Regulation No 49 of the Economic Commission for Europe of the United Nations (UN/ECE) — Uniform provisions concerning the measures to be taken against the emission of gaseous and particulate pollutants from compression-ignition engines for use in vehicles, and the emission of gaseous pollutants from positive-ignition engines fuelled with natural gas or liquefied petroleum gas for use in vehicles
Date: 2010-08-31
Institutions: United Nations Economic Commission for Europe
Subjects: UN regional commission, approval, combustion gases, motor vehicle, motor vehicle pollution, natural gas, reduction of gas emissions, technical regulations




L_2010229EN.01000101.xml










31.8.2010   


EN


Official Journal of the European Union


L 229/1






Only the original UN/ECE texts have legal effect under international public law. The status and date of entry into force of this Regulation should be checked in the latest version of the UN/ECE status document TRANS/WP.29/343, available at: http://www.unece.org/trans/main/wp29/wp29wgs/wp29gen/wp29fdocstts.html

Regulation No 49 of the Economic Commission for Europe of the United Nations (UN/ECE) — Uniform provisions concerning the measures to be taken against the emission of gaseous and particulate pollutants from compression-ignition engines for use in vehicles, and the emission of gaseous pollutants from positive-ignition engines fuelled with natural gas or liquefied petroleum gas for use in vehicles

Amendments to Regulation 49 published in OJ L 103, 12.4.2008, p. 1.
Incorporating:
Supplement 1 to the 05 series of amendments — Date of entry into force: 17 March 2010
         
Supplement 2 to the 05 series of amendments — Date of entry into force: 19 August 2010
         
Corrigendum 1 to Supplement 2 — Date of entry into force: 19 August 2010
         
Amendments to the list of contents
The title of Annex 4B, amend to read:


               ‘Test procedure for compression-ignition (CI) engines and positive-ignition (PI) engines fuelled with natural gas (NG) or liquefied petroleum gas (LPG) incorporating the world-wide harmonised heavy-duty certification (WHDC, global technical regulation (gtr) No 4)’
            

The title of Annex 9B, amend to read:


               ‘Technical requirements for on-board diagnostic systems (OBD)’
            

Insert new Annex 9C:







‘Annex 9C —


Technical requirements for assessing the in-use performance of on-board diagnostic systems (OBD)
Appendix 1 — Groups of monitors’
               





Insert new Annex 10


               ‘Annex 10 — Technical requirements on off-cycle emissions (OCE)’
            

Amendments to Annexes
Replace the existing Annex 4B with a new Annex 4B:



‘ANNEX 4B
Test procedure for compression-ignition (CI) engines and positive-ignition (PI) engines fuelled with natural gas (NG) or liquefied petroleum gas (LPG) incorporating the world-wide harmonised heavy duty certification (WHDC, global technical regulation (gtr) No 4)
1.   APPLICABILITY
This annex is not applicable for the purpose of type approval according to this Regulation for the time being. It will be made applicable in the future.
2.   RESERVED. (1)

