire  a
sample  from  each  group  individually  and  calculate  an  average  exhaust  emission.  Other

61

methods  which  have  been  shown  to  correlate  with  the  above  methods  may  be  used.  For
exhaust emissions calculation the total exhaust mass flow of the engine must be used.

If the composition of the exhaust gas is influenced by any exhaust after-treatment system, the
exhaust sample must be taken upstream of this device in the tests of stage I and downstream
of  this  device  in  the  tests  of  stage  II.  When  a  full  flow  dilution  system  is  used  for  the
determination of the particulates, the gaseous emissions may also be determined in the diluted
exhaust  gas.  The  sampling  probes  shall  be  close  to  the  particulate  sampling  probe  in  the
dilution  tunnel  (Annex  VI,  point  1.2.1.2,  DT  and  Section  1.2.2,  PSP).  CO  and  CO2  may
optionally  be  determined  by  sampling  into  a  bag  and  subsequent  measurement  of  the
concentration in the sampling bag.

1.5.

Determination of the particulates

The  determination  of  the  particulates  requires  a  dilution  system.  Dilution  may  be
accomplished  by  a  partial  flow  dilution  system  or  a  full  flow  dilution  system.  The  flow
capacity  of  the  dilution  system  shall  be  large  enough  to  completely  eliminate  water
condensation  in  the  dilution  and  sampling  systems,  and  maintain  the  temperature  of  the
diluted  exhaust  gas  between  315  K  (42°C)  and  325  K  (52°C)  immediately  upstream  of  the
filter holders. De-humidifying the dilution air before entering the dilution system is permitted,
if  the  air  humidity  is  high.  Dilution  air  pre-heating  above  the  temperature  limit  of  303  K
(30 °C) is recommended, if the ambient temperature is below 293  K  (20  °C).  However,  the
diluted air temperature must not exceed 325 K (52 °C) prior to the introduction of the exhaust
in the dilution tunnel.

Note: For steady-state procedure, the filter temperature may be kept at or below the maximum
temperature of 325 K (52 °C) instead of respecting the temperature range of 42 °C – 52 °C.

For a partial flow dilution system, the particulate sampling probe must be fitted close to and
upstream of the  gaseous probe  as defined in  Section 4.4  and  in  accordance  with  Annex  VI,
point 1.2.1.1, figure 4-12 EP and SP.

The  partial  flow  dilution  system  has  to  be  designed  to  split  the  exhaust  stream  into  two
fractions,  the  smaller  one  being  diluted  with  air  and  subsequently  used  for  particulate
measurement.  From that it is  essential  that  the  dilution  ratio  be  determined  very  accurately.
Different  splitting  methods  can  be  applied,  whereby  the  type  of  splitting  used  dictates  to  a
significant  degree  the  sampling  hardware  and  procedures  to  be  used  (Annex  VI,  point
1.2.1.1).

To determine the mass of the particulates, a particulate sampling system, particulate sampling
filters, a microgram balance and a temperature and humidity controlled weighing chamber are
required.

For particulate sampling, two methods may be applied:

- the single filter method uses one pair of filters (see point 1.5.1.3. of this Appendix) for all
modes  of  the  test  cycle.  Considerable  attention  must  be  paid  to  sampling  times  and  flows
during the sampling phase of the test. However, only one pair of filters will be required for
the test cycle,

- the multiple filter method dictates that one pair of filters (see point 1.5.1.3. of this Appendix)
is used for each of the individual modes of the test cycle. This method allows more  lenient
sample procedures but uses more filters.

62

1.5.1.

Particulate sampling filters

1.5.1.1. Filter specification

Fluorocarbon coated glass fibre filters or fluorocarbon based membrane filters are required for
certification  tests.  For  special  applications  different  filter  materials  may  be  used.  All  filter
types shall have a 0,3 µm DOP (di-octylphthalate) collection efficiency of at least 99% at a
gas  face  velocity  between  35  and  100  cm/s.  When  performing  correlation  tests  between
laboratories or between a manufacturer and an approval authority, filters of identical quality
must be used.

1.5.1.2. Filter size

Particulate filters must have a minimum diameter of 47 mm (37 mm stain diameter). Larger
diameter filters are acceptable (point 1.5.1.5.).

1.5.1.3. Primary and back-up filters

The diluted exhaust shall be sampled by a pair of filters placed in series (one primary and one
back-up  filter)  during  the  test  sequence.  The  back-up  filter  shall  be  located  no  more  than
100 mm downstream of, and shall not be in contact with the primary filter. The filters may be
weighed separately or as a pair with the filters placed stain side to stain side.

1.5.1.4. Filter face velocity

A gas face velocity through the filter of 35 to 100 cm/s shall be achieved. The pressure drop
increase between the beginning and the end of the test shall be no more than 25 kPa.

1.5.1.5. Filter loading

The recommended minimum filter loadings for the most common filter sizes are shown in the
folowing table. For larger filter sizes, the minimum filter loading shall be 0,065 mg/1000 mm²
filter area.

Filter 
(mm)

Diameter

Recommended  stain  diameter
(mm)

Recommended  minimum  loading
(mg)

47

70

90

110

37

60

80

100

0,11

0,25

0,41

0,62

For  the  multiple  filter  method,  the  recommended  minimum  filter  loading  for  the  sum  of  all
filters  shall  be  the  product  of  the  appropriate  value  above  and  the  square  root  of  the  total
number of modes.

63

1.5.2. Weighing chamber and analytical balance specifications

1.5.2.1. Weighing chamber conditions

The temperature of the chamber (or room) in which the particulate filters are conditioned and
weighed shall be maintained to within 295 K (22 °C) ± 3 K during all filter conditioning and
weighing.  The  humidity  shall  be  maintained  to  a  dew  point  of  282,5  (9,5  °C)  ±  3  K  and  a
relative humidity of 45 ± 8 %.

1.5.2.2. Reference filter weighing

The chamber (or room) environment shall be free of any ambient contaminants (such as dust)
that would settle on the particulate filters during their stabilisation. Disturbances to weighing
room  specifications  as  outlined  in  point  1.5.2.1.  will  be  allowed  if  the  duration  of  the
disturbances  does  not  exceed  30  minutes.  The  weighing  room  should  meet  the  required
specifications  prior  to  personnel  entrance  into  the  weighing  room.  At  least  two  unused
reference filters or reference filter pairs shall be weighed within four hours of, but preferably
at the same time as the sample filter (pair) weighing. They shall be the same size and material
as the sample filters.

If the average weight of the reference filters (reference filter pairs) changes between sample
filter weighing by more than 10(cid:8)g, then all sample filters shall be discarded and the emissions
test repeated.

If the weighing room stability  criteria outlined in point 1.5.2.1 is not met, but the reference
filter  (pair)  weighing  meet  the  above  criteria,  the  engine  manufacturer  has  the  option  of
accepting  the  sample  filter  weights  or  voiding  the  tests,  fixing  the  weighing  room  control
system and re-running the test.

1.5.2.3. Analytical balance

The  analytical  balance  used  to  determine  the  weights  of  all  filters  shall  have  a  precision
(standard deviation) of 2 µg and a resolution of 1 µg (1 digit = 1 µg) specified by the balance
manufacturer.

1.5.2.4. Elimination of static electricity effects

To eliminate the effects of static electricity, the filters shall be neutralized prior to weighing,
for example, by a Polonium neutralizer or a device of similar effect.

1.5.3.

Additional specifications for particulate measurement

All parts of the dilution system and the sampling system from the exhaust pipe up to the filter
holder, which are in contact with raw and diluted exhaust gas, must be designed to minimize
deposition or alteration of the particulates. All parts must be made of electrically conductive
materials that do not react with exhaust gas components, and must be electrically grounded to
prevent electrostatic effects.

64

2.

MEASUREMENT AND SAMPLING PROCEDURES (NRTC TEST)

2.1.

Introduction

Gaseous  and  particulate  components  emitted  by  the  engine  submitted  for  testing  shall  be
measured  by  the  methods  described  in  Annex  VI.  The  methods  of  Annex  VI  describe  the
recommended  analytical  systems  for  the  gaseous  emissions  (Section  1.1)  and  the
recommended particulate dilution and sampling systems (Section 1.2).

2.2.

Dynamometer and test cell equipment

The following equipment shall be used for emission tests of engines on engine dynamometers.

2.2.1.

Engine Dynamometer

An engine dynamometer shall be used with adequate characteristics to perform the test cycle
described  in  Appendix  4  to  this  Annex.  The  instrumentation  for  torque  and  speed
measurement  shall  allow  the  measurement  of  the  power  within  the  given  limits.  Additional
calculations may be necessary. The accuracy of the measuring equipment must be such that
the maximum tolerances of the figures given in Table 3 are not exceeded.

2.2.2. Other Instruments

Measuring  instruments  for  fuel  consumption,  air  consumption,  temperature  of  coolant  and
lubricant, exhaust gas pressure and intake manifold depression, exhaust  gas temperature,  air
intake  temperature,  atmospheric  pressure,  humidity  and  fuel  temperature  shall  be  used,  as
required. These instruments shall satisfy the requirements given in Table 3:

65

Table 3. Accuracy of Measuring Instruments

No. Measuring Instrument

Accuracy

1

2

3

4

5

6

7

8

9

10

11

12

13

14

Engine speed

(cid:2) 2 % of reading or (cid:2) 1 % of engine's max. value whichever is larger

Torque

(cid:2) 2 % of reading or (cid:2) 1 % of engine's max. value whichever is larger

Fuel consumption

(cid:2) 2 % of engine's max. value

Air consumption

(cid:2) 2 % of reading or (cid:2) 1 % of engine's max. value whichever is larger

Exhaust gas flow

(cid:2) 2,5 % of reading or (cid:2) 1,5 % of engine's max. value whichever is larger

Temperatures (cid:1) 600 K

(cid:2) 2 K absolute

Temperatures > 600 K

(cid:2) 1 % of reading

Exhaust gas pressure

(cid:2) 0,2 kPa absolute

Intake air depression

(cid:2) 0,05 kPa absolute

Atmospheric pressure

(cid:2) 0,1 kPa absolute

Other pressures

(cid:2) 0,1 kPa absolute

Absolute humidity

(cid:2) 5 % of reading

Dilution air flow

(cid:2) 2 % of reading

Diluted exhaust gas flow (cid:2) 2 % of reading

2.2.3.

Raw Exhaust Gas Flow

For calculating the emissions in the raw exhaust gas and for controlling a partial flow dilution
system, it is necessary to know the exhaust gas mass flow rate. For determinating the exhaust
mass flow rate, either of the methods described in the following clauses may be used.

For the purpose of emissions calculation, the response time of either method described below
shall  be  equal  to  or  less  than  the  requirement  for  the  analyzer  response  time,  as  defined  in
Appendix 2, Section 1.11.1.

For the purpose of controlling a partial flow dilution system, a faster response is required. For
partial flow dilution systems with online control, a response time of (cid:1) 0,3 s is required. For
partial  flow  dilution  systems  with  look  ahead  control  based  on  a  pre-recorded  test  run,  a
response time of the exhaust flow measurement system of (cid:1) 5 s with a rise time of (cid:1) 1 s is
required.  The  system  response  time  shall  be  specified  by  the  instrument  manufacturer.  The
combined response time requirements for exhaust gas flow  and  partial  flow  dilution  system
are indicated in Section 2.4.

66

Direct measurement method

Direct measurement of the instantaneous exhaust flow may be done by systems, such as:

-

-

-

pressure differential devices, like flow nozzle, (details see ISO 5167: 2000)

ultrasonic flowmeter

vortex flowmeter

Precautions  shall  be  taken  to  avoid  measurement  errors,  which  will  impact  emission  value
errors.  Such  precautions  include  the  careful  installation  of  the  device  in  the  engine  exhaust
system according to the instrument manufacturers' recommendations and to good engineering
practice.  Especially,  engine  performance  and  emissions  must  not  be  affected  by  the
installation of the device.

The flowmeters shall meet the accuracy specifications of Table 3.

Air and fuel measurement method

This  involves  measurement  of  the  airflow  and  the  fuel  flow  with  suitable  flowmeters.  The
calculation of the instantaneous exhaust gas flow is as follows:

GEXHW =

GAIRW + GFUEL (for wet exhaust mass)

The flowmeters shall meet the accuracy specifications of Table 3, but shall also be accurate
enough to also meet the accuracy specifications for the exhaust gas flow.

Tracer measurement method

This involves measurement of the concentration of a tracer gas in the exhaust.

A known amount of an inert gas (e.g. pure helium) shall be injected into the exhaust gas flow
as a tracer. The gas is mixed and diluted by the exhaust gas, but must not react in the exhaust
pipe. The concentration of the gas shall then be measured in the exhaust gas sample.

In order to ensure complete mixing of the tracer gas, the exhaust gas sampling probe shall be
located  at  least  1  m  or  30  times  the  diameter  of  the  exhaust  pipe,  whichever  is  larger,
downstream of the tracer gas injection point. The sampling probe may be located closer to the
injection point if complete mixing is verified by comparing the tracer gas concentration with
the reference concentration when the tracer gas is injected upstream of the engine.

The tracer gas flow rate shall be set so that the tracer gas concentration at engine idle speed
after mixing becomes lower than the full scale of the trace gas analyzer.

The calculation of the exhaust gas flow is as follows:

G

EXHW

(cid:3)

(cid:2)

60

(cid:2)

(cid:1)

G
T
(cid:1)
conc

EXH
(cid:1)

conc
a

(cid:2)

mix

67

where

GEXHW =

instantaneous exhaust mass flow, kg/s

GT

=

tracer gas flow, cm³/min

concmix=

(cid:2)EXH =

conca =

instantaneous concentration of the tracer gas after mixing, ppm

density of the exhaust gas, kg/m³

background concentration of the tracer gas in the intake air, ppm

The background concentration of the tracer gas (conca) may be determined by averaging the
background concentration measured immediately before the test run and after the test run.

When the background concentration is less than 1% of the concentration of the tracer gas after
mixing (concmix.) at maximum exhaust flow, the background concentration may be neglected.

The total system shall meet the accuracy specifications for the exhaust gas flow, and shall be
calibrated according to Appendix 2, paragraph 1.11.2

Air flow and air to fuel ratio measurement method

This  involves  exhaust  mass  calculation  from  the  airflow  and  the  air  to  fuel  ratio.  The
calculation of the instantaneous exhaust gas mass flow is as follows:

G

EXHW

(cid:9)

G

AIRW

(cid:7)

(cid:6)
(cid:4)
(cid:4)
(cid:5)

(cid:8)

1

1

A/F
st

(cid:7)

(cid:1)

(cid:3)
(cid:1)
(cid:1)
(cid:2)

with

(cid:1)FA

/

st

5,14

(cid:8)
(cid:6)
(cid:6)
(cid:7)

100

-

conc

CO

(cid:1)

10

(cid:1)

4

2

(cid:9)

conc

HC

(cid:1)

10

(cid:1)

4

(cid:1)

(cid:11)

6,9078

(cid:1)
conc

(cid:1)

(cid:2)

(cid:5)
(cid:3)
(cid:3)
(cid:4)

(cid:8)
(cid:6)
(cid:6)
(cid:6)
(cid:6)
(cid:6)
(cid:6)
(cid:7)

45,0

(cid:10)

(cid:9)

1

(cid:1)

2

conc

CO

(cid:1)

10

(cid:1)

4

3,5

(cid:1)

conc

CO2

(cid:2)

1

conc

(cid:1)

10

(cid:1)

4

CO
(cid:1)

3,5

conc

CO2

(cid:1)
conc

(cid:1)

(cid:2)

conc

CO

(cid:1)

10

(cid:1)

4

CO2

(cid:2)

(cid:5)
(cid:3)
(cid:3)
(cid:3)
(cid:3)
(cid:3)
(cid:3)
(cid:4)

(cid:2)4

(cid:2)

conc

CO

CO2

(cid:1)

10

(cid:1)

4

(cid:2)

conc

(cid:1)

(cid:1)

10

HC

68

where A/Fst =

stoichiometric air/fuel ratio, kg/kg

(cid:6)

= relative air / fuel ratio

concCO2 =

dry CO2 concentration, %

concCO =

dry CO concentration, ppm

concHC =

HC concentration, ppm

NOTE: The calculation refers to a diesel fuel with a H/C ratio equal to 1.8

The air flowmeter shall  meet  the  accuracy  specifications  in  Table  3,  the  CO2  analyzer  used
shall  meet  the  specifications  of  clause  2.3.1,  and  the  total  system  shall  meet  the  accuracy
specifications for the exhaust gas flow.

Optionally,  air  to  fuel  ratio  measurement  equipment  such  as  a  zirconia  type  sensor  may  be
used  for  the  measurement  of  the  excess  air  ratio  in  accordance  with  the  specifications  of
clause 2.3.4.

2.2.4. Diluted Exhaust Gas Flow

For calculation of the emissions in the diluted exhaust gas, it is necessary to know the diluted
exhaust gas mass flow rate. The total diluted exhaust gas flow over the cycle (kg/test) shall be
calculated from the measurement values over the cycle and the corresponding calibration data
of  the  flow  measurement  device  (V0  for  PDV,  KV  for  CFV,  Cd  for  SSV)  the  corresponding
methods  described  in  Appendix  3,  clause  2.2.1  shall  be  used.  If  the  total  sample  mass  of
particulates and gaseous pollutants exceeds 0,5 % of the total CVS flow, the CVS flow shall
be  corrected  or  the  particulate  sample  flow  shall  be  returned  to  the  CVS  prior  to  the  flow
measuring device.

2.3.

Determination of the gaseous components

2.3.1. General Analyser Specifications

The analysers shall have a measuring range appropriate for the accuracy required to measure
the concentrations of the exhaust gas components (point 1.4.1.1). It is recommended that the
analysers be operated such that the measured concentration falls between 15 % and 100 % of
full scale.

If the full scale value is 155 ppm (or ppm C) or less or if read-out systems (computers, data
loggers)  that  provide  sufficient  accuracy  and  resolution  below  15  %  of  full  scale  are  used
concentrations  below  15  %  of  full  scale  are  also  acceptable.  In  this  case,  additional
calibrations  are  to  be  made  to  ensure  the  accuracy  of  the  calibration  curves  -  Annex  III,
Appendix 2, point 1.5.5.2.

The  electromagnetic  compatibility  (EMC)  of  the  equipment  shall  be  of  a  level  such  as  to
minimize additional errors.

69

2.3.1.1. Measurement error

The analyzer shall not deviate from the nominal calibration point by more than ± 2 % of the
reading or ± 0.3 % of full scale whichever is larger.

NOTE: For the purpose of this standard, accuracy is defined as the deviation of the analyzer
reading from the nominal calibration values using a calibration gas ((cid:7) true value).

2.3.1.2. Repeatability

The repeatability, defined as 2,5 times the standard deviation of 10 repetitive responses to a
given  calibration or span gas, must be no  greater than ± 1  % of full scale concentration for
each range used above 155 ppm (or ppm C) or ± 2 % of each range used below 155 ppm (or
ppm C).

2.3.1.3. Noise

The analyser peak-to-peak response to zero and calibration or span gases over any 10-second
period shall not exceed 2 % of full scale on all ranges used.

2.3.1.4. Zero drift

The zero drift during a one-hour period shall be less than 2 % of full scale on the lowest range
used. The zero response is defined as the mean response, including noise, to a zero gas during
a 30-second time interval.

2.3.1.5. Span drift

The span drift during a one-hour period shall be less than 2 % of full scale on the lowest range
used. Span is defined as the difference between the span response and the zero response. The
span  response  is  defined  as  the  mean  response,  including  noise,  to  a  span  gas  during  a  30-
second time interval.

2.3.1.6. Rise Time

For  raw  exhaust  gas  analysis,  the  rise  time  of  the  analyzer  installed  in  the  measurement
system shall not exceed 2,5 s.

NOTE:  Only  evaluating  the  response  time  of  the  analyzer  alone  will  not  clearly  define  the
suitability  of  the  total  system  for  transient  testing.  Volumes  and  especially  dead  volumes
through  out  the  system  will  not  only  affect  the  transportation  time  from  the  probe  to  the
analyzer,  but  also  affect  the  rise  time.  Also  transport  times  inside  of  an  analyzer  would  be
defined as analyzer response time, like the converter or water traps inside of a NOx analyzers.
The  determination  of  the  total  system  response  time  is  described  in  Appendix  2,  Section
1.11.1.

70

2.3.2. Gas Drying

Same  specifications  as  for  NRSC  test  cycle  apply  (see  previous  Section  1.4.2)  as  described
here below.

The  optional  gas  drying  device  must  have  a  minimal  effect  on  the  concentration  of  the
measured gases. Chemical dryers are not an  acceptable method of removing water from the
sample.

2.3.3.

Analysers

Same  specifications  as  for  NRSC  test  cycle  apply  (see  previous  Section  1.4.3)  as  described
here below.

The  gases  to  be  measured  shall  be  analysed  with  the  following  instruments.  For  non-linear
analysers, the use of linearizing circuits is permitted.

2.3.3.1. Carbon monoxide (CO) analysis

The  carbon  monoxide  analyser  shall  be  of  the  non-dispersive  infra-red  (NDIR)  absorption
type.

2.3.3.2. Carbon dioxide (CO2) analysis

The carbon dioxide analyser shall be of the non-dispersive infra-red (NDIR) absorption type.

2.3.3.3. Hydrocarbon (HC) analysis

The hydrocarbon analyser shall be of the heated flame ionization detector (HFID) type with
detector, valves, pipework, etc, heated so as to maintain a gas temperature of 463 K (190 °C)
± 10 K.

2.3.3.4. Oxides of nitrogen (NOx) analysis

The oxides of nitrogen  analyser  shall  be  of  the  chemiluminescent  detector  (CLD)  or  heated
chemiluminescent  detector  (HCLD)  type  with  a  NO2/NO  converter,  if  measured  on  a  dry
basis.  If measured  on  a  wet  basis,  a  HCLD  with  converter  maintained  above  328  K  (55  °C
shall  be  used,  provided  the  water  quench  check  (Annex  III,  Appendix  2,  point  1.9.2.2)  is
satisfied.