3.   DEFINITIONS, SYMBOLS AND ABBREVIATIONS
3.1.   Definitions
For the purpose of this Regulation,
3.1.1.   
                              “continuous regeneration” means the regeneration process of an exhaust after-treatment system that occurs either permanently or at least once per WHTC hot start test. Such a regeneration process will not require a special test procedure.
3.1.2.   
                              “delay time” means the difference in time between the change of the component to be measured at the reference point and a system response of 10 per cent of the final reading (t10) with the sampling probe being defined as the reference point. For the gaseous components, this is the transport time of the measured component from the sampling probe to the detector.
3.1.3.   
                              “deNOx system” means an exhaust after-treatment system designed to reduce emissions of oxides of nitrogen (NOx) (e.g. passive and active lean NOx catalysts, NOx adsorbers and selective catalytic reduction (SCR) systems).
3.1.4.   
                              “diesel engine” means an engine which works on the compression-ignition principle.
3.1.5.   
                              “drift” means the difference between the zero or span responses of the measurement instrument after and before an emissions test.
3.1.6.   
                              “engine family” means a manufacturers grouping of engines which, through their design as defined in paragraph 5.2 of this Annex, have similar exhaust emission characteristics; all members of the family shall comply with the applicable emission limit values.
3.1.7.   
                              “engine system” means the engine, the emission control system and the communication interface (hardware and messages) between the engine system electronic control unit(s) (ECU) and any other powertrain or vehicle control unit.
3.1.8.   
                              “engine type” means a category of engines which do not differ in essential engine characteristics.
3.1.9.   
                              “exhaust after-treatment system” means a catalyst (oxidation or 3-way), particulate filter, deNOx system, combined deNOx particulate filter or any other emission-reducing device that is installed downstream of the engine. This definition excludes exhaust gas recirculation (EGR), which is considered an integral part of the engine.
3.1.10.   
                              “full flow dilution method” means the process of mixing the total exhaust flow with diluent prior to separating a fraction of the diluted exhaust stream for analysis.
3.1.11.   
                              “gaseous pollutants” means carbon monoxide, hydrocarbons and/or non-methane hydrocarbons (assuming a ratio of CH1,85 for diesel, CH2,525 for LPG and CH2.93 for NG, and an assumed molecule CH3O0,5 for ethanol fuelled diesel engines), methane (assuming a ratio of CH4 for NG) and oxides of nitrogen (expressed in nitrogen dioxide (NO2) equivalent).
3.1.12.   
                              “high speed (n
hi)” means the highest engine speed where 70 per cent of the declared maximum power occurs.
3.1.13.   
                              “low speed (n
lo)” means the lowest engine speed where 55 per cent of the declared maximum power occurs.
3.1.14.   
                              “maximum power (Pmax)” means the maximum power in kW as specified by the manufacturer.
3.1.15.   
                              “maximum torque speed” means the engine speed at which the maximum torque is obtained from the engine, as specified by the manufacturer.
3.1.16.   
                              “normalised torque” means engine torque in per cent normalised to the maximum available torque at an engine speed.
3.1.17.   
                              “operator demand” means an engine operator's input to control engine output. The operator may be a person (i.e. manual), or a governor (i.e. automatic) that mechanically or electronically signals an input that demands engine output. Input may be from an accelerator pedal or signal, a throttle-control lever or signal, a fuel lever or signal, a speed lever or signal, or a governor setpoint or signal.
3.1.18.   
                              “parent engine” means an engine selected from an engine family in such a way that its emissions characteristics are representative for that engine family.
3.1.19.   
                              “particulate after-treatment device” means an exhaust after-treatment system designed to reduce emissions of particulate pollutants (PM) through a mechanical, aerodynamic, diffusional or inertial separation.
3.1.20.   
                              “partial flow dilution method” means the process of separating a part from the total exhaust flow, then mixing it with an appropriate amount of diluent prior to the particulate sampling filter.
3.1.21.   
                              “particulate matter (PM)” means any material collected on a specified filter medium after diluting exhaust with a clean filtered diluent to a temperature between 315 K (42 °C) and 325 K (52 °C); this is primarily carbon, condensed hydrocarbons, and sulphates with associated water.
3.1.22.   
                              “periodic regeneration” means the regeneration process of an exhaust after-treatment system that occurs periodically in typically less than 100 hours of normal engine operation. During cycles where regeneration occurs, emission standards may be exceeded.
3.1.23.   
                              “ramped steady state test cycle” means a test cycle with a sequence of steady state engine test modes with defined speed and torque criteria at each mode and defined ramps between these modes (WHSC).
3.1.24.   
                              “rated speed” means the maximum full load speed allowed by the governor as specified by the manufacturer in his sales and service literature, or, if such a governor is not present, the speed at which the maximum power is obtained from the engine, as specified by the manufacturer in his sales and service literature.
3.1.25.   
                              “response time” means the difference in time between the change of the component to be measured at the reference point and a system response of 90 per cent of the final reading (t90) with the sampling probe being defined as the reference point, whereby the change of the measured component is at least 60 per cent full scale (FS) and takes place in less than 0,1 second. The system response time consists of the delay time to the system and of the rise time of the system.
3.1.26.   
                              “rise time” means the difference in time between the 10 per cent and 90 per cent response of the final reading (t
90 – t
10).
3.1.27.   
                              “span response” means the mean response to a span gas during a 30 s time interval.
3.1.28.   
                              “specific emissions” means the mass emissions expressed in g/kWh.
3.1.29.   
                              “test cycle” means a sequence of test points each with a defined speed and torque to be followed by the engine under steady state (WHSC) or transient operating conditions (WHTC).
3.1.30.   
                              “transformation time” means the difference in time between the change of the component to be measured at the reference point and a system response of 50 per cent of the final reading (t
50) with the sampling probe being defined as the reference point. The transformation time is used for the signal alignment of different measurement instruments.
3.1.31.   
                              “transient test cycle” means a test cycle with a sequence of normalised speed and torque values that vary relatively quickly with time (WHTC).
3.1.32.   
                              “useful life” means the relevant period of distance and/or time over which compliance with the relevant gaseous and particulate emission limits has to be assured.
3.1.33.   
                              “zero response” means the mean response to a zero gas during a 30 s time interval.