For  both  CLD  and  HCLD,  the  sampling  path  shall  be  maintained  at  a  wall  temperature  of
328 K  to  473  K  (  55°C  to  200°C)  up  to  the  converter  for  dry  measurement,  and  up  to  the
analyzer for wet measurement.

2.3.4.

Air to fuel measurement

The air to fuel measurement equipment used to determine the exhaust gas flow as specified in
clause 2.2.3 shall be a wide range air to fuel ratio sensor or lambda sensor of Zirconia type.

The sensor shall be mounted directly on the exhaust pipe where the exhaust gas temperature is
high enough to eliminate water condensation.

71

The accuracy of the sensor with incorporated electronics shall be within:

(cid:2) 3 % of reading

(cid:6)

< 2

(cid:2) 5 % of reading

(cid:2) 10 % of reading

2 (cid:1)

5 (cid:1)

(cid:6)

(cid:6)

< 5

To  fulfil  the  accuracy  specified  above,  the  sensor  shall  be  calibrated  as  specified  by  the
instrument manufacturer.

2.3.5.

Sampling of Gaseous Emissions

2.3.5.1. Raw exhaust gas flow

For calculation of the emissions in the raw exhaust gas the same specifications as for NRSC
test cycle apply (see previous Section 1.4.4), as described here below.

The  gaseous  emissions  sampling  probes  must  be  fitted  at  least  0,5  m  or  three  times  the
diameter of the exhaust pipe - whichever is the larger - upstream of the exit of the exhaust gas
system  as  far  as  applicable  and  sufficiently  close  to  the  engine  as  to  ensure  an  exhaust  gas
temperature of at least 343 K (70 °C) at the probe.

In the case of a multicylinder engine with a branched exhaust manifold, the inlet of the probe
shall be located sufficiently far downstream so as to ensure that the sample is representative
of the average exhaust emissions from all cylinders. In multicylinder engines having distinct
groups  of  manifolds,  such  as  in  a  'V`-engine  configuration,  it  is  permissible  to  acquire  a
sample  from  each  group  individually  and  calculate  an  average  exhaust  emission.  Other
methods  which  have  been  shown  to  correlate  with  the  above  methods  may  be  used.  For
exhaust emissions calculation the total exhaust mass flow of the engine must be used.

If the composition of the exhaust gas is influenced by any exhaust after-treatment system, the
exhaust sample must be taken upstream of this device in the tests of stage I and downstream
of this device in the tests of stage II.

2.3.5.2. Diluted exhaust gas flow

If a full flow dilution system is used, the following specifications apply.

The exhaust pipe between the engine and the full flow dilution system shall conform to the
requirements of Annex VI.

The  gaseous  emissions  sample  probe(s)  shall  be  installed  in  the  dilution  tunnel  at  a  point
where  the  dilution  air  and  exhaust  gas  are  well  mixed,  and  in  close  proximity  to  the
particulates sampling probe.

Sampling can generally be done in two ways:

-

-

the  pollutants  are  sampled  into  a  sampling  bag  over  the  cycle  and  measured  after
completion of the test;

the pollutants are sampled continuously and integrated over the cycle; this method is
mandatory for HC and NOx.

72

The  background  concentrations  shall  be  sampled  upstream  of  the  dilution  tunnel  into  a
sampling  bag,  and  shall  be  subtracted  from  the  emissions  concentration  according  to
Appendix 3, Section 2.2.3.

2.4.

Determination of the particulates

Determination of the particulates requires a dilution system. Dilution may be accomplished by
a partial flow dilution system or a full flow dilution system. The flow capacity of the dilution
system shall be large enough to completely eliminate water condensation in the dilution and
sampling systems, and maintain the temperature of the diluted exhaust gas between 315 K (42
°C)  and  325  K  (52  °C)  immediately  upstream  of  the  filter  holders.  De-humidifying  the
dilution  air  before  entering  the  dilution  system  is  permitted,  if  the  air  humidity  is  high.
Dilution air pre-heating above the temperature limit of 303 K (30 °C) is recommended if the
ambient temperature is below 293 K (20 °C). However, the diluted air temperature must not
exceed 325 K (52 °C) prior to the introduction of the exhaust in the dilution tunnel.

The particulate sampling probe shall be installed in close proximity to the gaseous emissions
sampling probe, and the installation shall comply with the provisions of Section 2.3.5.

To determine the mass of the particulates, a particulate sampling system, particulate sampling
filters, microgram balance, and a temperature and humidity controlled weighing chamber, are
required.

Partial flow dilution system specifications

The  partial  flow  dilution  system  has  to  be  designed  to  split  the  exhaust  stream  into  two
fractions,  the  smaller  one  being  diluted  with  air  and  subsequently  used  for  particulate
measurement.  For  this  it  is  essential  that  the  dilution  ratio  be  determined  very  accurately.
Different  splitting  methods  can  be  applied,  whereby  the  type  of  splitting  used  dictates  to  a
significant  degree  the  sampling  hardware  and  procedures  to  be  used  (Annex  VI,  point
1.2.1.1).

For  the  control  of  a  partial  flow  dilution  system,  a  fast  system  response  is  required.  The
transformation  time  for  the  system  shall  be  determined  by  the  procedure  described  in
Appendix 2, Section 1.11.1.

If the combined transformation time of the exhaust flow measurement (see previous Section)
and the partial flow system is less than 0,3 s, online control may be used. If the transformation
time exceeds 0,3 s, look ahead control based on a pre-recorded test run must be used. In this
case, the rise time shall be (cid:1) 1 s and the delay time of the combination (cid:1) 10 s.

The  total  system  response  shall  be  designed  as  to  ensure  a  representative  sample  of  the
particulates, GSE, proportional to the exhaust mass flow. To determine the proportionality,  a
regression  analysis  of  GSE  versus  GEXHW  shall  be  conducted  on  a  minimum  5  Hz  data
acquisition rate, and the following criteria shall be met:

-

-

-

The correlation coefficient r2 of the linear regression between GSE and GEXHW shall be
not less than 0,95.

The  standard  error  of  estimate  of  GSE  on  GEXHW  shall  not  exceed  5  %  of  GSE
maximum.

GSE intercept of the regression line shall not exceed (cid:2) 2 % of GSE maximum.

73

Optionally, a pre-test may be run, and the exhaust mass flow signal of the pre-test be used for
controlling  the  sample  flow  into  the  particulate  system  ("look-ahead  control").  Such  a
procedure  is  required  if  the  transformation  time  of  the  particulate  system,  t50,P  or/and  the
transformation time of the exhaust mass flow signal, t50,F are > 0,3 s. A correct control of the
partial dilution system is obtained, if the time trace of GEXHW,pre of the pre-test, which controls
GSE, is shifted by a "look-ahead" time of t50,P + t50,F .

For establishing the correlation between GSE and GEXHW the data taken during the actual test
shall be used, with GEXHW time aligned by t50,F relative to GSE (no contribution from t50,P to the
time  alignment).  That  is,  the  time  shift  between  GEXHW  and  GSE  is  the  difference  in  their
transformation times that were determined in Appendix 2, Section 2.6.

For partial flow dilution systems, the accuracy of the sample flow GSE is of special concern, if
not measured directly, but determined by differential flow measurement:

GSE = GTOTW – GDILW

In this case an accuracy of (cid:2) 2 % for GTOTW and GDILW is not sufficient to guarantee acceptable
accuracies  of  GSE.  If  the  gas  flow  is  determined  by  differential  flow  measurement,  the
maximum error of the difference shall be such that the accuracy of GSE is within (cid:2) 5 % when
the dilution ratio is less than 15. It can be calculated by taking root-mean-square of the errors
of each instrument.

Acceptable accuracies of GSE can be obtained by either of the following methods:

a)

b)

c)

d)

The  absolute  accuracies  of  GTOTW  and  GDILW  are  (cid:2)  0,2  %  which  guarantees  an
accuracy of GSE of (cid:1) 5 % at a dilution ratio of 15. However, greater errors will occur
at higher dilution ratios.

Calibration of GDILW relative to GTOTW is carried out such that the same accuracies for
GSE as in a) are obtained. For the details of such a calibration see clause Appendix 2,
Section 2.6.

The accuracy of GSE is determined indirectly from the accuracy of the dilution ratio
as determined by  a tracer  gas,  e.g.  CO2.  Again,  accuracies  equivalent  to  method  a)
for GSE are required.

The  absolute  accuracy  of  GTOTW  and  GDILW  is  within  (cid:2)  2  %  of  full  scale,  the
maximum error of the difference between GTOTW and GDILW is within 0.2 %, and the
linearity error is within (cid:2) 0.2 % of the highest GTOTW observed during the test.

2.4.1.

Particulate Sampling Filters

2.4.1.1. Filter specification

Fluorocarbon coated glass fibre filters or fluorocarbon based membrane filters are required for
certification  tests.  For  special  applications  different  filter  materials  may  be  used.  All  filter
types shall have a 0,3 µm DOP (di-octylphthalate) collection efficiency of at least 99% at a
gas  face  velocity  between  35  and  100  cm/s.  When  performing  correlation  tests  between
laboratories or between a manufacturer and an approval authority, filters of identical quality
must be used.

74

2.4.1.2. Filter size

Particulate filters must have a minimum diameter of 47 mm (37 mm stain diameter). Larger
diameter filters are acceptable (point 2.4.1.5.).

2.4.1.3. Primary and back-up filters

The diluted exhaust shall be sampled by a pair of filters placed in series (one primary and one
back-up  filter)  during  the  test  sequence.  The  back-up  filter  shall  be  located  no  more  than
100 mm downstream of, and shall not be in contact with, the primary filter. The filters may be
weighed separately or as a pair with the filters placed stain side to stain side.

2.4.1.4. Filter face velocity

A gas face velocity through the filter of 35 to 100 cm/s shall be achieved. The pressure drop
increase between the beginning and the end of the test shall be no more than 25 kPa.

2.4.1.5. Filter loading

The recommended minimum filter loadings for the most common filter sizes are shown in the
loading  shall  be
following 
0,065 mg/1000 mm² filter area.

the  minimum 

filter  sizes, 

table.  For 

larger 

filter 

Filter Diameter

(mm)

47

70

90

110

Recommended  stain  diameter
(mm)

37

60

80

100

Recommended minimum loading

(mg)

0,11

0,25

0,41

0,62

2.4.2. Weighing Chamber and Analytical Balance Specifications

2.4.2.1. Weighing chamber conditions

The temperature of the chamber (or room) in which the particulate filters are conditioned and
weighed shall be maintained to within 295 K (22 °C) ± 3 K during all filter conditioning and
weighing.  The  humidity  shall  be  maintained  to  a  dewpoint  of  282,5  (9,5  °C)  ±  3  K  and  a
relative humidity of 45 ± 8 %.

2.4.2.2. Reference filter weighing

The chamber (or room) environment shall be free of any ambient contaminants (such as dust)
that would settle on the particulate filters during their stabilisation. Disturbances to weighing
room  specifications  as  outlined  in  point  2.4.2.1.  will  be  allowed  if  the  duration  of  the
disturbances  does  not  exceed  30  minutes.  The  weighing  room  should  meet  the  required
specifications  prior  to  personnel  entrance  into  the  weighing  room.  At  least  two  unused

75

reference filters or reference filter pairs shall be weighed within four hours of, but preferably
at the same time as the sample filter (pair) weighing. They shall be the same size and material
as the sample filters.

If the average weight of the reference filters (reference filter pairs) changes between sample
filter weighing by more than 10(cid:8)g, then all sample filters shall be discarded and the emissions
test repeated.

If the weighing room stability criteria outlined in point 2.4.2.1 are not met, but the reference
filter  (pair)  weighing  meet  the  above  criteria,  the  engine  manufacturer  has  the  option  of
accepting  the  sample  filter  weights  or  voiding  the  tests,  fixing  the  weighing  room  control
system and re-running the test.

2.4.2.3. Analytical balance

The  analytical  balance  used  to  determine  the  weights  of  all  filters  shall  have  a  precision
(standard deviation) of 2 µg and a resolution of 1 µg (1 digit = 1 µg) specified by the balance
manufacturer.

2.4.2.4. Elimination of static electricity effects

To eliminate the effects of static electricity, the filters shall be neutralized prior to weighing,
for example, by a Polonium neutralizer or a device having similar effect.

2.4.3.

Additional Specifications for Particulate Measurement

All parts of the dilution system and the sampling system from the exhaust pipe up to the filter
holder, which are in contact with raw and diluted exhaust gas, must be designed to minimize
deposition or alteration of the particulates. All parts must be made of electrically conductive
materials that do not react with exhaust gas components, and must be electrically grounded to
prevent electrostatic effects.

(f)

-

Appendix 2 to Annex III is amended as follows:

A new title is inserted as follows:

APPENDIX 2

CALIBRATION PROCEDURE (NRSC, NRTC1)

-

Paragraph 1.2.2 is amended as follows:

After the current text the following is inserted “This accuracy implies that primary gases used
for blending shall  be  known  to  have  an  accuracy  of  at  least  (cid:2)  1  %,  traceable  to  national  or
international  gas  standards.  The  verification  shall  be  performed  at  between  15  and  50  %  of
full scale for each calibration incorporating a blending device. An additional verification may
be performed using another calibration gas, if the first verification has failed.

Optionally, the blending device may be checked with an instrument which by nature is linear,
e.g. using NO gas with a CLD. The span value of the instrument shall be adjusted with the

1

The  calibration  procedure  is  common  for  both  NRSC  and  NRTC  tests,  with  the  exception  of  the  requirements
specified in Paragraphs 1.11 and 2.6.

76

                                                
span  gas  directly  connected  to  the  instrument.  The  blending  device  shall  be  checked  at  the
used settings and the nominal value shall be compared to the measured concentration of the
instrument. This difference shall in each point be within ± 1% of the nominal value.

Other methods may be used based on good engineering practice and with the prior agreement
of the parties involved.

NOTE: A precision gas divider of accuracy is within (cid:2) 1 %, is recommended for establishing
the accurate analyzer calibration curve. The gas divider shall be calibrated by the instrument
manufacturer.”

-

-

-

in paragraph 1.5.5.1, first sentence, the word five is changed to six and in the third
indent the figure 1% is changed to 0,3%

in paragraph 1.5.5.2, last indent, the figure 1% is changed to 0,3%

the text under paragraph 1.8.3 is replaced by the following:

The oxygen interference check shall be determined when introducing an analyser into service
and after major service intervals.

A range shall be chosen where the oxygen interference check gases will fall within the upper
50 %. The test shall be conducted with the oven temperature set as required.

1.8.3.1. Oxygen interference gases

Oxygen  interference  check  gases  shall  contain  propane  with  350  ppmC  ÷  75  ppmC
hydrocarbon.  The  concentration  value  shall  be  determined  to  calibration  gas  tolerances  by
chromatographic  analysis  of  total  hydrocarbons  plus  impurities  or  by  dynamic  blending.
Nitrogen shall be the predominant diluent with the balance oxygen. Blends required for Diesel
engine testing are:

O2 concentration

Balance

21 (20 to 22)

10 (9 to 11

5 (4 to 6)

Nitrogen

Nitrogen

Nitrogen

1.8.3.2. Procedure

a.

b.

c.

d.

The analyzer shall be zeroed.

The analyzer shall be spanned with the 21 % oxygen blend.

The zero response shall be rechecked. If it has changed more than 0,5 % of full scale
clauses (a) and (b) of this section shall be repeated.

The 5 % and 10 % oxygen interference check gases shall be introduced.

77

e.

f.

g.

h.

i.

j.

-

The zero response shall be rechecked. If it has changed more than ± 1 % of full scale,
the test shall be repeated.

The  oxygen  interference  (%O2I)  shall  be  calculated  for  each  mixture  in  step  d)  as
follows:

IO
2

(cid:3)

(cid:2)

(cid:1)

(cid:2)
CB
B

(cid:1)

100

A = hydrocarbon concentration (ppmC) of the span gas used in b) of this subclause

B = hydrocarbon concentration (ppmC) of the oxygen interference check gases used

in d) of this subclause

C = analyzer response

(cid:1)

ppmC (cid:1)

(cid:2)

A
D

D = percent of full scale analyzer response due to A

The  %  of  oxygen  interference  (%O2I)  shall  be  less  than  ±  3,0  %  for  all  required
oxygen interference check gases prior to testing.

If the oxygen interference is greater than ± 3,0 %, the air flow above and below the
manufacturer's specifications shall be incrementally adjusted, repeating clause 1.8.1
for each flow.

If the oxygen interference is greater than ± 3,0 % after adjusting the air flow, the fuel
flow and thereafter the sample flow shall be varied, repeating clause 1.8.1 for  each
new setting.

If  the  oxygen  interference  is  still  greater  than  ±  3,0  %,  the  analyzer,  FID  fuel,  or
burner  air  shall  be  repaired  or  replaced  prior  to  testing.  This  clause  shall  then  be
repeated with the repaired or replaced equipment or gases.

Current paragraph 1.9.2.2 is changed as follows:

(i) Sentence 5 in the first indent is replaced by the following:

The water temperature shall be determined and recorded as F.

(ii) The third indent is replaced by the following:

and recorded as De. For diesel exhaust, the maximum exhaust water vapour concentration (in
%) expected during testing shall be estimated, under the assumption of a fuel atom H/C ratio
of 1,8 to 1, from  the  maximum  CO2  concentration  in  the  exhaust  gas  or  from  the  undiluted
CO2 span gas concentration (A, as measured in section 1.9.2.1) as follows:

-

a new paragraph 1.11. is inserted as follows:

78

1.11.

Additional  calibration  requirements  for  raw  exhaust  measurements  over
NRTC test

1.11.1. Response time check of the analytical system

The  system  settings  for  the  response  time  evaluation  shall  be  exactly  the  same  as  during
measurement of the test run (i.e. pressure, flow rates, filter settings on the analyzers  and all
other  response  time  influences).  The  response  time  determination  shall  be  done  with  gas
switching  directly  at  the  inlet  of  the  sample  probe.  The  gas  switching  shall  be  done  in  less
than  0.1  second.  The  gases  used  for  the  test  shall  cause  a  concentration  change  of  at  least
60% FS.

The concentration trace of each single gas component shall be recorded. The response time is
defined as the difference in time between the gas switching and the appropriate change of the
recorded  concentration.  The  system  response  time  (t90)  consists  of  the  delay  time  to  the
measuring  detector  and  the  rise  time  of  the  detector.  The  delay  time  is  defined  as  the  time
from  the  change  (t0)  until  the  response  is  10%  of  the  final  reading  (t10).  The  rise  time  is
defined as the time between 10% and 90% response of the final reading (t90 – t10).

For time alignment of the analyzer and exhaust flow signals in the case of raw measurement,
the transformation time is defined as the time from the change (t0) until the response is 50%
of the final reading (t50).

The system response time shall be (cid:1) 10 seconds with a rise time (cid:1) 2,5 seconds for all limited
components (CO, NOx, HC) and all ranges used.

1.11.2. Calibration of tracer gas analyzer for exhaust flow measurement

The  analyzer  for  measurement  of  the  tracer  gas  concentration,  if  used,  shall  be  calibrated
using the standard gas.

The  calibration  curve  shall  be  established  by  at  least  10  calibration  points  (excluding  zero)
spaced so that a half of the calibration points are placed between 4% to 20% of analyzer’s full
scale  and  the  rest  are  in  between  20%  to  100%  of  the  full  scale.  The  calibration  curve  is
calculated by the method of least squares.

The calibration curve shall not differ by more than (cid:2) 1% of the full scale from the nominal
value of each calibration point, in the range from 20% to 100% of the full scale. It shall also
not differ by more than (cid:2) 2% from the nominal value in the range from 4% to 20% of the full
scale.

The analyzer shall be set at zero and spanned prior to the test run using a zero gas and a span
gas whose nominal value is more than 80% of the analyzer full scale.

-

the text under paragraph 2.2 is replaced by the following:

The calibration of gas flow-meters or flow measurement instrumentation shall be traceable to
national and/or international standards.

The maximum error of the measured value shall be within ± 2 % of reading.

79

For partial flow dilution systems, the accuracy of the sample flow GSE is of special concern, if
not measured directly, but determined by differential flow measurement:

GSE = GTOTW – GDILW

In this case an accuracy of (cid:2) 2 % for GTOTW and GDILW is not sufficient to guarantee acceptable
accuracies  of  GSE.  If  the  gas  flow  is  determined  by  differential  flow  measurement,  the
maximum error of the difference shall be such that the accuracy of GSE is within (cid:2) 5 % when
the dilution ratio is less than 15. It can be calculated by taking root-mean-square of the errors
of each instrument.

-

a new section 2.6 is inserted as follows:

2.6.

Additional calibration requirements for partial flow dilution systems

2.6.1.

Periodical calibration

If the sample gas flow is determined by differential flow measurement the flow meter or the
flow  measurement  instrumentation  shall  be  calibrated  by  one  of  the  following  procedures,
such that the probe flow GSE into the tunnel fulfils the accuracy requirements of Appendix I
section 2.4:

The flow meter for GDILW is connected in series to the flow meter for GTOTW, the difference
between the  two  flow  meters  is  calibrated  for  at  least  5  set  points  with  flow  values  equally
spaced  between  the  lowest  GDILW  value  used  during  the  test  and  the  value  of  GTOTW  used
during the test The dilution tunnel may be bypassed.

A  calibrated  mass  flow  device  is  connected  in  series  to  the  flowmeter  for  GTOTW  and  the
accuracy is checked for the value used  for the test. Then the calibrated mass flow device is
connected  in  series  to  the  flow  meter  for  GDILW,  and  the  accuracy  is  checked  for  at  least  5
settings corresponding to the dilution ratio between 3  and 50, relative to  GTOTW used during
the test.

The  transfer  tube  TT  is  disconnected  from  the  exhaust,  and  a  calibrated  flow  measuring
device with a suitable range to measure GSE is connected to the transfer tube. Then GTOTW is
set  to  the  value  used  during  the  test,  and  GDILW  is  sequentially  set  to  at  least  5  values
corresponding to dilution ratios q between 3 and 50. Alternatively, a special calibration flow
path,  may  be  provided,  in  which  the  tunnel  is  bypassed,  but  the  total  and  dilution  air  flow
through the corresponding meters as in the actual test.