Figure 1


Definitions of system response

Response
step input
response time
transformation time
delay time
rise time
Time
3.2.   General symbols







Symbol


Unit


Term





a
1



—


Slope of the regression





a
0



—


y intercept of the regression





A/F
st



—


Stoichiometric air to fuel ratio





c



ppm/Vol per cent


Concentration





c
d



ppm/Vol per cent


Concentration on dry basis





c
w



ppm/Vol per cent


Concentration on wet basis





c
b



ppm/Vol per cent


Background concentration





C
d



—


Discharge coefficient of SSV





c
gas



ppm/Vol per cent


Concentration on the gaseous components





d



m


Diameter





d
V



m


Throat diameter of venturi





D
0



m3/s


PDP calibration intercept





D



—


Dilution factor





Δt



s


Time interval





e
gas



g/kWh


Specific emission of gaseous components





e
PM



g/kWh


Specific emission of particulates





e
r



g/kWh


Specific emission during regeneration





e
w



g/kWh


Weighted specific emission





E
CO2



per cent


CO2 quench of NOx analyser





E
E



per cent


Ethane efficiency





E
H2O



per cent


Water quench of NOx analyser





E
M



per cent


Methane efficiency





E
NOx



per cent


Efficiency of NOx converter





f



Hz


Data sampling rate





f
a



—


Laboratory atmospheric factor





F
s



—


Stoichiometric factor





H
a



g/kg


Absolute humidity of the intake air





H
d



g/kg


Absolute humidity of the diluent





i



—


Subscript denoting an instantaneous measurement (e.g. 1 Hz)