A  tracer  gas,  is  fed  into  the  transfer  tube  TT.  This  tracer  gas  may  be  a  component  of  the
exhaust  gas,  like  CO2  or  NOx.  After  dilution  in  the  tunnel  the  tracer  gas  component  is
measured. This shall be carried out for 5 dilution ratios between 3 and 50. The accuracy of the
sample flow is determined from the dilution ration q:

GSE = GTOTW /q

The accuracies of the gas analyzers shall be taken into account to guarantee the accuracy of
GSE

80

2.6.2. Carbon flow check

A  carbon  flow  check  using  actual  exhaust  is  strongly  recommended  for  detecting
measurement  and  control  problems  and  verifying  the  proper  operation  of  the  partial  flow
dilution  system.  The  carbon  flow  check  should  be  run  at  least  each  time  a  new  engine  is
installed, or something significant is changed in the test cell configuration.

The  engine  shall  be  operated  at  peak  torque  load  and  speed  or  any  other  steady-state  mode
that produces 5% or more of CO2. The partial flow sampling system shall be operated with a
dilution factor of about 15 to 1.

2.6.3.

Pre-test check

A pre-test check shall be performed within 2 hours before the test run in the following way:

The accuracy of the flow meters shall be checked by the same method as used for calibration
for  at  least  two  points,  including  flow  values  of  GDILW  that  correspond  to  dilution  ratios
between 5 and 15 for the GTOTW value used during the test.

If it can be demonstrated by records of the calibration procedure described above that the flow
meter calibration is stable over a longer period of time, the pre-test check may be omitted.

2.6.4. Determination of the transformation time

The system settings for the transformation time evaluation shall be exactly the same as during
measrement  of  the  test  run.  The  transformation  time  shall  be  determined  by  the  following
method:

An independent reference flowmeter with a measurement range appropriate for the probe flow
shall  be  put  in  series  with  and  closely  coupled  to  the  probe.  This  flowmeter  shall  have  a
transformation  time  of  less  than  100  ms  for  the  flow  step  size  used  in  the  response  time
measurement, with flow restriction sufficiently low not to affect the dynamic performance of
the partial flow dilution system, and consistent with good engineering practice.

A  step  change  shall  be  introduced  to  the  exhaust  flow  (or  air  flow  if  exhaust  flow  is
calculated) input of the partial flow dilution system, from a low flow to at least 90% of full
scale. The trigger for the step change should be the same one as that used to start the look-
ahead  control  in  actual  testing.  The  exhaust  flow  step  stimulus  and  the  flowmeter  response
shall be recorded at a sample rate of at least 10 Hz.

From  this  data,  the  transformation  time  shall  be  determined  for  the  partial  flow  dilution
system,  which  is  the  time  from  the  initiation  of  the  step  stimulus  to  the  50%  point  of  the
flowmeter  response.  In  a  similar  manner,  the  transformation  times  of  the  GSE  signal  of  the
partial  flow  dilution  system  and  of  the  GEXHW  signal  of  the  exhaust  flow  meter  shall  be
determined.  These  signals  are  used  in  the  regression  checks  performed  after  each  test  (see
Appendix I section 2.4).

The calculation shall be repeated for at least  5  rise  and  fall  stimuli,  and  the  results  shall  be
averaged.  The  internal  transformation  time  (<100  ms)  of  the  reference  flowmeter  shall  be
subtracted from this value. This is the “look-ahead” value of the partial flow dilution system,
which shall be applied in accordance with Appendix I section 2.4.

-

a new section 3 is inserted as follows:

81

3.

CALIBRATION OF THE CVS SYSTEM

3.1.

General

The  CVS  system  shall  be  calibrated  by  using  an  accurate  flowmeter  and  means  to  change
operating conditions.

The flow through the system shall be measured  at different flow operating settings,  and the
control parameters of the system shall be measured and related to the flow.

Various type of flowmeters may be used, e.g. calibrated venturi, calibrated laminar flowmeter,
calibrated turbinemeter.

3.2.

Calibration of the Positive Displacement Pump (PD)

All  the  parameters  related  to  the  pump  shall  be  simultaneously  measured  along  with  the
parameters  related  to  a  calibration  venturi  which  is  connected  in  series  with  the  pump.  The
calculated  flow  rate  (in  m3/min  at  pump  inlet,  absolute  pressure  and  temperature)  shall  be
plotted  against  a  correlation  function  which  is  the  value  of  a  specific  combination  of  pump
parameters. The linear equation which relates the pump flow and the correlation function shall
be  determined.  If  a  CVS  has  a  multiple  speed  drive,  the  calibration  shall  be  performed  for
each range used.

Temperature stability shall be maintained during calibration.

Leaks in all the connections and ducting between the calibration venturi and the CVS pump
shall be maintained lower than 0.3% of the lowest flow point (highest restriction and lowest
PD speed point).

3.2.1. Data Analysis

The  air  flowrate  (Qs)  at  each  restriction  setting  (minimum  6  settings)  shall  be  calculated  in
standard m3/min from the flowmeter data using the manufacturer's prescribed method. The air
flow  rate  shall  then  be  converted  to  pump  flow  (V0)  in  m3/rev  at  absolute  pump  inlet
temperature and pressure as follows:

(cid:2)

V
0

Q

s
n

(cid:1)

T
273

(cid:1)

3.101
p

A

where,

Qs

T

pA

n

= air flow rate at standard conditions (101,3 kPa, 273 K), m3/s

= temperature at pump inlet, K

= absolute pressure at pump inlet (pB- p1), kPa

= pump speed, rev/s

To account for the interaction of pressure variations at the pump and the pump slip rate, the
correlation function (X0) between pump speed, pressure differential from pump inlet to pump
outlet and absolute pump outlet pressure shall be calculated as follows:

82

X

0

(cid:2)(cid:3) 1
n

(cid:1)
p

p

p

A

where,

pp(cid:1)

 = pressure differential from pump inlet to pump outlet, kPa

pA = absolute outlet pressure at pump outlet, kPa

A linear least-square fit shall be performed to generate the calibration equation as follows:

V
0

(cid:3)

D
0

(cid:2)

(cid:1)
Xm
(

)

0

D0 and m are the intercept and slope constants, respectively, describing the regression lines.

For  a  CVS  system  with  multiple  speeds,  the  calibration  curves  generated  for  the  different
pump flow ranges shall be approximately parallel, and the intercept values (D0) shall increase
as the pump flow range decreases.

The values calculated by the equation shall be within ± 0,5 % of the measured value of V0.
Values of m will vary from one pump to another. Particulate influx over time will cause the
pump  slip  to  decrease,  as  reflected  by  lower  values  for  m.  Therefore,  calibration  shall  be
performed  at  pump  start-up,  after  major  maintenance,  and  if  the  total  system  verification
(section 3.5) indicates a change in the slip rate.

3.3.

Calibration of the Critical Flow Venturi (CFI)

Calibration  of  the  CFI  is  based  upon  the  flow  equation  for  a  critical  venturi.  Gas  flow  is  a
function of inlet pressure and temperature, as shown below

(cid:2)

Q
s

(cid:1)
pK
v
T

A

where,

Kv = calibration coefficient

pA = absolute pressure at venturi inlet, kPa

T = temperature at venturi inlet, K

83

3.3.1. Data Analysis

The air flow rate (Qs) at each restriction setting (minimum 8 settings) shall be calculated in
standard  m3/min  from  the  flowmeter  data  using  the  manufacturer's  prescribed  method.  The
calibration coefficient shall be calculated from the calibration data for each setting as follows:

(cid:2)

K

v

(cid:1)

Q
S

T

p

A

where,

Qs = air flow rate at standard conditions (101,3 kPa, 273 K), m3/s

T = temperature at the venturi inlet, K

pA = absolute pressure at venturi inlet, kPa

To  determine  the  range  of  critical  flow,  Kv  shall  be  plotted  as  a  function  of  venturi  inlet
pressure.  For  critical  (choked)  flow,  Kv  will  have  a  relatively  constant  value.  As  pressure
decreases  (vacuum  increases),  the  venturi  becomes  unchoked  and  Kv  decreases,  which
indicates that the CFI is operated outside the permissible range.

For a minimum of eight points in the region of critical flow, the average KV and the standard
deviation shall be calculated. The standard deviation shall not exceed ± 0,3 % of the average
KV

3.4.

Calibration of the Subsonic Venturi (SST)

Calibration of the SST is based upon the flow equation for a subsonic venturi. Gas flow is a
function of inlet pressure and temperature, pressure drop between the SST inlet and throat, as
shown below:

Q

SSV

(cid:14)

2
PCdA

d

0

(cid:1)
r

(cid:6)
(cid:4)
(cid:4)
(cid:5)

1

T

A

.1

4286

(cid:13)

r

.1

7143

(cid:12)
(cid:2)
(cid:10)
(cid:10)
(cid:11)

1

(cid:13)

(cid:1)

1

4

r

.1

4286

(cid:9)
(cid:7)
(cid:7)
(cid:8)

(cid:3)
(cid:1)
(cid:1)
(cid:2)

where,

A0

= collection of constants and units conversions

(cid:6)
(cid:4)(cid:4)
(cid:5)

3

m
min

(cid:6)
(cid:4)
(cid:3)
(cid:1)(cid:1)
(cid:4)
(cid:2)
(cid:4)
(cid:5)

1

2

K
kPa

(cid:3)
(cid:1)
(cid:6)
(cid:4)
(cid:1)
(cid:5)
(cid:1)
(cid:2)

1
mm

2

(cid:3)
(cid:1)
(cid:2)

= 0,006111 in SI units of 

d

Cd

PA

T

= diameter of the SST throat, m

= discharge coefficient of the SST

= absolute pressure at venturi inlet, kPa

= temperature at the venturi inlet, K

84

r

ß

= ratio of the SST throat to inlet absolute, static pressure = 

(cid:2)1

P(cid:1)
AP

= ratio of the SST throat diameter, d, to the inlet pipe inner diameter = 

d
D

3.4.1. Data Analysis

The  air  flow  rate  (QSSV)  at  each  flow  setting  (minimum  16  settings)  shall  be  calculated  in
standard  m3/min  from  the  flowmeter  data  using  the  manufacturer's  prescribed  method.  The
discharge coefficient shall be calculated from the calibration data for each setting as follows:

C

d

(cid:14)

Q

SSV

(cid:1)
r

(cid:6)
(cid:4)
(cid:4)
(cid:5)

1

T

A

.1

4286

.1

7143

(cid:13)

r

(cid:12)
(cid:2)
(cid:10)
(cid:10)
(cid:11)

1

(cid:13)

(cid:1)

1

4

r

.1

4286

(cid:9)
(cid:7)
(cid:7)
(cid:8)

(cid:3)
(cid:1)
(cid:1)
(cid:2)

PdA

2

0

where,

QSSV = air flow rate at standard conditions (101,3 kPa, 273 K), m3/s

T

d

r

ß

= temperature at the venturi inlet, K

= diameter of the SST throat, m

= ratio of the SSV throat to inlet absolute, static pressure = 

(cid:2)1

P(cid:1)
AP

= ratio of the SSV throat diameter, d, to the inlet pipe inner diameter = 

d
D

To  determine  the  range  of  subsonic  flow,  Cd  shall  be  plotted  as  a  function  of  Reynolds
number, at the SSV throat. The Re at the SSV throat is calculated with the following formula:

Re (cid:3)

Q
A SSV
(cid:1)d
1

where,

A1

= a collection of constants and units conversions

= 25,55152 

(cid:6)
(cid:4)
(cid:5)

1
3
m

(cid:3)
(cid:1)
(cid:2)

(cid:6)
(cid:4)
(cid:5)

min
s

(cid:3)
(cid:6)
(cid:4)
(cid:1)
(cid:2)
(cid:5)

mm
m

(cid:3)
(cid:1)
(cid:2)

QSSV = air flow rate at standard conditions (101,3 kPa, 273 K), m3/s

d

µ

= diameter of the SSV throat, m

= absolute or dynamic viscosity of the gas, calculated with the following formula:

85

(cid:1)

(cid:2)

3

2

bT
(cid:1)
TS

(cid:2)

bT

(cid:1)

1

1

2

S
T

kg/m-s

where:

b

S

,1

458

(cid:1)

610

kg

1

2

msK

= empirical constant =.

= empirical constant = 

K4,110

Because QSSV is an input to  the  Re  formula,  the  calculations  must  be  started  with  an  initial
guess  for  QSSV  or  Cd  of  the  calibration  venturi,  and  repeated  until  QSSV  converges.  The
convergence method must be accurate to 0.1% or better.

For a minimum of sixteen points in the subsonic flow region, the calculated values of Cd from
the resulting calibration curve fit equation must be within ± 0.5% of the measured Cd for each
calibration point.

3.5.

Total System Verification

The total accuracy of the CVS sampling system and analytical system shall be determined by
introducing a known mass of a pollutant gas into the system while it is being operated in the
normal  manner.  The  pollutant  is  analysed,  and  the  mass  calculated  according  to  Annex  III,
Appendix 3, section 2.4.1 except in the case of propane where a factor of 0,000472 is used in
place of 0,000479 for HC. Either of the following two techniques shall be used.

3.5.1. Metering with a Critical Flow Orifice

A known quantity of pure gas (propane) shall be fed into the CVS system through a calibrated
critical orifice. If the inlet pressure is high enough, the flow rate, which is adjusted by means
of  the  critical  flow  orifice,  is  independent  of  the  orifice  outlet  pressure  (critical  flow).  The
CVS system shall be operated as in a normal exhaust emission test for about 5 to 10 minutes.
A  gas  sample  shall  be  analysed  with  the  usual  equipment  (sampling  bag  or  integrating
method), and the mass of the gas calculated. The mass so determined shall be within ± 3% of
the known mass of the gas injected.

3.5.2. Metering by Means of a Gravimetric Technique

The weight of a small cylinder filled with propane shall be determined with a precision of ±
0,01 g. For about 5 to 10 minutes, the CVS system shall be operated as in a normal exhaust
emission test, while carbon monoxide or propane is injected into the system. The quantity of
pure  gas  discharged  shall  be  determined  by  means  of  differential  weighing.  A  gas  sample
shall  be  analysed  with  the  usual  equipment  (sampling  bag  or  integrating  method),  and  the
mass of the gas calculated. The mass so determined shall be within ± 3% of the known mass
of the gas injected.

86

(g)

Appendix 3 is amended as follows:

-

-

-

-

-

following 

The 
CALCULATIONS”

title 

is 

inserted 

“DATA  EVALUATION  AND

title  of 

the 
shall 
CALCULATIONS – NRSC TEST

section  1 

read  “DATA  EVALUATION  AND

in  paragraph  1.2,  first  sentence,  the  words  “or  volumes  (VSAM,I)”  are  deleted
and in the last indent the words “or volume (VDIL)” and the words “or Md./Vdil”
are deleted

in paragraph 1.3.1, first indent the words “VEXHW or VEXHD0 are deleted and in
the second indent the word VTOTW) are deleted

paragraphs 1.3.2 -1.4.6 are replaced by the following:

1.3.2. Dry/wet correction

When applying GEXHW the measured concentration shall be converted to a wet basis according
to the following formulae, if not already measured on a wet basis:

conc (wet) = kw × conc (dry)

For the raw exhaust gas:

K

,
rW

1,

(cid:9)

(cid:6)
(cid:4)
(cid:4)
(cid:5)

(cid:7)

88,11

(cid:8)

,0

005

(cid:8)

(cid:1)
%

CO

(cid:1)
dry

(cid:2)

(cid:7)

%

CO

2

(cid:1)
dry

(cid:2)
(cid:2)

(cid:7)

K

w

2

1

(cid:3)
(cid:1)
(cid:1)
(cid:2)

K

,
eW

1,

(cid:9)

(cid:7)
(cid:5)
(cid:5)
(cid:6)

(cid:1)

1

88,1

(cid:8)

CO

2

%(

wet

)

200

(cid:4)
(cid:2)
(cid:1)(cid:2)
(cid:3)

K

W

1

K

,
eW

1,

(cid:10)

(cid:6)
(cid:4)
(cid:4)
(cid:4)
(cid:4)(cid:4)
(cid:5)

(cid:8)

1

(cid:9)

1

88,1

(cid:7)

(cid:3)
(cid:1)
(cid:1)
(cid:1)
(cid:1)(cid:1)
(cid:2)

%(

dry

)

1

K

W
CO

2
200

For the diluted gas:

or:

For the dilution air:

DF

(cid:1)
(cid:2)(cid:1)
/11
(cid:1)
(cid:2)(cid:1)
/11

(cid:2)

(cid:4)

DF

H
(cid:2)

a
(cid:4)

(cid:1)

(cid:1)
/1

(cid:1)

H

a

DF
(cid:1)
/1

(cid:2)
(cid:2)

(cid:2)
(cid:2)

DF

(cid:2)(cid:3)
1

k

1
W
608,1

(cid:1)

(cid:1)
H

1000

(cid:4)

608,1
(cid:1)

R

d

22,6

d
(cid:1)

(cid:1)
H
(cid:1)

p

d

d

k

k

,
dW

W

1

H

d

(cid:3)

(cid:3)

p

B

(cid:2)

p

d

(cid:1)

R

d

(cid:1)

10

(cid:1)

2

87

For the intake air (if different from the dilution air):

k

k

(cid:2)(cid:3)
1

,
aW

k

(cid:3)

W

2

1000

(cid:1)

2
W
608,1
(cid:1)
(cid:4)
608,1
(cid:1)
(cid:1)

H
a
(cid:1)

(cid:2)

H

a

(cid:3)

H

a

p

B

22,6
(cid:2)

p

a

R
(cid:1)

a
R

a

p
(cid:1)

a
10

(cid:1)

2

where:

Ha: absolute humidity of the intake air, g water per kg dry air

Hd: absolute humidity of the dilution air, g water per kg dry air

Rd: relative humidity of the dilution air, %

Ra: relative humidity of the intake air, %

pd: saturation vapour pressure of the dilution air, kPa

pa: saturation vapour pressure of the intake air, kPa

pB: total barometric pressure, kPa.

Note: Ha and Hd may be derived from relative humidity measurement, as described above, or
from  dewpoint  measurement,  vapour  pressure  measurement  or  dry/wet  bulb  measurement
using the generally accepted formulae.

1.3.3. Humidity correction for NOx

As  the  NOx  emission  depends  on  ambient  air  conditions,  the  NOx  concentration  shall  be
corrected for ambient air temperature and humidity by the factors KH given in the following
formula:

k

H =

-1

0,0182

(cid:1)

(cid:2)

H

a

(cid:1)

1
(cid:2)
10,71

(cid:3)

0,0045

(cid:1)
T

(cid:2)

a

(cid:2)

(cid:1)

298

where:

Ta: temperatures of the air in K

Ha: humidity of the intake air, g water per kg dry air:

(cid:3)

H

a

p

220
,6
(cid:2)

p

a

B

(cid:1)

(cid:1)

R

a
R

a

(cid:1)

(cid:1)

p

a
10

(cid:1)

2

Ra: relative humidity of the intake air, %

pa: saturation vapour pressure of the intake air, kPa

pB: total barometric pressure, kPa.

88

Note:  Ha  may  be  derived  from  relative  humidity  measurement,  as  described  above,  or  from
dewpoint measurement, vapour pressure measurement or dry/wet bulb measurement using the
generally accepted formulae.

1.3.4. Calculation of emission mass flow rates

The emission mass flow rates for each mode shall be calculated as follows:

(a)

For the raw exhaust gas1:

Gasmass = u × conc × GEXHW

(b)

For the dilute exhaust gas1:

Gasmass = u × concc × GTOTW

where:

concc is the background corrected concentration

conc

DF

c
(cid:3)

(cid:3)

(cid:4)

conc
(cid:1)
conc

/4,13

conc

d

CO

2

(cid:2)
(cid:2)

(cid:1)
/1

(cid:1)
(cid:4)(cid:1)
1
(cid:1)
conc

(cid:2)

CO

DF
(cid:2)

conc

(cid:2)

(cid:1)

10

(cid:1)

(cid:2)4

HC

or:

DF=13,4/concCO2

The coefficients u - wet shall be used according to the following Table 4:

Table  4.  Values  of 

the  coefficients  u 

-  wet 

for  various  exhaust  components

Gas

NOx

CO

HC

CO2

u

0,001587

0,000966

0,000479

conc

ppm

ppm

ppm

15,19

percent

The density of HC is based upon an average carbon to hydrogen ratio of 1:1,85.

1

In  the  case  of  NOx,  the  NOx  concentration  (NOxconc  or  NOxconcc)  has  to  be  multiplied  by  KHNOx  (humidity
correction factor for NOx quoted in the previous section 1.3.3) as follows: KHNOx x conc or KHNOx x concc

89

                                                
1.3.5. Calculation of the specific emissions

The  specific  emission  (g/kWh)  shall  be  calculated  for  all  individual  components  in  the
following way:

Individual

gas

(cid:2)

n

(cid:1)

(cid:1)

1

i

Gas

mass

i

(cid:1)

WF

i

n

(cid:1)

(cid:1)

1

i

P
i

(cid:1)

WF

i

where Pi = Pm,i + PAE,i.

The  weighting  factors  and  the  number  of  modes  (n)  used  in  the  above  calculation  are
according to Annex III, section 3.7.1.

1.4.

Calculation of the particulate emission

The particulate emission shall be calculated in the following way:

1.4.1. Humidity correction factor for particulates

As  the  particulate  emission  of  diesel  engines  depends  on  ambient  air  conditions,  the
particulate mass flow rate shall be corrected for ambient air humidity with the factor Kp given
in the following formula:

K

P

(cid:4)

(cid:1)
1/1

(cid:3)

,0

0133

(cid:1)

(cid:2)

H

a

(cid:1)

(cid:2)71,10
(cid:2)

Ha: humidity of the intake air, gram of water per kg dry air

(cid:3)

H

a

p

,6
220
(cid:2)

p

a

B

(cid:1)

(cid:1)

R

a
R

a

(cid:1)

(cid:1)

p

a
10

(cid:1)

2

Ra: relative humidity of the intake air,%

pa: saturation vapour pressure of the intake air, kPa

pB: total barometric pressure, kPa

Note:  Ha  may  be  derived  from  relative  humidity  measurement,  as  described  above,  or  from
dewpoint measurement, vapour pressure measurement or dry/wet bulb measurement using the
generally accepted formulae

1.4.2.

Partial flow dilution system

The  final  reported  test  results  of  the  particulate  emission  shall  be  derived  through  the
following steps. Since various types of dilution rate control may be used, different calculation
methods for equivalent diluted exhaust gas mass flow rate GEDF apply. All calculations shall
be based upon the average values of the individual modes (i) during the sampling period.

90

1.4.2.1. Isokinetic systems

GEDFW,i = GEXHW,i × qi

G

(cid:3)

q

i

DILW

,
i
(cid:1)
G

(cid:1)
G

(cid:2)

EXHW

,

i

,

EXHW
(cid:1)

(cid:2)r

i

(cid:2)

(cid:1)

r

where  r  corresponds  to  the  ratio  of  the  cross  sectional  areas  of  the  isokinetic  probe  Ap  and
exhaust pipe AT:

r (cid:1)

A
P
A
T

1.4.2.2. Systems with measurement of CO2 or NOx concentration

GEDFW,i = GEXHW,i × qi

(cid:2)

q

i

Conc

,
iE

Conc

,
iD

(cid:1)

(cid:1)

Conc

Conc

,
iA

,
iA

where:

ConcE = wet concentration of the tracer gas in raw exhaust

ConcD = wet concentration of the tracer gas in the diluted exhaust

ConcA = wet concentration of the tracer gas in the dilution air

Concentrations measured on a dry basis shall be converted to a wet basis according to section
1.3.2. of this Appendix.

1.4.2.3. Systems with CO2 measurement and carbon balance method

G

EDFW

,

i

(cid:3)

6,206

CO

,2
iD

(cid:2)

,

i

G
(cid:1)

FUEL
CO

,2
iA

where:

CO2D = CO2 concentration of the diluted exhaust

CO2A = CO2 concentration of the dilution air

(concentrations in volume % on wet basis)

This  equation  is  based  upon  the  carbon  balance  assumption  (carbon  atoms  supplied  to  the
engine are emitted as CO2) and derived through the following steps:

GEDFW,i = GEXHW,i × qi

91

and:

(cid:3)

q

i

G

EXHW

,

(cid:2)

6,206
(cid:1)
(cid:2)
CO

i

G

FUEL
(cid:1)

,

i

CO

,2
iA

(cid:2)

,2
iD

1.4.2.4. Systems with flow measurement

GEDFW,i = GEXHW,i × qi

(cid:2)

q

i

(cid:1)
G

G

TOTW
,
i
(cid:1)
G

TOTW

,

i

DILW

(cid:2)

,

i

1.4.3.

Full flow dilution system

The  final  reported  test  results  of  the  particulate  emission  shall  be  derived  through  the
following steps.

All calculations shall be based upon the average values of the individual modes (i) during the
sampling period.

GEDFW,i = GTOTW,i

1.4.4. Calculation of the particulate mass flow rate

The particulate mass flow rate shall be calculated as follows:

For the single filter method:

PT

mass

(cid:2)

M

f

M

SAM

(cid:1)
G

(cid:1)

(cid:2)

EDFW
1000

aver

where:

(GEDFW)aver over the test cycle shall be determined by summation of the average values of the
individual modes during the sampling period:

(cid:1)
G

EDFW

(cid:2)

aver

(cid:1)

n

(cid:1)

(cid:1)

1

i

G

EDFW

(cid:2)

,

i

WF
i

M

SAM

(cid:1)

n

(cid:1)

(cid:1)

1

i

M

SAM

,

i

where i = 1, . . . n

For the multiple filter method:

where i = 1, . . . n

PT

mass

(cid:2)

M

f

,

i

M

SAM

,

i

(cid:1)
G

(cid:1)

(cid:2)

aver

EDFW

,

i

1000

92

The particulate mass flow rate may be background corrected as follows:

For single filter method:

PT

mass

(cid:15)

(cid:7)
(cid:5)
(cid:5)
(cid:6)

M

f

M

SAM

(cid:14)

(cid:13)
(cid:11)
(cid:11)
(cid:12)

M

d

M

DIL

(cid:1)

(cid:13)
(cid:11)
(cid:11)
(cid:12)

n

(cid:1)

i

(cid:1)

i

(cid:1)

1

(cid:13)
(cid:11)
(cid:11)
(cid:12)

(cid:14)

1

1

DF

i

(cid:10)
(cid:8)
(cid:8)
(cid:9)

(cid:1)

WF

i

(cid:10)
(cid:8)
(cid:8)
(cid:9)

(cid:10)
(cid:8)
(cid:8)
(cid:9)

(cid:4)
(cid:2)
(cid:2)
(cid:3)

(cid:1)

(cid:1)
G

EDFW

(cid:2)

aver

1000

If more than one measurement is made, (Md/MDIL) shall be replaced with (Md/MDIL)aver

DF

(cid:3)

/4,13

(cid:1)
concCO

2

(cid:2)

(cid:1)
concCO

(cid:2)

concHC

(cid:2)

(cid:1)

10

(cid:1)

(cid:2)4

or:

DF=13,4/concCO2

For multiple filter method:

PT

mass

,

i

(cid:15)

(cid:6)
(cid:4)
(cid:4)
(cid:5)

M

f

,

i

M

SAM

,

i

(cid:14)

(cid:13)
(cid:11)
(cid:11)
(cid:12)

M

d

M

DIL

(cid:7)

(cid:13)
(cid:11)
(cid:11)
(cid:12)

(cid:14)

1

1

DF

i

(cid:10)
(cid:8)
(cid:8)
(cid:9)

(cid:10)
(cid:8)
(cid:8)
(cid:9)

(cid:3)
(cid:1)
(cid:1)
(cid:2)

(cid:7)

(cid:6)
(cid:4)
(cid:4)
(cid:5)

G

EDFW

,

i

1000

(cid:3)
(cid:1)
(cid:1)
(cid:2)

If more than one measurement is made, (Md/MDIL) shall be replaced with (Md/MDIL)aver

DF

(cid:3)

/4,13

(cid:1)
concCO

2

(cid:2)

(cid:1)
concCO

(cid:2)

concHC

(cid:2)

(cid:1)

10

(cid:1)

(cid:2)4

or:

DF=13,4/concCO2

1.4.5. Calculation of the specific emissions

The specific emission of particulates PT (g/kWh) shall be calculated in the following way1:

For the single filter method:

PT

(cid:2)

PT

mass

n

(cid:1)

(cid:1)

1

i

P
i

(cid:1)

WF
i

For the multiple filter method:

PT

(cid:2)

n

(cid:1)

(cid:1)

1

i

PT

mass

(cid:1)

WF
i

,

i

n

(cid:1)

(cid:1)

1

i

P
i

(cid:1)

WF
i

1

The particulate mass flow rate PTmass has to be multiplied by Kp (humidity correction factor for particulates quoted
in section 1.4.1).

93

                                                
1.4.6.

Effective weighting factor

For  the  single  filter  method,  the  effective  weighting  factor  WFE,i  for  each  mode  shall  be
calculated in the following way:

WF

,
iE

(cid:2)

where i = l, . . . n.

M

(cid:1)

,

i

(cid:1)
G
(cid:1)
G

(cid:1)

SAM
M

SAM

(cid:2)

(cid:2)

EDFW

aver

EDFW

,

i

The  value  of  the  effective  weighting  factors  shall  be  within  ±  0,005  (absolute  value)  of  the
weighting factors listed in Annex III, section 3.7.1.

-

2.

A new section 2 is inserted as follows

DATA EVALUATION AND CALCULATIONS (NRTC TEST)

The  two  following  measurement  principles  that  can  be  used  for  the  evaluation  of  pollutant
emissions over the NRTC cycle are described in this section:

the  gaseous  components  are  measured  in  the  raw  exhaust  gas  on  a  real  time  basis,  and  the
particulates are determined using a partial flow dilution system;

the gaseous components and the particulates are determined using a full flow dilution system
(CVS system).

2.1.

Calculation of  gaseous  emissions in the raw exhaust gas  and  of  the  particulate
emissions with a partial flow dilution system

2.1.1.

Introduction

The  instantaneous  concentration  signals  of  the  gaseous  components  are  used  for  the
calculation of the mass emissions by multiplication with the instantaneous exhaust mass flow
rate. The exhaust mass flow rate may be measured directly, or calculated using the methods
described  in  Annex  III,  Appendix  1,  section  2.2.3  (intake  air  and  fuel  flow  measurement,
tracer method, intake air and air/fuel ratio measurement). Special attention shall be paid to the
response times of the different instruments. These differences shall be accounted for by time
aligning the signals.

For particulates, the exhaust mass flow rate signals are used  for  controlling  the  partial  flow
dilution  system  to  take  a  sample  proportional  to  the  exhaust  mass  flow  rate.  The  quality  of
proportionality is checked by applying a regression analysis between sample and exhaust flow
as described in Annex III, Appendix 1, section 2.4.

2.1.2. Determination of the gaseous components

2.1.2.1. Calculation of mass emission

The mass of the pollutants Mgas (g/test) shall be determined by calculating the instantaneous
mass emissions from the raw concentrations of the pollutants, the u values from Table 4 (see
also previous paragraph 1.3.4.) and the exhaust mass flow, aligned for the transformation time
and integrating the instantaneous values over the cycle. Preferably, the concentrations should

94

be measured on a wet basis. If measured on a dry basis, the dry/wet correction as described
here  below  shall  be  applied  to  the  instantaneous  concentration  values  before  any  further
calculation is done.

Table 4. Values of the coefficients u – wet for various exhaust components

Gas

NOx

CO

HC

CO2

u

0,001587

0,000966

0,000479

conc

ppm

ppm

ppm

15,19

percent

The density of HC is based upon an average carbon to hydrogen ratio of 1:1,85.

The following formula shall be applied:

(cid:1)
ni

(cid:1)

(cid:1)

1

i

(cid:1)

u

conc

i

(cid:1)

G

EXHW

,

i

(cid:1)

1
f

 (in g/test)

Mgas =

where

u

=

ratio between density of exhaust component and density of exhaust gas

conci

=

instantaneous concentration of the respective component in the raw exhaust
gas, ppm

GEXHW,i=

instantaneous exhaust mass flow, kg/s

f

n

=

=

data sampling rate, Hz

number of measurements

For the calculation of NOx, the humidity correction factor kH, as described here below, shall
be used.

The  instantaneously  measured  concentration  shall  be  converted  to  a  wet  basis  as  described
here below, if not already measured on a wet basis

2.1.2.2. Dry/wet correction

If the instantaneously measured concentration is measured on a dry basis, it shall be converted
to a wet basis according to the following formulae.

concwet = kW x concdry

95

1

(cid:1)
conc

(cid:7)

conc

CO

CO

2

(cid:3)
(cid:1)
(cid:1)
(cid:2)

(cid:2)

(cid:7)

K

W

2

where

K

rW
,

1,

(cid:9)

(cid:6)
(cid:4)
(cid:4)
(cid:5)

(cid:7)

88,11

(cid:8)

005,0

(cid:8)

with

kW2 = 

where

(cid:2)

H

1,608
(cid:1)
1,608

(cid:1)

a

(cid:2)

*

H

a

1000

concCO2

=

dry CO2 concentration, %

concCO =

dry CO concentration, %

Ha

=

intake air humidity, g water per kg dry air

(cid:3)

H

a

p

,6
220
(cid:2)

p

a

B

(cid:1)

(cid:1)

R

a
R

a

(cid:1)

(cid:1)

p

a
10

(cid:1)

2

Ra: relative humidity of the intake air,%

pa: saturation vapour pressure of the intake air, kPa

pB: total barometric pressure, kPa

Note:  Ha  may  be  derived  from  relative  humidity  measurement,  as  described  above,  or  from
dewpoint measurement, vapour pressure measurement or dry/wet bulb measurement using the
generally accepted formulae.

2.1.2.3. NOx correction for humidity and temperature

As  the  NOx  emission  depends  on  ambient  air  conditions,  the  NOx  concentration  shall  be
corrected  for  humidity  and  ambient  air  temperature  with  the  factors  given  in  the  following
formula.

k

H =

-1

0,0182

(cid:1)

(cid:2)

H

a

(cid:1)

1
(cid:2)
10,71

(cid:3)

0,0045

(cid:1)
T

(cid:2)

a

(cid:2)

(cid:1)

298

with:

Ta

Ha

=

=

temperature of the intake air, K

humidity of the intake air,g water per kg dry air

(cid:3)

H

a

p

220
,6
(cid:2)

p

a

B

(cid:1)

(cid:1)

R

a
R

a

(cid:1)

(cid:1)

p

a
10

(cid:1)

2

96

Ra: relative humidity of the intake air,%

pa: saturation vapour pressure of the intake air, kPa

pB: total barometric pressure, kPa

Note:  Ha  may  be  derived  from  relative  humidity  measurement,  as  described  above,  or  from
dewpoint measurement, vapour pressure measurement or dry/wet bulb measurement using the
generally accepted formulae.

2.1.2.4. Calculation of the specific emissions

The  specific  emissions  (g/kWh)  shall  be  calculated  for  each  individual  component  in  the
following way:

Individual gas =

Mgas/Wact

Where

Wact

=

actual cycle work as determined in Annex III Section 4.6.2, kWh

2.1.3.

Particulate determination

2.1.3.1. Calculation of mass emission

The mass of particulates MPT (g/test) shall be calculated by either of the following methods.

a)

(cid:2)

M

PT

M

f M
(cid:1)

EDFW

M

SAM

1000

where

Mf

=

particulate mass sampled over the cycle, mg

MSAM =

mass of diluted exhaust gas passing the particulate collection filters, kg

MEDFW =

mass of equivalent diluted exhaust gas over the cycle, kg

The total mass of equivalent diluted exhaust gas mass over the cycle shall be determined as
follows:

M

EDFW

(cid:1)
ni

(cid:2) (cid:1)

(cid:1)

1

i

G

EDFW

i,

(cid:1)

1
f

G

EDFW

,

i

(cid:2)

G

EXHW

,

i

(cid:1)

q

i

(cid:2)

q

i

G

,

i

TOTW
(cid:1)

G

(cid:6)
(cid:4)
(cid:5)

G

TOTW

,

i

(cid:3)
(cid:1)
(cid:2)

DILW

,

i

97

where

GEDFW,i=

instantaneous equivalent diluted exhaust mass flow rate, kg/s

GEXHW,i=

instantaneous exhaust mass flow rate, kg/s

qi

=

instantaneous dilution ratio

GTOTW,I=

instantaneous diluted exhaust mass flow rate through dilution tunnel, kg/s

GDILW,i =

instantaneous dilution air mass flow rate, kg/s

data sampling rate, Hz

number of measurements

=

=

f

n

b)

M (cid:1)

PT

M
r
*s

f
1000

where

Mf

rs

=

=

with

where

(cid:2)

r
s

M

SE

M

EXHW

(cid:1)

particulate mass sampled over the cycle, mg

average sample ratio over the test cycle

M
M

SAM

TOTW

MSE

=

sampled exhaust mass over the cycle, kg

MEXHW =

total exhaust mass flow over the cycle, kg

MSAM =

MTOTW =

mass of diluted exhaust gas passing the particulate collection filters, kg

mass of diluted exhaust gas passing the dilution tunnel, kg

NOTE: In case of the total sampling type system, MSAM and MTOTW are identical.

98

2.1.3.2. Particulate correction factor for humidity

As  the  particulate  emission  of  diesel  engines  depends  on  ambient  air  conditions,  the
particulate concentration shall be corrected for ambient air humidity with the factor Kp given
in the following formula.

(cid:1)

k

p

(cid:1)
1

(cid:3)

0,0133

(cid:2)

1
(cid:1)

H

a

(cid:2)
(cid:2)
10,71

(cid:1)

where

Ha

=

humidity of the intake air in g water per kg dry air

(cid:3)

H

a

p

220
,6
(cid:2)

p

a

B

(cid:1)

(cid:1)

R

a
R

a

(cid:1)

(cid:1)

p

a
10

(cid:1)

2

Ra: relative humidity of the intake air, %

pa: saturation vapour pressure of the intake air, kPa

pB: total barometric pressure, kPa

Note:  Ha  may  be  derived  from  relative  humidity  measurement,  as  described  above,  or  from
dewpoint measurement, vapour pressure measurement or dry/wet bulb measurement using the
generally accepted formulae.

2.1.3.3. Calculation of the specific emissions

The particulate emission (g/kWh) shall be calculated in the following way:

PT

(cid:2)

M

(cid:1)

PT

/
WK
p

act

Where

Wact

=

actual cycle work as determined in Annex III Section 4.6.2, kWh

2.2.

Determination  of  gaseous  and  particulate  components  with  a  full  flow
dilution system

For calculation of the emissions in the diluted exhaust gas, it is necessary to know the diluted
exhaust gas mass flow rate. The total diluted exhaust gas flow over the cycle MTOTW (kg/test)
shall  be  calculated  from  the  measurement  values  over  the  cycle  and  the  corresponding
calibration data of the flow measurement device (V0 for PD, KV for CFI, Cd for SST) by either
of the methods described in the following section 2.2.1 may be used. If the total sample mass
of particulates (MSAM) and gaseous pollutants exceeds 0,5 % of the total CVS flow (MTOTW),
the CVS flow shall be corrected for MSAM or the particulate sample flow shall be returned to
the CVS prior to the flow measuring device.

99

2.2.1. Determination of the Diluted Exhaust Gas Flow

PD-CVS system

The calculation of the mass flow over the cycle is as follows, if the temperature of the diluted
exhaust is kept within ± 6 K over the cycle by using a heat exchanger

MTOTW =

1,293 * V0 * NP * (pB - p1) * 273 / (101,3 * T)

where

MTOTW =

mass of the diluted gas on wet basis over the cycle

V0

NP

pB

p1

T

=

=

=

=

volume of gas pumped per revolution under test conditions, m³/rev

total revolutions of pump per test

atmospheric pressure in the test cell, kPa

pressure depression below atmospheric at pump inlet, kPa

=

average temperature of the diluted exhaust gas at pump inlet over thecycle, K

If a system with flow compensation is used  (i.e.  without  heat  exchanger),  the  instantaneous
mass  emissions  shall  be  calculated  and  integrated  over  the  cycle.  In  this  case,  the
instantaneous mass of the diluted exhaust gas shall be calculated as follows:

MTOTW,i=

1,293 * V0 * NP,i * (pB - p1) * 273 / (101,3 . T)

where

NP,i

=

total revolutions of pump per time interval

CFI-CVS system

The calculation of the mass flow over the cycle is as follows, if the temperature of the diluted
exhaust is kept within ± 11K over the cycle by using a heat exchanger:

MTOTW =

1,293 * t * Kv * pA / T 0,5

where

MTOTW =

mass of the diluted gas on wet basis over the cycle

t

KV

pA

T

=

cycle time, s

=

calibration coefficient of the critical flow venturi for standard conditions,

=

=

absolute pressure at venturi inlet, kPa

absolute temperature at venturi inlet, K

100

If a system with flow compensation is used  (i.e.  without  heat  exchanger),  the  instantaneous
mass  emissions  shall  be  calculated  and  integrated  over  the  cycle.  In  this  case,  the
instantaneous mass of the diluted exhaust gas shall be calculated as follows:

MTOTW,i=

1,293 * (cid:1)ti * KV * pA / T 0,5

where

(cid:1)ti

=

time interval, s

SST-CVS system

The calculation of the mass flow over the cycle is as follows if the temperature of the diluted
exhaust is kept within ± 11 K over the cycle by using a heat exchanger:

M

TOTW

,1(cid:3)

293

*

Q

SSV

where,

Q

SSV

(cid:15)

2
PCdA

0

d

(cid:1)
r

(cid:6)
(cid:4)
(cid:4)
(cid:5)

1

T

A

.1

4286

(cid:13)

r

.1

7143

(cid:2)

(cid:14)

(cid:12)
(cid:10)
(cid:10)
(cid:11)

1

(cid:13)

(cid:1)

1

4

r

.1

4286

(cid:9)
(cid:7)
(cid:7)
(cid:8)

(cid:3)
(cid:1)
(cid:1)
(cid:2)

A0

= collection of constants and units conversions

= 0,006111 in SI units of 

(cid:6)
(cid:4)(cid:4)
(cid:5)

3

m
min

(cid:6)
(cid:4)
(cid:3)
(cid:1)(cid:1)
(cid:4)
(cid:4)
(cid:2)
(cid:5)

1

2

K
kPa

(cid:3)
(cid:1)
(cid:6)
(cid:4)
(cid:1)
(cid:5)
(cid:1)
(cid:2)

1
mm

2

(cid:3)
(cid:1)
(cid:2)

d = diameter of the SST throat, m

Cd = discharge coefficient of the SSV

PA = absolute pressure at venturi inlet, kPa

T = temperature at the venturi inlet, K

r = ratio of the SST throat to inlet absolute, static pressure = 

(cid:2)1

P(cid:1)
AP

ß = ratio of the SST throat diameter, d, to the inlet pipe inner diameter = 

d
D

If a system with flow compensation is used  (i.e.  without  heat  exchanger),  the  instantaneous
mass  emissions  shall  be  calculated  and  integrated  over  the  cycle.  In  this  case,  the
instantaneous mass of the diluted exhaust gas shall be calculated as follows:

M

TOTW

(cid:2)

,1

293

*

Q

*

(cid:1)

t

i

SSV

101

where

Q

SSV

(cid:14)

2
PCdA

0

d

*

A

(cid:1)
r

(cid:6)
(cid:4)
(cid:4)
(cid:5)

1

T

.1

4286

(cid:13)

r

.1

7143

(cid:12)
(cid:2)
(cid:10)
(cid:10)
(cid:11)

1

(cid:13)

(cid:1)

1

4

r

.1

4286

(cid:9)
(cid:7)
(cid:7)
(cid:8)

(cid:3)
(cid:1)
(cid:1)
(cid:2)

(cid:1)ti

=

time interval, s

The  real  time  calculation  shall  be  initialized  with  either  a  reasonable  value  for  Cd,  such  as
0.98, or a reasonable value of Qssv. If the calculation is initialized with Qssv, the initial value of
Qssv shall be used to evaluate Re.