k
c



—


Carbon specific factor





k
f,d



m3/kg fuel


Combustion additional volume of dry exhaust





k
f,w



m3/kg fuel


Combustion additional volume of wet exhaust





k
h,D



—


Humidity correction factor for NOx for CI engines





k
h,G



—


Humidity correction factor for NOx for PI engines





k
r,u



—


Upward regeneration adjustment factor





k
r,d



—


Downward regeneration adjustment factor





k
w,a



—


Dry to wet correction factor for the intake air





k
w,d



—


Dry to wet correction factor for the diluent





k
w,e



—


Dry to wet correction factor for the diluted exhaust gas





k
w,r



—


Dry to wet correction factor for the raw exhaust gas





K
V



—


CFV calibration function





λ



—


Excess air ratio





m
b



mg


Particulate sample mass of the diluent collected





m
d



kg


Mass of the diluent sample passed through the particulate sampling filters





m
ed



kg


Total diluted exhaust mass over the cycle





m
edf



kg


Mass of equivalent diluted exhaust gas over the test cycle





m
ew



kg


Total exhaust mass over the cycle





m
gas



g


Mass of gaseous emissions over the test cycle





m
f



mg


Particulate sampling filter mass





m
p



mg


Particulate sample mass collected





m
PM



g


Mass of particulate emissions over the test cycle





m
se



kg


Exhaust sample mass over the test cycle





m
sed



kg


Mass of diluted exhaust gas passing the dilution tunnel





m
sep



kg


Mass of diluted exhaust gas passing the particulate collection filters





m
ssd



kg


Mass of secondary diluent





M



Nm


Torque





M
a



g/mol


Molar mass of the intake air





M
d



g/mol


Molar mass of the diluent





M
e



g/mol


Molar mass of the exhaust





M
f



Nm


Torque absorbed by auxiliaries/equipment to be fitted





M
gas



g/mol


Molar mass of gaseous components





M
r



Nm


Torque absorbed by auxiliaries/equipment to be removed




n


—


Number of measurements




nr



—


Number of measurements with regeneration





n



min–1



Engine rotational speed





n
hi



min–1



High engine speed





n
lo



min–1



Low engine speed





n
pref



min–1



Preferred engine speed





n
p



r/s


PDP pump speed





p
a



kPa


Saturation vapour pressure of engine intake air





p
b



kPa


Total atmospheric pressure





p
d



kPa


Saturation vapour pressure of the diluent





P
f



kW


Power absorbed by auxiliaries/equipment to be fitted





p
p



kPa


Absolute pressure





p
r



kW


Water vapour pressure after cooling bath





p
s



kPa


Dry atmospheric pressure





P



kW


Power





P
r



kW


Power absorbed by auxiliaries/equipment to be removed





q

mad



kg/s


Intake air mass flow rate on dry basis





q

maw



kg/s


Intake air mass flow rate on wet basis





q

mCe



kg/s


Carbon mass flow rate in the raw exhaust gas





q

mCf



kg/s


Carbon mass flow rate into the engine





q

mCp



kg/s


Carbon mass flow rate in the partial flow dilution system





q

mdew



kg/s


Diluted exhaust gas mass flow rate on wet basis





q

mdw



kg/s


Diluent mass flow rate on wet basis





q

medf



kg/s


Equivalent diluted exhaust gas mass flow rate on wet basis





q

mew



kg/s


Exhaust gas mass flow rate on wet basis





q

mex



kg/s


Sample mass flow rate extracted from dilution tunnel





q

mf



kg/s


Fuel mass flow rate





q

mp



kg/s


Sample flow of exhaust gas into partial flow dilution system





q

vCVS



m3/s


CVS volume rate





q

vs



dm3/min


System flow rate of exhaust analyser system





q

vt



cm3/min


Tracer gas flow rate





r2




—


Coefficient of determination





r
d



—


Dilution ratio





r
D



—


Diameter ratio of SSV





r
h



—


Hydrocarbon response factor of the FID





r
m



—


Methanol response factor of the FID





r
p



—


Pressure ratio of SSV





r
s



—


Average sample ratio





ρ



kg/m3



Density





ρ
e



kg/m3



Exhaust gas density





σ



—


Standard deviation





s



 


Standard deviation





T



K


Absolute temperature





T
a



K


Absolute temperature of the intake air





t



s


Time





t
10



s


Time between step input and 10 per cent of final reading





t
50



s


Time between step input and 50 per cent of final reading





t
90



s


Time between step input and 90 per cent of final reading





u



—


Ratio between the densities (or molar masses) of the gas components and the exhaust gas divided by 1 000 





V
0



m3/r


PDP gas volume pumped per revolution





V
s



dm3



System volume of exhaust analyser bench





W
act



kWh


Actual cycle work of the test cycle





W
ref



kWh


Reference cycle work of the test cycle





X
0



m3/r


PDP calibration function




3.3.   Symbols and abbreviations for the fuel composition







w
ALF



hydrogen content of fuel, per cent mass





w
BET



carbon content of fuel, per cent mass





w
GAM



sulphur content of fuel, per cent mass





w
DEL



nitrogen content of fuel, per cent mass





w
EPS



oxygen content of fuel, per cent mass





α



molar hydrogen ratio (H/C)





γ



molar sulphur ratio (S/C)





δ



molar nitrogen ratio (N/C)