During  all  emissions  tests,  the  Reynolds  number  at  the  SST  throat  must  be  in  the  range  of
Reynolds numbers used to derive the calibration curve developed in Appendix 2 section 3.2.

2.2.2. NOx Correction for Humidity

As  the  NOx  emission  depends  on  ambient  air  conditions,  the  NOx  concentration  shall  be
corrected for ambient air humidity with the factors given in the following formulae.

k

H =

-1

0,0182

(cid:1)

(cid:2)

H

a

(cid:1)

1
(cid:2)
10,71

(cid:3)

0,0045

(cid:1)
T

(cid:2)

a

(cid:2)

(cid:1)

298

where,

Ta = temperature of the air in K

Ha = humidity of the intake air water per kg dry air

in which,

Ra

pa

pB

=

=

=

(cid:2)

H

a

p

220
,6
(cid:4)

p

a

B

(cid:3)

(cid:3)

R

a
R

a

(cid:3)

(cid:3)

p

a
10

(cid:1)

2

relative humidity of the intake air, %

saturation vapour pressure of the intake air, kPa

total barometric pressure, kPa

Note:  Ha  may  be  derived  from  relative  humidity  measurement,  as  described  above,  or  from
dewpoint measurement, vapour pressure measurement or dry/wet bulb measurement using the
generally accepted formulae.

2.2.3. Calculation of the Emission Mass Flow

2.2.3.1. Systems with Constant Mass Flow

For systems with heat exchanger, the mass of the pollutants MGAS (g/test) shall be determined
from the following equation:

MGAS = u x conc x MTOTW

102

where

u

= ratio between density of the exhaust component and density of diluted exhaust gas,
as reported in Table 4, point 2.1.2.1

conc

=  average  background  corrected  concentrations  over  the  cycle  from  integration
(mandatory for NOx and HC) or bag measurement, ppm

MTOTW = total mass of diluted exhaust gas over the cycle as determined in section 2.2.1, kg

As  the  NOx  emission  depends  on  ambient  air  conditions,  the  NOx  concentration  shall  be
corrected for ambient air humidity with the factor kH, as described in section 2.2.2.

Concentrations measured on a dry basis shall be converted to a wet basis in accordance with
section 1.3.2 of this Appendix.

2.2.3.1.1.

Determination of the Background Corrected Concentrations

The  average  background  concentration  of  the  gaseous  pollutants  in  the  dilution  air  shall  be
subtracted from measured concentrations to get the net concentrations of the pollutants. The
average  values  of  the  background  concentrations  can  be  determined  by  the  sample  bag
method or by continuous measurement with integration. The following formula shall be used.

conc =

conce - concd * (1 - (1/DF))

where,

conc

conce

concd

DF

=

=

=

=

concentration of the respective pollutant in the diluted exhaust gas, corrected
by the amount of the respective pollutant contained in the dilution air, ppm

concentration of the respective pollutant measured in the diluted exhaust gas,
ppm

concentration of the respective pollutant measured in the dilution air, ppm

dilution factor

The dilution factor shall be calculated as follows:

DF =

4,13

conc

COe

2

(cid:2)

(

conc

HCe

(cid:2)

conc

eCO

(cid:1)

)

10

(cid:1)

4

2.2.3.2. Systems with Flow Compensation

For  systems  without  heat  exchanger,  the  mass  of  the  pollutants  MGAS  (g/test)  shall  be
determined by calculating the instantaneous mass emissions and integrating the instantaneous
values  over  the  cycle.  Also,  the  background  correction  shall  be  applied  directly  to  the
instantaneous concentration value. The following formulae shall be applied:

M

GAS

n

(cid:3) (cid:1)

(cid:1)
M

i

(cid:1)

1

TOTW

,

i

(cid:1)

conc

ie
,

(cid:2)
(cid:1)
(cid:2)
Mu

(cid:1)

(cid:1)

conc

d

TOTW

(cid:1)
(cid:2)(cid:1)
/11

(cid:2)

(cid:1)

(cid:2)u

DF

103

 
where,

conce,i =

concd

u

=

=

instantaneous concentration of the respective pollutant measured in the diluted
exhaust gas, ppm

concentration of the respective pollutant measured in the dilution air, ppm

ratio between density of the exhaust component and density of diluted exhaust
gas, as reported in Table 4, point 2.1.2.1

MTOTW,i =

instantaneous mass of the diluted exhaust gas (see section 2.2.1), kg

MTOTW =

total mass of diluted exhaust gas over the cycle (see section 2.2.1), kg

DF

=

dilution factor as determined in point 2.2.3.1.1.

As  the  NOx  emission  depends  on  ambient  air  conditions,  the  NOx  concentration  shall  be
corrected for ambient air humidity with the factor kH, as described in section 2.2.2.

2.2.4. Calculation of the Specific Emissions

The  specific  emissions  (g/kWh)  shall  be  calculated  for  each  individual  component  in  the
following way:

Individual gas =

Mgas/Wact

Where

Wact

=

actual cycle work as determined in Annex III Section 4.6.2, kWh

2.2.5. Calculation of the particulate emission

2.2.5.1. Calculation of the Mass Flow

The particulate mass MPT (g/test) shall be calculated as follows:

MPT = 

M

f

M

SAM

(cid:1)

M
TOTW
1000

Mf

=

particulate mass sampled over the cycle, mg

MTOTW =

total mass of diluted exhaust gas over the cycle as determined in section 2.2.1,
kg

MSAM

=

mass of diluted exhaust gas taken from the dilution tunnel for collecting
particulates, kg

and,

Mf

Mf,p

=

=

Mf,p + Mf,b, if weighed separately, mg

particulate mass collected on the primary filter, mg

104

Mf,b

=

particulate mass collected on the back-up filter, mg

If a double dilution system is used, the mass of the secondary dilution air shall be subtracted
from the total mass of the double diluted exhaust gas sampled through the particulate filters.

MSAM =

MTOT - MSEC

where,

MTOT =

mass of double diluted exhaust gas through particulate filter, kg

MSEC =

mass of secondary dilution air, kg

If the particulate background level of the dilution air is determined in accordance with Annex
III,  section  4.4.4,  the  particulate  mass  may  be  background  corrected.  In  this  case,  the
particulate mass (g/test) shall be calculated as follows:

(cid:7)
(cid:5)
(cid:5)
(cid:6)

M

f

M

SAM

(cid:14)

(cid:13)
(cid:11)
(cid:11)
(cid:12)

M

d

M

DIL

(cid:13)
(cid:14)(cid:1)
(cid:11)(cid:11)
1
(cid:12)

1

DF

(cid:10)
(cid:8)(cid:8)
(cid:9)

(cid:10)
(cid:8)
(cid:8)
(cid:9)

(cid:4)
(cid:2)
(cid:2)
(cid:3)

M

(cid:1)

TOTW

1000

MPT = 

where,

Mf, MSAM, MTOTW = see above

MDIL

Md

DF

=

=

mass of primary dilution air sampled by background particulate sampler, kg

mass of the collected background particulates of the primary dilution air, mg

=

dilution factor as determined in point 2.2.3.1.1

2.2.5.2. Particulate correction factor for humidity

As  the  particulate  emission  of  diesel  engines  depends  on  ambient  air  conditions,  the
particulate concentration shall be corrected for ambient air humidity with the factor Kp given
in the following formula.

(cid:1)

k

p

(cid:1)
1

(cid:3)

0,0133

(cid:2)

1
(cid:1)

H

a

(cid:2)
(cid:2)
10,71

(cid:1)

where

Ha

=

humidity of the intake air in g water per kg dry air

(cid:3)

H

a

p

220
,6
(cid:2)

p

a

B

(cid:1)

(cid:1)

R

a
R

a

(cid:1)

(cid:1)

p

a
10

(cid:1)

2

Ra: relative humidity of the intake air, %

pa: saturation vapour pressure of the intake air, kPa

pB: total barometric pressure, kPa

105

Note:  Ha  may  be  derived  from  relative  humidity  measurement,  as  described  above,  or  from
dewpoint measurement, vapour pressure measurement or dry/wet bulb measurement using the
generally accepted formulae.

2.2.5.3. Calculation of the Specific Emission

The particulate emission (g/kWh) shall be calculated in the following way:

PT

(cid:2)

M

(cid:1)

PT

/
WK
p

act

Where

Wact =

actual  cycle  work  as  determined 

in  Annex  III  Section  4.6.2,  kWh

106

-

The following appendix 4 to Annex III is inserted:

APPENDIX 4

NRTC ENGINE DYNAMOMETER SCHEDULE

Time Norm. Norm.
Speed Torque

Time Norm. Norm.
Speed Torque

Time Norm. Norm.
Speed Torque

s
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51

%

%

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
2
4
7
9
17
33
57
44
31
22
33
80
105
98
104
104
96
101
102
102

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3
3
3
3
3
3
6
6
1
13
18
21
20
42
46
33
0
27
43
49
47
70
36
65
71
62
51
50

s
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102

%
102
102
102
89
82
47
23
1
1
1
1
1
1
1
0
1
9
25
64
60
63
62
64
58
65
65
68
69
71
74
71
73
73
73
70
70
65
66
64
65
66
67
69
69
66
71
75
72
74
75
73

%

46
41
31
2
0
1
1
3
8
3
5
6
4
4
6
4
21
56
26
31
20
24
8
44
10
12
23
30
30
15
23
20
21
19
33
34
47
47
53
45
38
49
39
39
42
29
29
23
22
24
30

107

s
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153

%

%

74
77
76
74
72
75
78
102
103
103
103
103
104
103
103
103
102
103
102
103
102
103
103
103
104
104
104
103
104
104
101
102
102
102
103
104
102
104
103
104
102
103
79
51
24
13
19
45
34
14
8

24
6
12
39
30
22
64
34
28
28
19
32
25
38
39
34
44
38
43
34
41
44
37
27
13
30
19
28
40
32
63
54
52
51
40
34
36
44
44
33
27
26
53
37
23
33
55
30
7
4
16

Time Norm. Norm.
Speed Torque

Time Norm. Norm.
Speed Torque

Time Norm. Norm.
Speed Torque

s
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204

%

%

15
39
39
35
27
43
14
10
15
35
60
55
47
16
0
0
0
0
2
10
28
33
36
19
1
0
1
1
1
1
1
1
1
1
1
8
20
49
41
31
28
21
31
21
0
0
3
3
12
14
16

6
47
4
26
38
40
23
10
33
72
39
31
30
7
6
8
8
2
17
28
31
30
0
10
18
16
3
4
5
6
5
3
4
4
6
18
51
19
13
16
21
17
21
8
14
12
8
22
20
20
17

s
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255

%

%

18
34
33
31
31
33
18
29
51
11
9
33
25
17
29
66
40
13
24
50
23
20
11
23
31
24
33
3
7
10
19
10
7
5
6
6
5
5
28
25
53
8
40
29
39
42
18
51
90
84
85

20
27
32
41
43
37
26
18
14
13
12
15
20
25
31
36
66
50
16
26
64
81
83
79
76
68
59
59
25
21
20
4
5
4
4
4
4
7
16
28
52
50
26
48
54
60
48
54
88
103
103

108

s
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306

%
102
58
64
56
51
52
63
71
33
47
43
42
42
75
68
86
66
37
45
68
80
92
90
82
94
90
96
70
55
70
79
81
71
92
82
61
52
24
20
39
39
63
53
51
48
39
35
36
29
28
31

%

84
66
97
80
67
96
62
6
16
45
56
27
64
74
96
61
0
0
37
96
97
96
97
96
81
85
65
96
95
96
96
71
60
65
63
47
37
0
7
48
54
58
31
24
40
0
18
16
17
21
15

Time Norm. Norm.
Speed Torque

Time Norm. Norm.
Speed Torque

Time Norm. Norm.
Speed Torque

s
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357

%

%

31
43
49
78
78
66
78
84
57
36
20
19
9
5
7
15
12
13
15
16
16
15
17
20
21
20
23
30
63
83
61
26
29
68
80
88
99
102
100
74
57
76
84
86
81
83
65
93
63
72
56

10
19
63
61
46
65
97
63
26
22
34
8
10
5
11
15
9
27
28
28
31
20
0
34
25
0
25
58
96
60
0
0
44
97
97
97
88
86
82
79
79
97
97
97
98
83
96
72
60
49
27

s
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408

%

%

0
13
11
24
53
83
44
46
50
52
98
69
49
0
8
7
13
6
5
12
46
30
28
9
21
4
43
85
66
39
34
55
42
39
0
5
14
54
90
66
48
93
67
65
98
97
97
98
61
0
32

29
18
25
28
34
65
80
77
76
45
61
61
63
32
10
17
16
11
9
9
12
15
26
13
16
24
36
65
78
63
32
46
47
42
27
14
14
24
60
53
70
77
79
46
69
80
74
75
56
42
36

109

s
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459

%

%

34
68
102
62
41
71
91
89
89
88
78
98
64
90
88
97
100
81
74
76
76
85
84
83
83
86
89
86
87
88
88
87
85
88
88
84
83
77
74
76
46
78
79
82
81
79
78
78
78
75
73

43
83
48
0
39
86
52
55
56
58
69
39
61
34
38
62
53
58
51
57
72
72
60
72
72
72
72
72
72
72
71
72
71
72
72
72
73
73
73
72
77
62
35
38
41
37
35
38
46
49
50

Time Norm. Norm.
Speed Torque

Time Norm. Norm.
Speed Torque

Time Norm. Norm.
Speed Torque

s
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510

%

%

79
79
83
53
40
51
75
89
93
89
86
81
78
78
76
79
82
86
88
92
97
73
36
63
78
69
67
72
71
78
81
75
60
50
66
51
68
29
24
64
90
100
94
84
79
75
78
80
81
81
83

58
71
44
48
48
75
72
67
60
73
73
73
73
73
73
73
73
73
72
71
54
43
64
31
1
27
28
9
9
36
56
53
45
37
41
61
47
42
73
71
71
61
73
73
73
72
73
73
73
73
73

s
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561

%

%

73
73
73
73
73
73
72
73
73
73
73
73
72
56
48
71
44
23
10
14
37
45
18
51
33
17
45
30
14
18
14
11
2
26
72
70
62
68
53
50
50
43
45
35
61
50
55
49
70
39
3

85
84
85
86
85
85
85
85
83
79
78
81
82
94
66
35
51
60
64
63
70
76
78
76
75
81
76
76
80
71
71
71
65
31
24
64
77
80
83
83
83
85
86
89
82
87
85
89
87
91
72

110

s
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612

%

%

43
30
40
37
37
43
70
77
79
85
83
86
85
70
50
38
30
75
84
85
86
86
89
99
77
81
89
49
79
104
103
102
102
103
102
103
93
86
76
59
46
40
72
72
67
68
67
68
77
58
22

25
60
45
32
32
70
54
47
66
53
57
52
51
39
5
36
71
53
40
42
49
57
68
61
29
72
69
56
70
59
54
56
56
61
64
60
72
73
73
49
22
65
31
27
44
37
42
50
43
4
37

Time Norm. Norm.
Speed Torque

Time Norm. Norm.
Speed Torque

Time Norm. Norm.
Speed Torque

s
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663

%

%

57
68
73
40
42
64
64
67
65
68
65
81
37
24
68
70
76
71
73
76
77
77
77
77
76
76
77
77
78
77
77
79
78
80
82
84
83
83
81
80
78
76
76
76
79
78
81
83
84
86
87

69
38
2
14
38
69
74
73
73
73
49
0
25
69
71
71
70
72
69
70
72
72
72
70
71
71
71
71
70
70
71
72
70
70
71
71
71
73
70
71
71
70
70
71
71
71
70
72
71
71
71

s
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765

%
102
102
102
102
102
102
102
102
104
104
102
102
102
104
101
103
102
103
103
102
103
103
102
103
102
103
102
103
102
104
103
102
103
103
103
102
103
102
103
102
102
103
102
102
102
102
102
102
102
102
103

%

64
69
68
70
69
70
70
62
38
15
24
45
47
40
52
32
50
30
44
40
43
41
46
39
41
41
38
39
46
46
49
45
42
46
38
48
35
48
49
48
46
47
49
42
52
57
55
61
61
58
58

s
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714

%

%

72
72
71
71
71
70
72
71
71
71
72
69
70
72
70
71
71
71
71
71
71
71
68
68
67
69
68
71
68
69
72
69
69
71
71
69
71
68
69
70
68
70
72
68
69
68
71
64
69
69
69

92
91
90
90
91
90
90
91
90
90
92
93
90
93
91
89
91
90
90
92
91
93
93
98
98
100
99
100
99
100
102
101
100
102
102
102
102
102
100
102
102
102
102
102
102
100
102
101
102
102
101

111

Time Norm. Norm.
Speed Torque

Time Norm. Norm.
Speed Torque

Time Norm. Norm.
Speed Torque

s
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816

%
102
102
102
102
103
102
102
103
102
102
103
84
48
48
48
48
48
48
67
105
105
105
105
105
105
89
52
48
48
48
48
48
52
51
51
51
52
52
57
98
105
105
105
105
105
105
104
100
94
87
81

%

59
54
63
61
55
60
72
56
55
67
56
42
7
6
6
7
6
7
21
59
96
74
66
62
66
41
5
5
7
5
6
4
6
5
6
6
5
5
44
90
94
100
98
95
96
92
97
85
74
62
50

s
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867

%

%

46
39
32
28
26
23
23
20
19
18
17
20
24
21
26
24
23
22
21
24
24
22
22
21
31
27
26
26
25
21
20
21
15
12
9
8
7
6
6
6
6
6
5
8
7
20
52
38
33
29
22

81
80
80
81
80
80
80
80
81
80
81
80
81
81
80
80
80
80
81
81
81
81
81
81
81
81
80
80
81
80
81
83
83
83
83
83
83
83
83
83
83
83
76
49
51
51
78
80
81
83
83

112

s
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918

%

%

83
83
83
83
83
83
83
83
83
83
59
50
51
51
51
50
50
50
50
50
51
51
51
63
81
81
81
81
80
81
81
81
81
81
81
81
81
81
80
80
81
81
81
81
81
83
80
80
83
81
83

16
12
9
8
7
6
6
6
6
6
4
5
5
5
5
5
5
5
5
5
5
5
5
50
34
25
29
23
24
24
28
27
22
19
17
17
17
15
15
28
22
24
19
21
20
26
63
59
100
73
53

Time Norm. Norm.
Speed Torque

Time Norm. Norm.
Speed Torque

Time Norm. Norm.
Speed Torque

s
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969

%

%

80
81
80
81
82
83
83
83
83
83
83
83
83
83
83
83
71
49
69
81
81
81
81
81
81
81
81
80
81
81
81
81
81
81
81
81
81
81
81
81
81
81
81
80
81
83
81
81
80
81
81

76
61
50
37
49
37
25
17
13
10
8
7
7
6
6
6
5
24
64
50
43
42
31
30
35
28
27
27
31
41
41
37
43
34
31
26
23
27
38
40
39
27
33
28
34
72
49
51
55
48
36

s
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020

%

%

39
38
41
30
23
19
25
29
47
90
75
60
48
41
30
24
20
21
29
29
27
23
25
26
22
20
17
23
65
54
50
41
35
37
29
28
24
19
16
16
23
17
13
27
58
60
46
41
36
26
18

81
81
80
81
81
81
81
81
83
81
81
80
81
81
81
80
81
81
81
81
81
81
81
81
81
81
81
81
83
81
81
81
81
81
81
81
81
81
81
80
83
83
83
83
81
81
81
80
80
81
86

113

s
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071

%

%

82
79
82
83
83
83
76
79
86
82
84
86
85
83
83
83
84
83
76
78
75
86
83
81
81
79
80
84
79
87
82
84
82
81
85
86
79
78
74
78
80
80
82
83
79
83
86
64
24
49
77

35
53
30
29
32
28
60
51
26
34
25
23
22
26
25
37
14
39
70
81
71
47
35
43
41
46
44
20
31
29
49
21
56
30
21
16
52
60
55
84
54
35
24
43
49
50
12
14
14
21
48

Time Norm. Norm.
Speed Torque

Time Norm. Norm.
Speed Torque

Time Norm. Norm.
Speed Torque

s
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122

%
103
98
101
99
103
103
103
103
103
102
101
102
102
96
99
102
100
100
98
102
95
102
102
98
93
101
95
101
94
97
97
93
98
103
103
103
103
103
103
103
103
103
102
102
101
102
103
102
99
96
74

%

11
48
34
39
11
19
7
13
10
13
29
25
20
60
38
24
31
28
3
26
64
23
25
42
68
25
64
35
59
37
60
98
53
13
11
11
13
10
10
11
10
10
18
31
24
19
10
12
56
59
28

s
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224

%

%

76
76
67
75
75
73
68
74
76
76
74
74
73
74
74
70
71
73
73
72
64
70
66
68
30
70
66
76
74
69
68
68
68
68
68
68
54
41
27
14
0
0
0
0
0
0
0
0
0
0
0

8
7
45
13
12
21
46
8
11
14
11
18
22
20
19
22
23
19
19
20
60
39
56
64
68
38
47
14
18
46
62
62
62
62
62
62
50
37
25
12
0
0
0
0
0
0
0
0
0
0
0

s
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173

%

%

62
29
74
40
2
29
65
69
56
40
54
92
67
42
2
34
80
67
70
65
57
29
31
1
22
52
96
72
28
35
68
27
14
38
59
99
86
53
36
47
42
34
2
21
15
13
10
13
10
7
13

66
74
64
69
76
72
66
54
69
69
73
63
61
72
78
76
67
70
53
72
60
74
69
76
74
72
62
54
72
72
64
74
76
69
66
64
51
70
72
71
70
67
74
75
74
75
76
75
75
75
75

114

Time Norm. Norm.
Torque
Speed
%
%

s

Time Norm. Norm.
Speed Torque

s

%

%

Time Norm. Norm.
Speed Torque

s
1225
226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238

%

%

0
0
0
0
0
0
0
0
0
0
0
0
0
0

0
0
0
0
0
0
0
0
0
0
0
0
0
0

A graphical display of the NRTC dynamometer schedule is shown here below

Speed [%]

NRTC dynamometer schedule

120

100

80

60

40

20

0

0

Torque [%]

120

100

80

60

40

20

0

200

400

600

800

1000

1200

0

200

400

800

1000

1200

600

time [ s ]

115

-

The following new appendix 5 to Annex III is inserted:

“Appendix 5

Durability requirements

1.