ε



molar oxygen ratio (O/C)




referring to a fuel CH
α
O
ε
N
δ
S
γ


3.4.   Symbols and abbreviations for the chemical components






C1


Carbon 1 equivalent hydrocarbon




CH4



Methane




C2H6



Ethane




C3H8



Propane




CO


Carbon monoxide




CO2



Carbon dioxide




DOP


Di-octylphtalate




HC


Hydrocarbons




H2O


Water




NMHC


Non-methane hydrocarbons




NOx



Oxides of nitrogen




NO


Nitric oxide




NO2



Nitrogen dioxide




PM


Particulate matter




3.5.   Abbreviations






CFV


Critical Flow Venturi




CLD


Chemiluminescent Detector




CVS


Constant Volume Sampling




deNOx



NOx after-treatment system




EGR


Exhaust gas recirculation




FID


Flame Ionisation Detector




GC


Gas Chromatograph




HCLD


Heated Chemiluminescent Detector




HFID


Heated Flame Ionisation Detector




LPG


Liquefied Petroleum Gas




NDIR


Non-Dispersive Infrared (Analyser)




NG


Natural Gas




NMC


Non-Methane Cutter




PDP


Positive Displacement Pump




Per cent FS


Per cent of full scale




PFS


Partial Flow System




SSV


Subsonic Venturi




VGT


Variable Geometry Turbine




4.   GENERAL REQUIREMENTS
The engine system shall be so designed, constructed and assembled as to enable the engine in normal use to comply with the provisions of this Annex during its useful life, as defined in this Regulation, including when installed in the vehicle.
5.   PERFORMANCE REQUIREMENTS
5.1.   Emission of gaseous and particulate pollutants
The emissions of gaseous and particulate pollutants by the engine shall be determined on the WHTC and WHSC test cycles, as described in paragraph 7. The measurement systems shall meet the linearity requirements in paragraph 9.2 and the specifications in paragraph 9.3 (gaseous emissions measurement), paragraph 9.4 (particulate measurement) and in Appendix 3.
Other systems or analysers may be approved by the type approval authority, if it is found that they yield equivalent results in accordance with paragraph 5.1.1.
5.1.1.   Equivalency
The determination of system equivalency shall be based on a seven-sample pair (or larger) correlation study between the system under consideration and one of the systems of this Annex.

                              “Results” refer to the specific cycle weighted emissions value. The correlation testing is to be performed at the same laboratory, test cell, and on the same engine, and is preferred to be run concurrently. The equivalency of the sample pair averages shall be determined by F-test and t-test statistics as described in Appendix 4, paragraph A.4.3, obtained under the laboratory test cell and the engine conditions described above. Outliers shall be determined in accordance with ISO 5725 and excluded from the database. The systems to be used for correlation testing shall be subject to the approval by the type approval authority.
5.2.   Engine family
5.2.1.   General
An engine family is characterised by design parameters. These shall be common to all engines within the family. The engine manufacturer may decide which engines belong to an engine family, as long as the membership criteria listed in paragraph 5.2.3 are respected. The engine family shall be approved by the type approval authority. The manufacturer shall provide to the type approval authority the appropriate information relating to the emission levels of the members of the engine family.
5.2.2.   Special cases
In some cases there may be interaction between parameters. This shall be taken into consideration to ensure that only engines with similar exhaust emission characteristics are included within the same engine family. These cases shall be identified by the manufacturer and notified to the type approval authority. It shall then be taken into account as a criterion for creating a new engine family.
In case of devices or features, which are not listed in paragraph 5.2.3 and which have a strong influence on the level of emissions, this equipment shall be identified by the manufacturer on the basis of good engineering practice, and shall be notified to the type approval authority. It shall then be taken into account as a criterion for creating a new engine family.
In addition to the parameters listed in paragraph 5.2.3, the manufacturer may introduce additional criteria allowing the definition of families of more restricted size. These parameters are not necessarily parameters that have an influence on the level of emissions.
5.2.3.   Parameters defining the engine family
5.2.3.1.   Combustion cycle






(a)


2-stroke cycle










(b)


4-stroke cycle










(c)


Rotary engine










(d)


Others




5.2.3.2.   Configuration of the cylinders
5.2.3.2.1.   Position of the cylinders in the block






(a)


V










(b)


In line










(c)


Radial










(d)


Others (F, W, etc.)