EMISSION DURABILITY PERIOD AND DETERIORATION FACTORS.

This appendix shall apply to CI engines Stage IIIA and IIIB only.

* * * * *

1.1.

Manufacturers shall determine a Deterioration Factor (DF) value for each regulated
pollutant for all Stage IIIA and IIIB engine families. Such DFs shall be used for type
approval and production line testing.

1.1.1

Test to establish DF’s shall be conducted as follows:

1.1.1.1 The manufacturer shall conduct durability tests to accumulate engine operating hours
according  to  a  test  schedule  that  is  selected  on  the  basis  of  good  engineering
judgement to be representative of in-use engine operation in respect to characterizing
emission  performance  deterioration.  The  durability  test  period  should  typically
represent  the  equivalent  of  at  least  one  quarter  of  the  Emission  Durability  Period
(EDP).

Service  accumulation  operating  hours  may  be  acquired  through  running  engines  on  a
dynamometer  test  bed  or  from  actual  in-field  machine  operation.  Accelerated
durability  tests  can  be  applied  whereby  the  service  accumulation  test  schedule  is
performed  at  a  higher  load  factor  than  typically  experienced  in  the  field.  The
acceleration  factor  relating  the  number  of  engine  durability  test  hours  to  the
equivalent  number  of  EDP  hours  shall  be  determined  by  the  engine  manufacturer
based on good engineering judgement.

During  the  period  of  the  durability  test,  no  emission  sensitive  components  can  be
serviced or replaced other than to the routine service schedule recommended by the
manufacturer.

The  test  engine,  subsystems,  or  components  to  be  used  to  determine  exhaust
emission  DF’s  for  an  engine  family,  or  for  engine  families  of  equivalent  emission
control system technology, shall be selected by the engine manufacturer on the basis
of good engineering judgement. The criteria is that the test engine should represent
the  emission  deterioration  characteristic  of  the  engine  families  that  will  apply  the
resulting DF values for certification approval. Engines of different bore  and stroke,
different configuration, different air management systems, different fuel systems can
be  considered  as  equivalent  in  respect  to  emissions  deterioration  characteristics  if
there is a reasonable technical basis for such determination.

DF values from another manufacturer can be applied if there is a reasonable basis for
considering  technology  equivalence  with  respect  to  emissions  deterioration,  and
evidence that the tests have been carried according to the specified requirements.

116

Emissions  testing  will  be  performed  according  to  the  procedures  defined  in  this
directive for the test engine after initial run-in but before any service accumulation,
and  at  the  completion  of  the  durability.  Emission  tests  can  also  be  performed  at
intervals during the service accumulation test period, and applied in determining the
deterioration trend.

1.1.1.2 The  service  accumulation  tests  or  the  emissions  tests  performed  to  determine

deterioration must not be witnessed by the approval authority.

1.1.1.3 Determination of DF values from Durability Tests

An additive DF is defined as the value obtained by subtraction of the emission value
determine  at  the  beginning  of  the  EDP,  from  the  emissions  value  determined  to
represent the emission performance at the end of the EDP.

A  multiplicative  DF  is  defined  as  the  emission  level  determined  for  the  end  of  the
EDP divided by the emission value recorded at the beginning of the EDP.

Separate  DF  values  shall  be  established  for  each  of  the  pollutants  covered  by  the
legislation. In the case of establishing a DF value relative to the NOx+HC standard,
for  an  additive  DF,  this  is  determined  based  on  the  sum  of  the  pollutants
notwithstanding  that  a  negative  deterioration  for  one  pollutant  may  not  offset
deterioration for the other. For a multiplicative NOx+HC DF, separate HC and NOx
DF’s  shall  be  determined  and  applied  separately  when  calculating  the  deteriorated
emission  levels  from  an  emissions  test  result  before  combining  the  resultant
deteriorated NOx and HC values to esatablish compliance with the standard.

In cases where the testing is not conducted for the full EDP, the emission values at
the end of the EDP is determined by extrapolation of the emission deterioration trend
established for the test period, to the full EDP.

When  emissions  test  results  have  been  recorded  periodically  during  the  service
accumulation  durability  testing,  standard  statistical  processing  techniques  based  on
good practice shall be applied to determine the emission levels at the end of the EDP;
statistical  significance  testing  can  be  applied  in  the  determination  of  the  final
emissions values.

If the calculation results in a value of less than 1.00 for a multiplicative DF, or less
than 0.00 for an additive DF, then the DF shall be 1.0 or 0.00, respectively.

117

1.1.1.4 A manufacturer may, with the approval of the type approval authority, use DF values
established  from  results  of  durability  tests  conducted  to  obtain  DF  values  for
certification of on-road HD CI engines. This will be allowed if there is technological
equivalency  between  the  test  on-road  engine  and  the  non-road  engine  families
applying the DF values for certification. The DF values derived from on-road engine
emission  durability  test  results,  must  be  calculated  on  the  basis  of  EDP  values
defined in Paragraph 2.

1.1.1.5 In the case where an engine family uses established technology, an analysis based on
good engineering practices may be used in lieu of testing to determine a deterioration
factor for that engine family subject to approval of the type approval authority.

1.2

DF information in approval applications

1.2.1

Additive DF’s shall be specified for each pollutant in an engine family certification
application for CI engines not using any aftertreatment device.

1.2.2 Multiplicative  DF’s  shall  be  specified  for  each  pollutant  in  an  engine  family

certification application for CI engines using an aftertreatment device.

1.2.3

The  manufacture  shall  furnish  the  Type  Approval  agency  on  request  with
information  to  support  the  DF  values.  This  would  typically  include  emission  test
results,  service  accumulation  test  schedule,  maintenance  procedures  together  with
information  to  support  engineering  judgements  of  technological  equivalency,  if
applicable.

2.

EMISSION DURABILITY PERIODS FOR STAGE IIIA AND IIIB ENGINES.

2.1.

Manufacturers shall use the EDP inTable 1 of this paragraph.

Table 1: EDP categories for CI Stage IIIA and IIIB Engines (hours)

Useful life (hours)

EDP

3.000

Category (power
band)

(cid:1) 37 kW

(constant  speed
engines)

(cid:1) 37 kW

5.000

constant

(not 
speed engines)

(cid:2) 37 kW

Engines  for  the
inland
in 
use 
waterway
vessels

8.000

10.000

118

4.

-

ANNEX V IS AMENDED AS FOLLOWS:

The current headings are replaced by the following:

TECHNICAL  CHARACTERISTICS  OF  REFERENCE  FUEL  PRESCRIBED  FOR
APPROVAL  TESTS  AND  TO  VERIFY  CONFORMITY  OF  PRODUCTION

NON-ROAD MOBILE MACHINERY REFERENCE FUEL FOR CI ENGINES TYPE
APPROVED  TO  MEET  STAGE  I,  II  and  IIIA  LIMIT  VALUES  AND  FOR
ENGINES TO BE USED IN INLAND WATERWAY VESSELS.

-

The following new headings and tables are inserted after current table on reference
fuel for diesel as follows:

NON-ROAD MOBILE MACHINERY REFERENCE FUEL FOR CI ENGINES TYPE
APPROVED TO MEET STAGE IIIB LIMIT VALUES.

Parameter

Unit

Test Method

Minimum maximum

Limits (1)

Cetane number (2)

Density at 15°C

Distillation:

 50% point

 95% point

- Final boiling point

Flash point

CFPP

Viscosity at 40°C

Polycyclic aromatic
hydrocarbons

Sulphur content (3)

Copper corrosion

Conradson carbon residue
(10% DR)

Ash content

54,0

EN-ISO 5165

kg/m3

833

837

EN-ISO 3675

-

350

370

-

-5

3,3

6,0

10

EN-ISO 3405

EN-ISO 3405

EN-ISO 3405

EN 22719

EN 116

EN-ISO 3104

IP 391

ASTM D 5453

class 1

EN-ISO 2160

0,2

EN-ISO 10370

0,01

EN-ISO 6245

°C

°C

°C

°C

°C

mm2/s

% m/m

mg/kg

% m/m

% m/m

245

345

-

55

-

2,3

3,0

-

-

-

-

119

Parameter

Unit

Test Method

Minimum maximum

Limits (1)

Water content

Neutralisation (strong acid)
number

Oxidation stability (4)

Lubricity (HFRR wear scar
diameter at 60°C)

% m/m

mg
KOH/g

mg/ml

µm

-

-

-

-

0,02

EN-ISO 12937

0,02

ASTM D 974

0,025

EN-ISO 12205

400

CEC F-06-A-96

Parameter

Unit

Test Method

Minimum maximum

Limits (1)

FAME

prohibited

(1)

The  values  quoted  in  the  specifications  are  “true  values”.  In  establishment  of  their  limit  values  the
terms  of  ISO  4259  “Petroleum  products  –  Determination  and  application  of  precision  data  in  relation  to
methods of test” have been applied and in fixing a minimum value, a minimum difference of 2R above zero has
been  taken  into  account;  in  fixing  a  maximum  and  minimum  value,  the  minimum  difference  is  4R  (R  =
reproducibility).

Notwithstanding  this  measure,  which  is  necessary  for  technical  reasons,  the  manufacturer  of  fuels
should nevertheless aim at a zero value where the stipulated maximum value is 2R and at the mean value in the
case  of  quotations  of  maximum  and  minimum  limits.  Should  it  be  necessary  to  clarify  the  questions  as  to
whether a fuel meets the requirements of the specifications, the terms of ISO 4259 should be applied.

(2)

The range for cetane number is not in accordance with the requirements of a minimum range of 4R.
However, in the case of a dispute between fuel supplier and fuel user, the terms of ISO 4259 may be used to
resolve such disputes provided replicate measurements, of sufficient number to archive the necessary precision,
are made in preference to single determinations.

(3)

(4)

The actual sulphur content of the fuel used for the Type I test shall be reported.

Even though oxidation stability is controlled, it is likely that shelf life will be limited. Advice should

be sought from the supplier as to storage conditions and life.

120

5.

APPENDIX 1 TO ANNEX VII IS REPLACED BY THE FOLLOWING:

“Appendix 1

TEST RESULTS FOR COMPRESSION IGNITION ENGINES

TEST RESULTS

1.

INFORMATION CONCERNING THE CONDUCT OF THE NRSC TEST

1:

1.1.

Reference fuel used for test

1.1.1. Cetane number: ……………………………………………………………..

1.1.2. Sulphur content: …………………………………………………………….

1.1.3. Density ………………………………………………………………………

1.2.

Lubricant

1.2.1. Make(s): ……………………………………………………………………..

1.2.2.Type(s): ………………………………………………………………………

(state percentage of oil in mixture if lubricant and fuel are mixed)

1.3.

Engine driven equipment (if applicable)

1.3.1. Enumeration and identifying details: ………………………………………..

1.3.2. Power absorbed at indicated engine speeds (as specified by the manufacturer):

Power PAE (kW) absorbed at various engine speeds (1), taking  into  account
Appendix 3 of this Annex

Equipment

Intermediate (if applicable)

Rated

Total:

(1) Must not be greater than 10% of the power measured during the test.

1

For the case of several parent engines to be indicated for each of them

121

                                                
1.4.

Engine performance

1.4.1.

Engine speeds:

Idle: . ……………………………………………………………………….…….rpm

Intermediate: ……………………………………………………………………. rpm

Rated: …………………………………………………………………………… rpm

1.4.2.

Engine power1

Condition

Intermediate (if applicable)

Rated

Power setting (kW) at various engine speeds

Maximum power measured on test (PM)

(kW) (a)

Total power absorbed by engine driven equipment as per
section  1.3.2  of  this  Appendix,  or  section  3.1  of  Annex
III (PAE)

(kW) (b)

Net engine power as specified in section 2.4 of Annex I
(kW) (c)

c = a + b

1.5.

Emission levels

1.5.1. Dynamometer setting (kW)

Dynamometer setting (kW) at various engine speeds

Percent Load

Intermediate (if applicable)

Rated

10 (if applicable)

25 (if applicable)

50

75

100

1

Uncorrected power measured in accordance with the provisions of section 2.4 of Annex I.

122

                                                
1.5.2.

Emission results on the NRSC test :

CO: . ……………..g/kWh

HC: . ……………..g/kWh

NOx: . ……………g/kWh

NMHC+NOx: …...g/kWh

Particulates: . ……..g/kWh

1.5.3.

Sampling system used for the NRSC test:

1.5.3.1. Gaseous emissions1:…………………………………………………...

1.5.3.2. Particulates1:……………………………………………………………

1.5.3.2.1.

Method2: single/multiple filter

2.

INFORMATION CONCERNING THE CONDUCT OF THE NRTC TEST

3:

2.1.

Emission results on the NRTC test:

CO: . ……………..g/kWh

NMHC: …………..g/kWh

NOx: . ……………g/kWh

Particulates: . ……..g/kWh

NMHC+NOx : ……g/kWh

2.2.

Sampling system used for the NRTC test:

Gaseous emissions(1):…………………………………………………...

Particulates(1):……………………………………………………………

Method(2): single/multiple filter

1

2

3

Indicate figure numbers defined in Annex VI section 1
Delete as appropriate
For the case of several parent engines to be indicated for each of them

123

                                                
6.

ANNEX XII IS AMENDED AS FOLLOWS:

- a new paragraph 3 is added as follows:

3.

For engines categories H, I, and J (stage IIIA) and engines category K, L and
M (stage IIIB) as defined in Article 9 section 3, the following type-approvals
and, where applicable, the  pertaining  approval  marks  are  recognised  as  being
equivalent to an approval to this Directive;

3.1 Type-approvals  to  Directive  88/77/EEC  as  amended  by  Directive  99/96/EC
which are in compliance with stages B1, B2 or C provided for in Article 2 and
section 6.2.1 of Annex I.

3.2 UN-ECE Regulation 49.03 series of amendments which are in compliance with

stages B1, B2 and C provided for in paragraph 5.2.

“Annex VI

ANNEX II

ANALITYCAL AND SAMPLING SYSTEM

1.

GASEOUS AND PARTICULATE SAMPLING SYSTEMS

Figure Number Description

2

3

4

5

6

7

8

9

10

11

12

13

14

15

Exhaust gas analysis system for raw exhaust

Exhaust gas analysis system for dilute exhaust

Partial flow, isokinetic flow, suction blower control, fractional sampling

Partial flow, isokinetic flow, pressure blower control, fractional sampling

Partial flow, CO2 or NOx control, fractional sampling

Partial flow, CO2 or carbon balance, total sampling

Partial flow, single venturi and concentration measurement, fractional sampling

Partial flow, twin venturi or orifice and concentration measurement, fractional sampling

Partial flow, multiple tube splitting and concentration measurement, fractional sampling

Partial flow, flow control, total sampling

Partial flow, flow control, fractional sampling

Full flow, positive displacement pump or critical flow venturi, fractional sampling

Particulate sampling system

Dilution system for full flow system

124

1.1.

Determination of the gaseous emissions

Section 1.1.1 and Figures 2 and 3 contain detailed descriptions of the recommended sampling
and  analysing  systems.  Since  various  configurations  can  produce  equivalent  results,  exact
conformance with these figures is not required. Additional components such as instruments,
valves,  solenoids,  pumps  and  switches  may  be  used  to  provide  additional  information  and
coordinate the functions of the component systems. Other components which are not needed
to maintain the accuracy on some systems, may be excluded if their exclusion is based upon
good engineering judgement.

1.1.1. Gaseous exhaust components CO, CO2, HC, NOx

An  analytical  system  for  the  determination  of  the  gaseous  emissions  in  the  raw  or  diluted
exhaust gas is described based on the use of:

-

-

-

HFID analyser for the measurement of hydrocarbons,

NDIR analysers for the measurement of carbon monoxide and carbon dioxide,

HCLD or equivalent analyser for the measurement of nitrogen oxide.

For the raw exhaust gas (see Figure 2), the sample for all components may be taken with one
sampling probe or with two sampling probes located in close proximity and internally split to
the  different  analysers.  Care  must  be  taken  that  no  condensation  of  exhaust  components
(including water and sulphuric acid) occurs at any point of the analytical system.

For the diluted exhaust gas (see Figure 3), the sample for the hydrocarbons shall be taken with
another sampling probe than the sample for the other components. Care must be taken that no
condensation of exhaust components (including water and sulphuric acid) occurs at any point
of the analytical system.

125

Figure 2

Flow diagram of exhaust gas analysis system for CO, NOx and HC

HSL1

zero gas

T1

HSL1

T2

G1

zero gas

V1

zero gas

SP1

F1

F2

P

span gas

R3

V1

F1

F2

P

optional 2 sampling probes

SL

vent

HC

R1

R2

vent

air

fuel

FL1

T5
T5

G3 

zero gas

B

V11

V4

span gas

zero gas

V13 V12

V5
span gas

zero gas

R5

V6
span gas

CO

CO

2

O

2

HSL2

T3

G2

V9

zero gas

V7

V3

span gas

R4

C

T4

vent

FL5

vent

FL6

vent

FL7

vent

V8

V10

vent

FL4

NO

T5

vent

FL2

FL8

V13 V12

126

Flow diagram of dilute exhaust gas analysis system for CO, CO2, NOx and HC

Figure 3

to PSS see figure 14

HSL1

T1

HSL1

T2

G1

zero gas

F1

T1

F2

P

HSL2

span gas

R3

F1

F2

P

BK

SL

vent

HC

R1

R2

vent

air

fuel

FL1

PSP

same plane

BK

V1

see fig. 14

zero gas

see fig. 13

V1

V14

SP2

SP2

DT

BG

T5

G3

zero gas

vent

FL5

vent

T3

G2

zero gas

FL6

span gas

V7

V3

R4

V9

C

T4

vent

FL3

V8

V10

vent

vent

FL4

NO

FL2

B

V11

V13 V12

R5

CO

CO
2

V4
span gas
zero gas

V5
span gas

Descriptions - Figures 2 and 3

General statement:

All components in the sampling gas path must be maintained at the temperature specified for
the respective systems.

-

SP1 raw exhaust gas sampling probe (Figure 2 only)

A  stainless  steel  straight  closed  and  multihole  probe  is  recommended.  The  inside  diameter
shall not be greater than the inside diameter of the sampling line. The  wall thickness of the
probe  shall  not  be  greater  than  1  mm.  There  shall  be  a  minimum  of  three  holes  in  three
different radial planes sized to sample approximately the same flow. The probe must extend
across at least 80 % of the diameter of the exhaust pipe.

-

SP2 dilute exhaust gas HC sampling probe (Figure 3 only)

The probe shall:

-

-

be  defined  as  the  first  254  mm  to  762  mm  of  the  hydrocarbon  sampling  line
(HSL3),

have a 5 mm minimum inside diameter,

127

-

-

-

be  installed  in  the  dilution  tunnel  DT  (section  1.2.1.2)  at  a  point  where  the
dilution  air  and  exhaust  gas  are  well  mixed  (i.e.  approximately  10  tunnel
diameters  downstream  of  the  point  where  the  exhaust  enters  the  dilution
tunnel),

be sufficiently distant (radially) from other probes and the tunnel wall so as to
be free from the influence of any wakes or eddies,

be heated so as to increase the gas stream temperature to 463 K (190 °C) ± 10
K at the exit of the probe.

-

SP3 dilute exhaust gas CO, CO2, NOx sampling probe (Figure 3 only)

The probe shall:

-

-

-

be in the same plane as SP2,

be sufficiently distant (radially) from other probes and the tunnel wall so as to
be free from the influence of any wakes or eddies,

be heated and insulated over its entire length to a minimum temperature of 328
K (55 °C) to prevent water condensation.

-

HSL1 heated sampling line

The sampling line provides gas sampling from a single probe to the split point(s) and
the HC analyser.

The sampling line shall:

-

-

-

-

-

have a 5 mm minimum and a 13,5 mm maximum inside diameter,

be made of stainless steel or PTFE,

maintain  a  wall  temperature  of  463  (190  °C)  ±  10  K  as  measured  at  every
separately controlled heated section, if the temperature of the exhaust gas at the
sampling probe is equal or below 463 K (190 °C),

maintain a wall temperature greater than 453 K (180 °C) if the temperature of
the exhaust gas at the sampling probe is above 463 K (190 °C),

maintain a gas temperature of 463 K (190 °C) ± 10 K immediately before the
heated filter (F2) and the HFID.

-

HSL2 heated NOx sampling line

The sampling line shall:

-

-

maintain a wall temperature of 328 to 473 K (55 to 200 °C) up to the converter
when using a cooling bath, and up to the analyser when a cooling bath is not
used,

be made of stainless steel or PTFE.

128

Since  the  sampling  line  need  only  be  heated  to  prevent  condensation  of  water  and
sulphuric  acid,  the  samplingline  temperature  will  depend  on  the  sulphur  content  of
the fuel.

-

SL sampling line for CO (CO2)

The line shall be made of PTFE or stainless steel. It may be heated or unheated.

-

-

-

-

-

-

-

-

-

-

BK background bag (optional; Figure 3 only)

For the measurement of the background concentrations.

BG sample bag (optional; Figure 3 CO and CO2 only)

For the measurement of the sample concentrations.

F1 heated pre-filter (optional)

The temperature shall be the same as HSL1.

F2 heated filter

The filter shall extract any solid particles from the gas sample prior to the analyser.
The temperature shall be the same as HSL1. The filter shall be changed as needed.

P heated sampling pump

The pump shall be heated to the temperature of HSL1.

HC

Heated flame ionization detector (HFID) for the determination of the hydrocarbons.
The temperature shall be kept at 453 to 473 K (180 to 200 °C).

CO, CO2

NDIR analysers for the determination of carbon monoxide and carbon dioxide.

NO2

(H)CLD analyser for the determination of the oxides of nitrogen. If a HCLD is used
it shall be kept at a temperature of 328 to 473 K (55 to 200 °C).

C converter

A converter shall be used for the catalytic reduction of NO2 to NO prior to analysis
in the CLD or HCLD.

B cooling bath

To cool and condense water from the exhaust sample. The bath shall be maintained
at a temperature of 273 to 277 K (0 to 4 °C) by ice or refrigeration. It is optional if
the  analyser  is  free  from  water  vapour  interference  as  determined  in  Annex  III,
Appendix 2, sections 1.9.1 and 1.9.2.

129

-

-

-

-

-

-

-

-

-

-

-

-

-

Chemical dryers are not allowed for removing water from the sample.

T1, T2, T3 temperature sensor

To monitor the temperature of the gas stream.

T4 temperature sensor

Temperature of the NO2-NO converter.

T5 temperature sensor

To monitor the temperature of the cooling bath.

G1, G2, G3 pressure gauge

To measure the pressure in the sampling lines.

R1, R2 pressure regulator

To control the pressure of the air and the fuel, respectively, for the HFID.

R3, R4, R5 pressure regulator

To control the pressure in the sampling lines and the flow to the analysers.

FL1, FL2, FL3 flow-meter

To monitor the sample bypass flow.

FL4 to FL7 flowmeter (optional)

To monitor the flow rate through the analysers.

V1 to V6 selector valve

Suitable valving for selecting sample, span gas or zero gas flow to the analyser.

V7, V8 solenoid valve

To bypass the NO2-NO converter.

V9 needle valve

To balance the flow through the NO2-NO converter and the bypass.

V10, V11 needle valve

To regulate the flows to the analysers.

V12, V13 toggle valve

To drain the condensate from the bath B.

130

-

V14 selector valve

Selecting the sample or background bag.

1.2.

Determination of the particulates

Sections 1.2.1 and 1.2.2 and Figures 4 to 15 contain detailed descriptions of the recommended
dilution and sampling  systems.  Since  various  configurations  can  produce  equivalent  results,
exact  conformance  with  these  figures  is  not  required.  Additional  components  such  as
instruments,  valve,  solenoids,  pumps  and  switches  may  be  used  to  provide  additional
information and coordinate the functions of the component systems. Other components which
are not needed to maintain the accuracy on some systems, may be excluded if their exclusion
is based on good engineering judgement.

1.2.1. Dilution system

1.2.1.1. Partial flow dilution system (Figures 4 to 12)1

A dilution system is described based on the dilution of a part of the exhaust stream. Splitting
of  the  exhaust  stream  and  the  following  dilution  process  may  be  done  by  different  dilution
system  types.  For  subsequent  collection  of  the  particulates,  the  entire  dilute  exhaust  gas  or
only  a  portion  of  the  dilute  exhaust  gas  may  be  passed  to  the  particulate  sampling  system
(section 1.2.2, Figure 14). The first method is referred to as  total sampling type, the second
method as fractional sampling type.

The calculation of the dilution ratio depends on the type of system used.

The following types are recommended:

-

isokinetic systems (Figures 4 and 5)

With  these  systems,  the  flow  into  the  transfer  tube  is  matched  to  the  bulk  exhaust  flow  in
terms of gas velocity and/or pressure, thus requiring an undisturbed and uniform exhaust flow
at the sampling probe. This is usually achieved by using a resonator and a straight approach
tube upstream of the sampling point. The split ratio is then calculated from easily measurable
values  like  tube  diameters.  It  should  be  noted  that  isokinesis  is  only  used  for  matching  the
flow  conditions  and  not  for  matching  the  size  distribution.  The  latter  is  typically  not
necessary, as the particles are sufficiently small as to follow the fluid streamlines,

-

flow controlled systems with concentration measurement (Figures 6 to 10)

With these systems, a sample is taken from the bulk exhaust stream by adjusting the dilution
air  flow  and  the  total  dilution  exhaust  flow.  The  dilution  ratio  is  determined  from  the
concentrations  of  tracer  gases,  such  as  CO2  or  NOx,  naturally  occurring  in  the  engine
exhaust. The concentrations in the dilution exhaust gas and in the dilution air are measured,
whereas  the  concentration  in  the  raw  exhaust  gas  can  be  either  measured  directly  or
determined from fuel flow and the carbon balance equation, if the fuel composition is known.

1

Figures 4 to 12 show many types of partial flow dilution systems, which normally can be used for the steady-state
test (NRSC). But, because of very severe constraints of the transient tests, only those partial flow dilution systems
(Figures  4  to  12)  able  to  fulfill  all  the  requirements  quoted  in  the  section  “Partial  flow  dilution  system
specifications” of Annex III, Appendix 1, Paragraph 2.4, are accepted for the transient test (NRTC).

131

                                                
The  systems  may  be  controlled  by  the  calculated  dilution  ratio  (Figures  6  and  7)  or  by  the
flow into the transfer tube (Figures 8, 9 and 10),

-

flow controlled systems with flow measurement (Figures 11 and 12)

With these systems, a sample is taken from the bulk exhaust stream by setting the dilution air
flow and the total dilution exhaust flow. The dilution ratio is determined from the difference
of  the  two  flow  rates.  Accurate  calibration  of  the  flow-meters  relative  to  one  another  is
required, since the relative magnitude of the  two  flow  rates  can  lead  to  significant  errors  at
higher dilution ratios (Figures 9 and above). Flow control is very straightforward by keeping
the dilute exhaust flow rate constant and varying the dilution air flow rate, if needed.

In order to realize the advantages of the partial flow dilution systems, attention must be paid
to avoiding the potential problems of loss of particulates in the transfer tube, ensuring that a
representative sample is taken from the engine exhaust, and determination of the split ratio.

The systems described pay attention to these critical areas.

Figure 4

Partial flow dilution system with isokinetic probe and fractional sampling (SB control)

DAF

PB

FM1

l > 10*d

SB

air

PSP

d

DT

PTT

vent

TT

see figure 14

to particulate
sampling
system

ISP

EP

DPT
delta p

exhaust

FC1

Raw exhaust gas is transferred from the exhaust pipe to EP to the dilution tunnel DT through
the  transfer  tube  TT  by  the  isokinetic  sampling  probe  ISP.  The  differential  pressure  of  the
exhaust  gas  between  exhaust  pipe  and  inlet  to  the  probe  is  measured  with  the  pressure
transducer DPT. This signal is transmitted to the flow controller FC1 that controls the suction
blower  SB  to  maintain  a  differential  pressure  of  zero  at  the  tip  of  the  probe.  Under  these
conditions, exhaust gas velocities in EP and ISP are identical, and the flow through ISP and
TT is a constant fraction (split) of the exhaust gas flow. The split ratio is determined from the
cross  sectional  areas  of  EP  and  ISP.  The  dilution  air  flow  rate  is  measured  with  the  flow
measurement device FM1. The dilution ratio is calculated from the dilution air flow rate and
the split ratio.

132

Figure 5

Partial flow dilution system with isokinetic probe and fractional sampling (PB control)

DAF

FM1

l > 10*d

PSP

d

SB

vent

air

ISP

EP

TT

DT

PTT

see figure 14

to particulate
sampling
system

PB

exhaust

DPT
delta p

FC1

Raw exhaust gas is transferred from the exhaust pipe EP to the dilution tunnel DT through the
transfer tube TT by the isokinetic sampling probe ISP. The differential pressure of the exhaust
gas  between  exhaust  pipe  and  inlet  to  the  probe  is  measured  with  the  pressure  transducer
DPT. This signal is transmitted to the flow controller  FC1 that controls the pressure blower
PB to maintain a differential pressure of zero at the tip of the probe. This is done by taking a
small  fraction  of  the  dilution  air  whose  flow  rate  has  already  been  measured  with  the  flow
measurement device FM1, and feeding it to TT by means of a pneumatic orifice. Under these
conditions, exhaust gas velocities in EP and ISP are identical, and the flow through ISP and
TT is a constant fraction (split) of the exhaust gas flow. The split ratio is determined from the
cross  sectional  areas  of  EP  and  ISP.  The  dilution  air  is  sucked  through  DT  by  the  suction
blower SB, and the flow rate is measured with FM1 at the inlet to DT. The dilution ratio is
calculated from the dilution air flow rate and the split ratio.

133

Figure 6

Partial flow dilution system with CO2 or NOx concentration measurement
and fractional sampling

FC2

EGA

DAF

optional

to PB or SB

EGA

l > 10*d

SB

d

DT

PSP

PTT

vent

TT

see figure 14

to particulate
sampling
system

air

EGA

PB

EP

SP

exhaust

Raw exhaust gas is transferred from the exhaust pipe EP to the dilution tunnel DT through the
sampling probe SP and the transfer tube TT. The concentrations of a tracer gas (CO2 or NOx)
are measured in the raw and diluted exhaust gas as well as in the dilution air with the exhaust
gas  analyser(s)  EGA.  These  signals  are  transmitted  to  the  flow  controller  FC2  that  controls
either the pressure blower PB or the suction blower SB to maintain the desired exhaust split
and dilution ratio in DT. The dilution ratio is calculated from the tracer gas concentrations in
the raw exhaust gas, the diluted exhaust gas, and the dilution air.

134

Figure 7

Partial flow dilution system with CO2 concentration measurement, carbon balance
and total sampling

FC2

EGA

optional to P

DAF

d

DT

TT

SP

optional from FC2

air

G FUEL

PB

EP

exhaust

EGA

PTT

PSS

FH

P

details see figure 15

Raw exhaust gas is transferred from the exhaust pipe EP to the dilution tunnel DT through the
sampling  probe  SP  and  the  transfer  tube  TT.  The  CO2  concentrations  are  measured  in  the
diluted exhaust gas and in the dilution air with the exhaust gas analyser(s) EGA. The CO2 and
fuel  flow  GFUEL  signals  are  transmitted  either  to  the  flow  controller  FC2,  or  to  the  flow
controller FC3 of the particulate sampling system (see Figure 14). FC2 controls the pressure
blower  PB,  while  FC3  controls  the  particulate  sampling  system  (see  Figure  14),  thereby
adjusting the flows into and out of the system so as to maintain the desired exhaust split and
dilution ratio in DT. The dilution ratio is calculated from the CO2 concentrations and GFUEL
using the carbon balance assumption.

135

Figure 8

Partial flow dilution system with single venturi, concentration measurement
and fractional sampling

EGA

EGA

DAF

PB

l > 10*d

air

VN

d

PSP

DT

PTT

vent

TT

see figure 14

to particulate
sampling
system

SP

EP

EGA

exhaust

Raw exhaust gas is transferred from the exhaust pipe EP to the dilution tunnel DT through the
sampling  probe  SP  and  the  transfer  tube  TT  due  to  the  negative  pressure  created  by  the
venturi VN in DT. The gas flow rate through TT depends on the momentum exchange at the
venturi zone, and is therefore affected by the absolute temperature of the gas at the exit of TT.
Consequently, the exhaust split for a given tunnel flow rate is not constant, and the dilution
ratio  at  low  load  is  slightly  lower  than  at  high  load.  The  tracer  gas  concentrations  (CO2  or
NOx) are measured in the raw exhaust gas, the diluted exhaust gas, and the dilution air with
the  exhaust  gas  analyser(s)  EGA,  and  the  dilution  ratio  is  calculated  from  the  values  so
measured.

136

Figure 9

Partial flow dilution system twin venturi or twin orifice, concentration measurement
and fractional sampling

EGA

EGA

DAF

PCV2

l > 10*d

HE

d

DT

PSP

PTT

TT

see figure 14

to particulate
sampling

system

SB

vent

PB

PCV1

air

EP

FD1

FD2

exhaust

EGA

Raw exhaust gas is transferred from the exhaust pipe EP to the dilution tunnel DT through the
sampling probe SP and the transfer tube TT by a flow divider that contains a set of orifices or
venturis. The first one (FD1) is located in EP, the second one (FD2) in TT. Additionally, two
pressure control valves (PCV1 and PCV2) are necessary to maintain a constant exhaust split
by controlling the backpressure in EP and the pressure in DT. PCV1 is located downstream of
SP in EP, PCV2 between the pressure blower PB and DT. The tracer gas concentrations (CO2
or  NOx)  are  measured  in  the  raw  exhaust  gas,  the  diluted  exhaust  gas,  and  the  dilution  air
with the exhaust gas analyser(s) EGA. They are necessary for checking the exhaust split, and
may  be  used  to  adjust  PCV1  and  PCV2  for  precise  split  control.  The  dilution  ratio  is
calculated from the tracer gas oncentrations.

137

Figure 10

Partial flow dilution system with multiple tube splitting, concentration measurement
and fractional sampling

EGA

EGA

DAF

air

fresh air injection

EGA

TT

FD3

EP

l > 10*d

DT

d

see figure 14

HE

PSP
PTT

SB

to particulate
sampling
system

FC1

DPT

DC

DAF

vent

air

Raw exhaust gas is transferred from the exhaust pipe EP to the dilution tunnel DT through the
transfer  tube  TT  by  the  flow  divider  FD3  that  consists  of  a  number  of  tubes  of  the  same
dimensions (same diameter, length and bed radius) installed in EP. The exhaust gas through
one of these tubes is lead to DT, and the exhaust gas through the rest of the tubes is passed
through the damping chamber DC. Thus, the exhaust split is determined by the total number
of tubes. A constant split control requires a differential pressure of zero between DC and the
outlet of TT, which is measured with the differential pressure transducer DPT. A differential
pressure of zero is achieved by injecting fresh air into DT at the outlet of TT. The tracer gas
concentrations (CO2 or NOx) are measured in the raw exhaust gas, the diluted exhaust gas,
and the dilution air with the exhaust gas analyser(s) EGA.  They  are  necessary  for  checking
the exhaust split and may be used to control the injection air flow rate for precise split control.
The dilution ratio is calculated from the tracer gas concentrations.

138

Figure 11

Partial flow dilution system with flow control and total sampling

FC2

DAF

optional to P (PSS)

d

DT

FM1

TT

GEXH

or
GAIR
or
GFUEL

SP

EP

exhaust

PTT

FH

vent

PSS

P

details see figure 15

Raw exhaust gas is transferred from the exhaust pipe EP to the dilution tunnel DT through the
sampling probe SP and the transfer tube TT. The total flow through the tunnel is adjusted with
the  flow  controller  FC3  and  the  sampling  pump  P  of  the  particulate  sampling  system  (see
Figure 16)

The dilution air flow is controlled by the flow controller FC2, which may use GEXH, GAIR or
GFUEL  as  command  signals,  for  the  desired  exhaust  split.  The  sample  flow  into  DT  is  the
difference of the total flow and the dilution air flow. The dilution air flow rate is  measured
with  flow  measurement  device  FM1,  the  total  flow  rate  with  the  flow  measurement  device
FM3 of the particulate sampling system (see Figure 14). The dilution ratio is calculated from
these two flow rates.

139

Figure 12

Partial flow dilution system with flow control and fractional sampling

FC2

to PB
or SB

DAF

air

PB

FM1

GEXH

or
GAIR
or
GFUEL

SP

EP

exhaust

l > 10*d

SB

DT

d

PSP

TT

see figure 14

PTT

to particulate
sampling
system

see figure 14

FM2

vent

Raw exhaust gas is transferred from the exhaust pipe EP to the dilution tunnel DT through the
sampling  probe  SP  and  the  transfer  tube  TT.  The  exhaust  split  and  the  flow  into  DT  is
controlled by the flow controller FC2 that adjusts the flows (or speeds) of the pressure blower
PB and the suction blower SB, accordingly. This is possible since the sample taken with the
particulate  sampling  system  is  returned  into  DT.  GEXH,  GAIR  or  GFUEL  may  be  used  as
command signals for FC2. The dilution air flow rate is measured with the flow measurement
device  FM1,  the  total  flow  with  the  flow  measurement  device  FM2.  The  dilution  ratio  is
calculated from these two flow rates.

Description - Figures 4 to 12

-

EP exhaust pipe

The exhaust pipe may be insulated. To reduce the thermal inertia of the exhaust pipe
a  thickness  to  diameter  ratio  of  0,015  or  less  is  recommended.  The  use  of  flexible
sections  shall  be  limited  to  a  length  to  diameter  ratio  of  12  or  less.  Bends  will  be
minimized to reduce inertial deposition. If the system includes a test bed silencer, the
silencer may also be insulated.

For an isokinetic system, the exhaust pipe must be free of elbows, bends and sudden
diameter  changes  for  at  least  six  pipe  diameters  upstream  and  three  pipe  diameters
downstream of the tip of the probe. The  gas velocity  at the sampling zone must be
higher than 10 m/s except at idle mode. Pressure oscillations of the exhaust gas must
not exceed ± 500 Pa on the average. Any steps to reduce pressure oscillations beyond
using  a  chassis-type  exhaust  system  (including  silencer  and  after-treatment  device)
must not alter engine performance nor cause the deposition of particulates.

140

For systems without isokinetic probes, it is recommended to have a straight pipe of
six  pipe  diameters  upstream  and  three  pipe  diameters  downstream  of  the  tip  of  the
probe.

-

SP sampling probe (Figures 6 to 12)

The minimum inside diameter shall be 4 mm. The minimum diameter ratio between
exhaust  pipe  and  probe  shall  be  four.  The  probe  shall  be  an  open  tube  facing
upstream on the exhaust pipe centre-line, or a multiple hole probe as described under
SP1 in section 1.1.1.

-

ISP isokinetic sampling probe (Figures 4 and 5)

The isokinetic sampling probe must be installed facing upstream on the exhaust pipe
centre-line where the flow conditions in section EP are met, and designed to provide
a proportional sample of the raw exhaust gas. The minimum inside diameter shall be
12 mm.

A  control  system  is  necessary  for  isokinetic  exhaust  splitting  by  maintaining  a
differential pressure of zero between EP and ISP. Under these conditions exhaust gas
velocities  in  EP  and  ISP  are  identical  and  the  mass  flow  through  ISP  is  a  constant
fraction  of  the  exhaust  gas  flow.  The  ISP  has  to  be  connected  to  a  differential
pressure transducer. The control to provide a differential pressure of zero between EP
and ISP is done with blower speed or flow controller.

-

FD1, FD2 flow divider (Figure 9)

A set of venturis or orifices is installed in the exhaust pipe EP and in the transfer tube
TT, respectively, to provide a proportional sample of the raw exhaust gas. A control
system  consisting  of  two  pressure  control  valves  PCV1  and  PCV2  is  necessary  for
proportional splitting by controlling the pressures in EP and DT.

-

FD3 flow divider (Figure 10)

A  set  of  tubes  (multiple  tube  unit)  is  installed  in  the  exhaust  pipe  EP  to  provide  a
proportional sample of the raw exhaust gas. One of the tubes feeds exhaust gas to the
dilution tunnel DT, whereas the other tubes exit exhaust gas to a damping chamber
DC. The tubes must have the same dimensions (same diameter, length, bend radius),
so that the exhaust split depends on  the  total  number  of  tubes.  A  control  system  is
necessary  for  proportional  splitting  by  maintaining  a  differential  pressure  of  zero
between the exit of the multiple tube unit into DC and the exit of TT. Under these
conditions, exhaust gas velocities in EP and FD3 are proportional, and the flow TT is
a constant fraction of the exhaust gas flow. The two points have to be connected to a
differential pressure transducer DPT. The control to provide a differential pressure of
zero is done with the flow controller FC1.

-

EGA exhaust gas analyser (Figures 6 to 10)

CO2  or  NOx  analysers  may  be  used  (with  carbon  balance  method  CO2  only).  The
analysers  shall  be  calibrated  like  the  analysers  for  the  measurement  of  the  gaseous
emissions.  One  or  several  analysers  may  be  used  to  determine  the  concentration
differences.

141

The accuracy of the measuring systems has to be such that the accuracy of GEDFW,i is
within ± 4 %.

-

TT transfer tube (Figures 4 to 12)

The particulate sample transfer tube shall be:

-

as short as possible, but not more than 5 m in length,

equal to or greater than the probe diameter, but not more than 25 mm in

-
diameter,

exiting  on  the  centre-line  of  the  dilution  tunnel  and  pointing  down-

-
stream.

If  the  tube  is  1  metre  or  less  in  length,  it  is  to  be  insulated  with  material  with  a
maximum thermal conductivity of 0,05 W/(m · K) with a radial insulation thickness
corresponding to the diameter of the probe. If the tube is longer than 1 metre, it must
be insulated and heated to a minimum wall temperature of 523 K (250 °C).

Alternatively,  the  transfer  tube  wall  temperatures  required  may  be  determined
through standard heat transfer calculations.

-

DPT differential pressure transducer (Figures 4, 5 and 10)

The differential pressure transducer shall have a range of ± 500 Pa or less.

-

FC1 flow controller (Figures 4, 5 and 10)

For  the  isokinetic  systems  (Figures  4  and  5)  a  flow  controller  is  necessary  to
maintain a differential pressure of zero between EP and ISP. The adjustment can be
done by:

controlling the speed or flow of the suction blower (SB) and keeping the speed

a)
of the pressure blower (PB) constant during each mode (Figure 4);

or

b)
adjusting  the  suction  blower  (SB)  to  a  constant  mass  flow  of  the  diluted
exhaust and controlling the flow of the pressure blower PB, and therefore the exhaust
sample flow in a region at the end of the transfer tube (TT) (Figure 5).

In  the  case  of  a  pressure  controlled  system  the  remaining  error  in  the  control  loop
must  not  exceed  ±  3  Pa.  The  pressure  oscillations  in  the  dilution  tunnel  must  not
exceed ± 250 Pa on average.

For  a  multi-tube  system  (Figure  10)  a  flow  controller  is  necessary  for  proportional
exhaust splitting to maintain a differential pressure of zero between the outlet of the
multi-tube  unit  and  the  exit  of  TT.  The  adjustment  can  be  done  by  controlling  the
injection air flow rate into DT at the exit of TT.

142

-

PCV1, PCV2 pressure control valve (Figure 9)

Two  pressure  control  valves  are  necessary  for  the  twin  venturi/twin  orifice  system
for proportional flow splitting by controlling the backpressure of EP and the pressure
in DT. The valves shall be located downstream of SP in EP and between PB and DT.

-

DC damping chamber (Figure 10)

A  damping  chamber  shall  be  installed  at  the  exit  of  the  multiple  tube  unit  to
minimize the pressure oscillations in the exhaust pipe EP.