5.2.3.2.2.   Relative position of the cylinders
Engines with the same block may belong to the same family as long as their bore centre-to-centre dimensions are the same.
5.2.3.3.   Main cooling medium






(a)


air










(b)


water










(c)


oil




5.2.3.4.   Individual cylinder displacement
5.2.3.4.1.   Engine with a unit cylinder displacement ≥ 0,75 dm3

In order for engines with a unit cylinder displacement of ≥ 0,75 dm3 to be considered to belong to the same engine family, the spread of their individual cylinder displacements shall not exceed 15 per cent of the largest individual cylinder displacement within the family.
5.2.3.4.2.   Engine with a unit cylinder displacement < 0,75 dm3

In order for engines with a unit cylinder displacement of < 0,75 dm3 to be considered to belong to the same engine family, the spread of their individual cylinder displacements shall not exceed 30 per cent of the largest individual cylinder displacement within the family.
5.2.3.4.3.   Engine with other unit cylinder displacement limits
Engines with an individual cylinder displacement that exceeds the limits defined in paragraphs 5.2.3.4.1 and 5.2.3.4.2 may be considered to belong to the same family with the approval of the type approval authority. The approval shall be based on technical elements (calculations, simulations, experimental results etc.) showing that exceeding the limits does not have a significant influence on the exhaust emissions.
5.2.3.5.   Method of air aspiration






(a)


Naturally aspirated










(b)


Pressure charged










(c)


Pressure charged with charge cooler




5.2.3.6.   Fuel type






(a)


Diesel










(b)


Natural gas (NG)










(c)


Liquefied petroleum gas (LPG)










(d)


Ethanol




5.2.3.7.   Combustion chamber type






(a)


Open chamber










(b)


Divided chamber










(c)


Other types




5.2.3.8.   Ignition Type






(a)


Positive ignition










(b)


Compression ignition




5.2.3.9.   Valves and porting






(a)


Configuration










(b)


Number of valves per cylinder




5.2.3.10.   Fuel supply type






(a)


Liquid fuel supply type






(i)


Pump and (high pressure) line and injector










(ii)


In-line or distributor pump










(iii)


Unit pump or unit injector










(iv)


Common rail










(v)


Carburettor(s)










(vi)


Others














(b)


Gas fuel supply type






(i)


Gaseous










(ii)


Liquid










(iii)


Mixing units










(iv)


Others














(c)


Other types




5.2.3.11.   Miscellaneous devices






(a)


Exhaust gas recirculation (EGR)










(b)


Water injection










(c)


Air injection










(d)


Others




5.2.3.12.   Electronic control strategy
The presence or absence of an electronic control unit (ECU) on the engine is regarded as a basic parameter of the family.
In the case of electronically controlled engines, the manufacturer shall present the technical elements explaining the grouping of these engines in the same family, i.e. the reasons why these engines can be expected to satisfy the same emission requirements.
These elements can be calculations, simulations, estimations, description of injection parameters, experimental results, etc.
Examples of controlled features are:






(a)


Timing










(b)


Injection pressure










(c)


Multiple injections










(d)


Boost pressure










(e)


VGT










(f)


EGR




5.2.3.13.   Exhaust after-treatment systems
The function and combination of the following devices are regarded as membership criteria for an engine family:






(a)


Oxidation catalyst










(b)


Three-way catalyst










(c)


DeNOx system with selective reduction of NOx (addition of reducing agent)










(d)


Other DeNOx systems










(e)


Particulate trap with passive regeneration










(f)


Particulate trap with active regeneration










(g)


Other particulate traps










(h)