-

VN venturi (Figure 8)

A venturi is  installed  in  the  dilution  tunnel  DT  to  create  a  negative  pressure  in  the
region of the exit of the transfer tube TT. The gas flow rate through TT is determined
by the momentum exchange at the venturi zone, and is basically proportional to the
flow  rate  of  the  pressure  blower  PB  leading  to  a  constant  dilution  ratio.  Since  the
momentum exchange is affected by the temperature at the exit of TT and the pressure
difference between EP and DT, the actual dilution ratio is slightly lower at low load
than at high load.

-

FC2 flow controller (Figures 6, 7, 11 and 12; optional)

A flow controller may be used to control the flow of the pressure blower PB and/or
the suction blower SB. It may be connected to the exhaust flow or fuel flow signal
and/or to the CO2 or NOx differential signal.

When using a pressurized air supply (Figure 11) FC2 directly controls the air flow.

-

FM1 flow measurement device (Figures 6, 7, 11 and 12)

Gas  meter  or  other  flow  instrumentation  to  measure  the  dilution  air  flow.  FM1  is
optional if PB is calibrated to measure the flow.

-

FM2 flow measurement device (Figure 12)

Gas  meter  or  other  flow  instrumentation  to  measure  the  diluted  exhaust  gas  flow.
FM2 is optional if the suction blower SB is calibrated to measure the flow.

-

PB pressure blower (Figures 4, 5, 6, 7, 8, 9 and 12)

To  control  the  dilution  air  flow  rate,  PB  may  be  connected  to  the  flow  controllers
FC1  or  FC2.  PB  is  not  required  when  using  a  butterfly  valve.  PB  may  be  used  to
measure the dilution air flow, if calibrated.

-

SB suction blower (Figures 4, 5, 6, 9, 10 and 12)

For fractional sampling systems only. SB may be used to measure the dilute exhaust
gas flow, if calibrated.

-

DAF dilution air filter (Figures 4 to 12)

143

It is recommended that the dilution air be filtered and charcoal scrubbed to eliminate
background hydrocarbons. The dilution air shall have a temperature of 298 K (25 °C)
± 5 K.

At  the  manufacturer's  request  the  dilution  air  shall  be  sampled  according  to  good
engineering practice to determine the background particulate levels, which can then
be subtracted from the values measured in the diluted exhaust.

-

PSP particulate sampling probe (Figures 4, 5, 6, 8, 9, 10 and 12)

The probe is the leading section of PTT and

-

-

-

-

shall  be  installed  facing  upstream  at  a  point  where  the  dilution  air  and
exhaust gas are well mixed, i.e. on the dilution tunnel DT centre-line of
the  dilution  systems  approximately  10  tunnel  diameters  downstream  of
the point where the exhaust enters the dilution tunnel,

shall be 12 mm in minimum inside diameter,

may  be  heated  to  no  greater  than  325  K  (52  °C)  wall  temperature  by
direct heating or by dilution air pre-heating, provided the air temperature
does not exceed 325 K (52 °C) prior to the introduction of the exhaust in
the dilution tunnel,

may be insulated.

-

DT dilution tunnel (Figures 4 to 12)

The dilution tunnel:

-

-

-

-

-

-

shall  be  of  a  sufficient  length  to  cause  complete  mixing  of  the  exhaust
and dilution air under turbulent flow conditions,

shall be constructed of stainless steel with:

-

-

a thickness to diameter ratio of 0,025 or less for dilution tunnels of
greater than 75 mm inside diameter,

a  nominal  wall  thickness  of  not  less  than  1,5  mm  for  dilution
tunnels of equal to or less than 75 mm inside diameter,

shall be at least 75 mm in diameter for the fractional sampling type,

is recommended to be at least 25 mm in diameter for the total sampling
type.

may  be  heated  to  no  greater  than  325  K  (52  °C)  wall  temperature  by
direct heating or by dilution air pre-heating, provided the air temperature
does not exceed 325 K (52 °C) prior to the introduction of the exhaust in
the dilution tunnel.

may be insulated.

144

The engine exhaust shall be thoroughly mixed with the dilution air. For fractional sampling
systems, the mixing quality shall be checked after introduction into service by means of a CO2
profile of the tunnel with the engine running (at least four equally spaced measuring points).
If necessary, a mixing orifice may be used.

Note:

If the ambient temperature in the vicinity of the dilution tunnel (DT) is below 293 K
(20 °C), precautions should be taken to avoid particle losses onto the cool walls of
the dilution tunnel. Therefore, heating and/or insulating the tunnel within the limits
given above is recommended.

At  high  engine  loads,  the  tunnel  may  be  cooled  by  a  non-aggressive  means  such  as  a
circulating fan, as long as the temperature of the cooling medium is not below 293 K (20 °C).

-

HE heat exchanger (Figures 9 and 10)

The heat exchanger shall be of sufficient capacity to maintain the temperature at the inlet to
the suction blower SB within ± 11 K of the  average operating  temperature  observed  during
the test.

1.2.1.2. Full flow dilution system (Figure 13)

A dilution system is described based upon the dilution of the total exhaust using the constant
volume sampling (CVS) concept. The total volume of the mixture of exhaust and dilution air
must be measured. Either a PDP or a CFV or a SSV system may be used.

For subsequent collection of the particulates, a sample of the dilute exhaust gas is passed to
the particulate sampling system (section 1.2.2, Figures 14 and 15). If this is done directly, it is
referred  to  as  single  dilution.  If  the  sample  is  diluted  once  more  in  the  secondary  dilution
tunnel,  it  is  referred  to  as  double  dilution.  This  is  useful,  if  the  filter  face  temperature
requirement cannot be met with single dilution. Although partly a dilution system, the double
dilution  system  is  described  as  a  modification  of  a  particulate  sampling  system  in  section
1.2.2, Figure 15, since it shares most of the parts with a typical particulate sampling system.

The gaseous emissions may also be determined in the dilution tunnel of a full flow dilution
system. Therefore, the sampling probes for the gaseous components are shown in Figure 13
but do not appear in the description list. The respective requirements are described in section
1.1.1.

Descriptions - Figure 13

-

EP exhaust pipe

The  exhaust  pipe  length  from  the  exit  of  the  engine  exhaust  manifold,
turbocharger outlet or after-treatment device to the dilution tunnel is  required
to be not more than 10 m. If the system exceeds 4 m in length, then all tubing
in excess of 4 m shall be insulated, except for an in-line smoke-meter, if used.
The  radial  thickness  of  the  insulation  must  be  at  least  25  mm.  The  thermal
conductivity  of  the  insulating  material  must  have  a  value  no  greater  than  0,1
W/(m · K) measured at 673 K  (400  °C).  To  reduce  the  thermal  inertia  of  the
exhaust pipe a thickness to diameter ratio of 0,015 or less is recommended. The
use of flexible sections shall be limited to a length to diameter ratio  of  12  or
less.

145

Figure 13

Full flow dilution system

see Figure 3

to exhaust gas

analysis system

HE

optional

to background filter

DAF

air

exhaust

EP

PSP

PTT

see figure 14

optional

to particulate sampling system
or to DDS see figure 15

PDP

FC3

if EFC is used

FC3

CFV or
SSV

vent

vent

The total amount of raw exhaust  gas is mixed in the dilution  tunnel  DT  with
the  dilution  air.  The  diluted  exhaust  gas  flow  rate  is  measured  either  with  a
positive displacement pump PDP or with a critical flow venturi CFV or with a
sub-sonic venturi SSV. A heat exchanger HE or electronic flow compensation
EFC  may  be  used  for  proportional  particulate  sampling  and  for  flow
determination.  Since  particulate  mass  determination  is  based  on  the  total
diluted exhaust gas flow, the dilution ratio is not required to be calculated.

-

PDP positive displacement pump

The  PDP  meters  total  diluted  exhaust  flow  from  the  number  of  the  pump
revolutions  and  the  pump  displacement.  The  exhaust  system  back  pressure
must not be artificially lowered by the PDP or dilution air inlet system. Static
exhaust  back  pressure  measured  with  the  CVS  system  operating  shall  remain
within ± 1,5 kPa of the static pressure measured without connection to the CVS
at identical engine speed and load.

The gas mixture temperature immediately ahead of the PDP shall be within ± 6
K of the average operating temperature observed during the test, when no flow
compensation is used.

Flow compensation can only be used if the temperature at the inlet of the PDP
does not exceed 50 °C (323 K).

146

-

CFV critical flow venturi

CFV  measures  total  diluted  exhaust  flow  by  maintaining  the  flow  at  choked
conditions (critical flow). Static exhaust backpressure measured with the CFV
system operating shall remain within ± 1,5 kPa of the static pressure measured
without  connection  to  the  CFV  at  identical  engine  speed  and  load.  The  gas
mixture temperature immediately ahead of the CFV shall be within ± 11 K of
the  average  operating  temperature  observed  during  the  test,  when  no  flow
compensation is used.

-

SSV sub-sonic venturi

SSV  measures  total  diluted  exhaust  flow  as  a  function  of  inlet  pressure,  inlet  temperature,
pressure drop between the SSV  inlet  and  throat.  Static  exhaust  backpressure  measured  with
the  SSV  system  operating  shall  remain  within  ±  1,5  kPa  of  the  static  pressure  measured
without  connection  to  the  SSV  at  identical  engine  speed  and  load.  The  gas  mixture
temperature immediately ahead of the SSV shall be within ± 11 K of the average operating
temperature observed during the test, when no flow compensation is used.

-

-

HE heat exchanger (optional if EFC is used)

The heat exchanger shall be of sufficient capacity to maintain the temperature
within the limits required above.

EFC electronic flow compensation (optional if HE is used)

If  the  temperature  at  the  inlet  to  either  the  PDP  or  CFV  or  SSV  is  not  kept
within  the  limits  stated  above,  a  flow  compensation  system  is  required  for
continuous  measurement  of  the  flow  rate  and  control  of  the  proportional
sampling in the particulate system. To that purpose, the continuously measured
flow  rate  signals  are  used  to  correct  the  sample  flow  rate  through  the
particulate  filters  of  the  particulate  sampling  system  (see  Figures  14  and  15),
accordingly.

-

DT dilution tunnel

The dilution tunnel:

-

-

-

shall  be  small  enough  in  diameter  to  cause  turbulent  flow  (Reynolds
number greater than 4000) of sufficient length to cause complete mixing
of the exhaust and dilution air. A mixing orifice may be used,

shall be at least 75 mm in diameter,

may be insulated.

The  engine  exhaust  shall  be  directed  downstream  at  the  point  where  it  is
introduced into the dilution tunnel, and thoroughly mixed.

When using single dilution, a sample from the dilution tunnel is transferred to
the particulate sampling system (section 1.2.2, Figure 14). The flow capacity of
the PDP or CFV or SSV must be sufficient to maintain the diluted exhaust at a

147

temperature  of  less  than  or  equal  to  325  K  (52  °C)  immediately  before  the
primary particulate filter.

When using double dilution, a sample from the dilution tunnel is transferred to
the  secondary  dilution  tunnel  where  it  is  further  diluted,  and  then  passed
through the sampling filters (section 1.2.2, Figure 15). The flow capacity of the
PDP or CFV or SSV must be sufficient to maintain the diluted exhaust stream
in  the  DT  at  a  temperature  of  less  than  or  equal  to  464  K  (191  °C)  at  the
sampling  zone.  The  secondary  dilution  system  must  provide  sufficient
secondary  dilution  air  to  maintain  the  doubly-diluted  exhaust  stream  at  a
temperature  of  less  than  or  equal  to  325  K  (52  °C)  immediately  before  the
primary particulate filter.

-

DAF dilution air filter

It  is  recommended  that  the  dilution  air  be  filtered  and  charcoal  scrubbed  to
eliminate background hydrocarbons. The dilution air shall have a temperature
of 298 K (25 °C) ± 5 K. At the manufacturer's request the dilution air shall be
sampled according  to  good  engineering  practice  to  determine  the  background
particulate  levels,  which  can  then  be  subtracted  from  the  values  measured  in
the diluted exhaust.

-

PSP particulate sampling probe

The probe is the leading section of PTT and

-

-

-

-

shall  be  installed  facing  upstream  at  a  point  where  the  dilution  air  and
exhaust gas are well mixed, i.e. on the dilution tunnel DT centre-line of
the  dilution  systems  approximately  10  tunnel  diameters  downstream  of
the point where the exhaust enters the dilution tunnel,

shall be 12 mm in minimum inside diameter,

may  be  heated  to  no  greater  than  325  K  (52  °C)  wall  temperature  by
direct heating or by dilution air pre-heating, provided the air temperature
does not exceed 325 K (52 °C) prior to the introduction of the exhaust in
the dilution tunnel,

may be insulated.

1.2.2.

Particulate sampling system (Figures 14 and 15)

The particulate sampling system is required for  collecting the particulates on the particulate
filter. In the case of total sampling partial flow dilution, which consists of passing the entire
dilute  exhaust  sample  through  the  filters,  dilution  (section  1.2.1.1,  Figures  7  and  11)  and
sampling system usually form an integral unit. In the case of fractional sampling partial flow
dilution or full flow dilution, which consists of passing through the filters only a portion of
the diluted exhaust, the dilution (section 1.2.1.1, Figures 4, 5, 6, 8, 9, 10 and 12 and section
1.2.1.2, Figure 13) and sampling systems usually form different units.

In this Directive, the double dilution system DDS (Figure 15) of a full flow dilution system is
considered  as  a  specific  modification  of  a  typical  particulate  sampling  system  as  shown  in
Figure 14. The double dilution system includes all important parts of the particulate sampling

148

system, like filter holders and sampling pump, and additionally some dilution features, like a
dilution air supply and a secondary dilution tunnel.

In order to avoid any impact on the control loops, it is recommended that the sample pump be
running throughout the complete test procedure. For the single filter method, a bypass system
shall  be  used  for  passing  the  sample  through  the  sampling  filters  at  the  desired  times.
Interference of the switching procedure on the control loops must be minimized.

Descriptions - Figures 14 and 15

-

PSP particulate sampling probe (Figures 14 and 15)

The particulate sampling probe shown  in  the  figures  is  the  leading  section  of
the particulate transfer tube PTT. The probe:

-

-

-

-

shall  be  installed  facing  upstream  at  a  point  where  the  dilution  air  and
exhaust gas are well mixed, i.e. on the dilution tunnel DT centre-line of
the  dilution  systems  (see  section  1.2.1),  approximately  10  tunnel
diameters downstream of the point where the exhaust enters the dilution
tunnel),

shall be 12 mm in minimum inside diameter,

may  be  heated  to  no  greater  than  325  K  (52  °C)  wall  temperature  by
direct heating or by dilution air pre-heating, provided the air temperature
does not exceed 325 K (52 °C) prior to the introduction of the exhaust in
the dilution tunnel,

may be insulated.

Figure 14

Particulate sampling system

from dilution tunnel DT

see figures 4 to 13

PTT

BV

FH

FC3

P

FM3

optional

from EGA

from PDP

from CFV

or

or

or

from GFUEL

149

A sample of the diluted exhaust gas is taken from the dilution tunnel DT of a partial flow or
full  flow  dilution  system  through  the  particulate  sampling  probe  PSP  and  the  particulate
transfer tube PTT by means of the sampling pump P. The sample is passed through the filter
holders(s) FH that contain the particulate sampling filters. The sample flow rate is controlled
by the flow controller FC3. If electronic flow compensation EFC (see Figure 13) is used, the
diluted exhaust gas flow is used as command signal for FC3.

Figure 15

Dilution system (full flow system only)

FM4

DP

SDT

BV

FH

P

FM3

vent

PTT
BV optional

from dilution
tunnel DT
see figure 13

FC3

PDP
or
CFV

A sample of the diluted exhaust gas is transferred from the dilution tunnel DT of a full flow
dilution system through the particulate sampling probe PSP and the particulate transfer tube
PTT to the secondary dilution tunnel SDT, where it is diluted once more. The sample is then
passed  through  the  filter  holder(s)  FH  that  contain  the  particulate  sampling  filters.  The
dilution  air  flow  rate  is  usually  constant  whereas  the  sample  flow  rate  is  controlled  by  the
flow controller  FC3.  If electronic  flow compensation EFC  (see  Figure  13)  is  used,  the  total
diluted exhaust gas flow is used as command signal for FC3.

-

PTT particulate transfer tube (Figures 14 and 15)

The particulate transfer tube must not exceed 1 020 mm in length, and must be
minimized in length whenever possible.

The dimensions are valid for:

-

-

-

the partial flow dilution fractional sampling type and the full flow single
dilution system from the probe tip to the filter holder,

the partial flow dilution total sampling type from the end of the dilution
tunnel to the filter holder,

the full flow double dilution system from the probe tip to the secondary
dilution tunnel.

The transfer tube:

-

-

may  be  heated  to  no  greater  than  325  K  (52  °C)  wall  temperature  by
direct heating or by dilution air pre-heating, provided the air temperature
does not exceed 325 K (52 °C) prior to the introduction of the exhaust in
the dilution tunnel,

may be insulated.

150

-

SDT secondary dilution tunnel (Figure 15)

The secondary dilution tunnel should have a minimum diameter of 75 mm and
should  be  sufficient  length  so  as  to  provide  a  residence  time  of  at  least  0,25
seconds for the doubly-diluted sample. The primary filter holder, FH, shall be
located within 300 mm of the exit of the SDT.

The secondary dilution tunnel:

-

-

may  be  heated  to  no  greater  than  325  K  (52  °C)  wall  temperature  by
direct heating or by dilution air pre-heating, provided the air temperature
does not exceed 325 K (52 °C) prior to the introduction of the exhaust in
the dilution tunnel,

may be insulated.

-

FH filter holder(s) (Figures 14 and 15)

For  primary  and  back-up  filters  one  filter  housing  or  separate  filter  housings
may be used. The requirements of Annex III, Appendix 1, section 1.5.1.3 have
to be met.

The filter holder(s):

-

-

may  be  heated  to  no  greater  than  325  K  (52  °C)  wall  temperature  by
direct heating or by dilution air pre-heating, provided the air temperature
does not exceed 325 K (52 °C),

may be insulated.

-

-

-

P sampling pump (Figures 14 and 15)

The  particulate  sampling  pump  shall  be  located  sufficiently  distant  from  the
tunnel so that the inlet gas temperature is maintained constant (± 3 K), if flow
correction by FC3 is not used.

DP dilution air pump (Figure 15) (full flow double dilution only)

The  dilution  air  pump  shall  be  located  so  that  the  secondary  dilution  air  is
supplied at a temperature of 298 K (25 °C) ± 5 K.

FC3 flow controller (Figures 14 and 15)

A flow controller shall be used to compensate the particulate sample flow rate
for  temperature  and  backpressure  variations  in  the  sample  path,  if  no  other
means  are  available.  The  flow  controller  is  required  if  electronic  flow
compensation EFC (see Figure 13) is used.

151

-

-

-

FM3 flow measurement device (Figures 14 and 15) (particulate sample
flow)

The gas meter or flow instrumentation shall be located sufficiently distant from
the sample pump so that the inlet gas temperature remains constant (± 3 K), if
flow correction by FC3 is not used.

FM4 flow measurement device (Figure 15) (dilution air, full flow double
dilution only)

The  gas  meter  or  flow  instrumentation  shall  be  located  so  that  the  inlet  gas
temperature remains at 298 K (25 °C) ± 5 K.

BV ball valve (optional)

The  ball  valve  shall  have  a  diameter  not  less  than  the  inside  diameter  of  the
sampling tube and a switching time of less than 0,5 seconds.

Note: If the ambient temperature in the vicinity of PSP, PTT, SDT, and FH is
below 239 K (20 °C), precautions should be taken to avoid particle losses
onto  the  cool  wall  of  these  parts.  Therefore,  heating  and/or  insulating
these  parts  within  the  limits  given  in  the  respective  descriptions  is
recommended.  It  is  also  recommended  that  the  filter  face  temperature
during sampling be not below 293 K (20 °C).

At  high  engine  loads,  the  above  parts  may  be  cooled  by  a  non-aggressive
means  such  as  a  circulating  fan,  as  long  as  the  temperature  of  the  cooling
medium is not below 293 K (20 °C).

152

"Annex XIII

ANNEX III

PROVISIONS  FOR  ENGINES  PLACED  ON  THE  MARKET  UNDER  A  “FLEXIBLE
SCHEME”

1.

2.

2.1.

2.1.1

2.2.

2.3.

2.4.

2.5.

2.6.

3.

3.1.

3.2.

By the request of an equipment manufacturer (OEM) an engine manufacturer might
during  the  period  between  two  stages  of  limit  values  place  a  limited  number  of
engines  on  the  market  that  only  comply  with  the  previous  stage  of  emission  limit
values in accordance with the following provisions.

An  approval  authority  shall,  on  the  request  by  an  OEM  allow  the  placing  on  the
market of a limited number of engines in each power band that do not comply with
the mandatory emission limit values.

The number of engines exempted shall not exceed 20% of one yearly production of
each power band calculated as the average of the latest 5 years of distribution on the
EU market.

As an option to paragraph 2.1 a manufacturer may instead chooseto exempt a fixed
number of pieces in one or more power bands not exceeding the following: 50 pieces
for 130-560 kW, 100 pieces for 75-130 kW, 150 pieces for 37-75 kW and 200 pieces
for 19-37 kW.

The approval authority shall provide the OEM with a set of labels to be placed on the
equipment  using  the  engines  under  the  flexible  scheme  with  the  following  text:
“Machine  no  …  (sequence  of  machines)  of  …  (total  number  of  machines  in
respective power band) in accordance with approval no ….

The  approval  authority  should  use  the  identifications  in  annex  VIII  to  identify  the
approvals. Example (Austria): 12/2005/1.

The approval authority shall notify all other approval authorities by sending a copy
of the decision to them.

The OEM shall provide the approval authority with all information necessary for the
decision.

The OEM shall cover all costs caused for the approval authority by the procedure of
this flexible scheme.

An  engine  manufacturer  may  place  on  the  market  engines  under  a  flexible  scheme
covered by an approval in accordance with Paragraph 2 of this annex.

The  engine  manufacturer  shall  include  the  information  on  those  engines  and
necessary documentation to the approval authority from which he apply for the type
approval for the engine families concerned.

The engine manufacturer must put a label on those engines with the following text:
“Engine placed on the market under flexible scheme.

153