Other devices




When an engine has been certified without after-treatment system, whether as parent engine or as member of the family, then this engine, when equipped with an oxidation catalyst, may be included in the same engine family, if it does not require different fuel characteristics.
If it requires specific fuel characteristics (e.g. particulate traps requiring special additives in the fuel to ensure the regeneration process), the decision to include it in the same family shall be based on technical elements provided by the manufacturer. These elements shall indicate that the expected emission level of the equipped engine complies with the same limit value as the non-equipped engine.
When an engine has been certified with after-treatment system, whether as parent engine or as member of a family, whose parent engine is equipped with the same after-treatment system, then this engine, when equipped without after-treatment system, shall not be added to the same engine family.
5.2.4.   Choice of the parent engine
5.2.4.1.   Compression ignition engines
Once the engine family has been agreed by the type approval authority, the parent engine of the family shall be selected using the primary criterion of the highest fuel delivery per stroke at the declared maximum torque speed. In the event that two or more engines share this primary criterion, the parent engine shall be selected using the secondary criterion of highest fuel delivery per stroke at rated speed.
5.2.4.2.   Positive ignition engines
Once the engine family has been agreed by the type approval authority, the parent engine of the family shall be selected using the primary criterion of the largest displacement. In the event that two or more engines share this primary criterion, the parent engine shall be selected using the secondary criterion in the following order of priority:






(a)


the highest fuel delivery per stroke at the speed of declared rated power;










(b)


the most advanced spark timing;










(c)


the lowest EGR rate.




5.2.4.3.   Remarks on the choice of the parent engine
The type approval authority may conclude that the worst-case emission of the family can best be characterised by testing additional engines. In this case, the engine manufacturer shall submit the appropriate information to determine the engines within the family likely to have the highest emissions level.
If engines within the family incorporate other features which may be considered to affect exhaust emissions, these features shall also be identified and taken into account in the selection of the parent engine.
If engines within the family meet the same emission values over different useful life periods, this shall be taken into account in the selection of the parent engine.
6.   TEST CONDITIONS
6.1.   Laboratory test conditions
The absolute temperature (T
a) of the engine intake air expressed in Kelvin, and the dry atmospheric pressure (p
s), expressed in kPa shall be measured and the parameter f
a shall be determined according to the following provisions. In multi-cylinder engines having distinct groups of intake manifolds, such as in a “Vee” engine configuration, the average temperature of the distinct groups shall be taken. The parameter f
a shall be reported with the test results. For better repeatability and reproducibility of the test results, it is recommended that the parameter f
a be such that: 0,93 ≤ f
a ≤ 1,07.






(a)


Compression-ignition engines:
Naturally aspirated and mechanically supercharged engines:



 (1)
Turbocharged engines with or without cooling of the intake air:



 (2)










(b)


Positive ignition engines:



 (3)




6.2.   Engines with charge air-cooling
The charge air temperature shall be recorded and shall be, at the rated speed and full load, within ± 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).
If a test laboratory system or external blower is used, the coolant flow rate shall be set to achieve a charge air temperature within ± 5 K of the maximum charge air temperature specified by the manufacturer at the rated speed 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, unless this results in unrepresentative overcooling of the charge air. The charge air cooler volume shall be based upon good engineering practice and shall be representative of the production engine's in-use installation. The laboratory system shall be designed to minimise accumulation of condensate. Any accumulated condensate shall be drained and all drains shall be completely closed before emission testing.
If the engine manufacturer specifies pressure-drop limits across the charge-air cooling system, it shall be ensured that the pressure drop across the charge-air cooling system at engine conditions specified by the manufacturer is within the manufacturer's specified limit(s). The pressure drop shall be measured at the manufacturer's specified locations.
6.3.   Engine power
The basis of specific emissions measurement is engine power and cycle work as determined in accordance with paragraphs 6.3.1 to 6.3.5.
6.3.1.   General engine installation
The engine shall be tested with the auxiliaries/equipment listed in Appendix 7.
If auxiliaries/equipment are not installed as required, their power shall be taken into account in accordance with paragraphs 6.3.2 to 6.3.5.
6.3.2.   Auxiliaries/equipment to be fitted for the emissions test
If it is inappropriate to install the auxiliaries/equipment required according to Appendix 7 on the test bench, the power absorbed by them shall be determined and subtracted from the measured engine power (reference and actual) over the whole engine speed range of the WHTC and over the test speeds of the WHSC.
6.3.3.   Auxiliaries/equipment to be removed for the test
Where the auxiliaries/equipment not required according to Appendix 7 cannot be removed, the power absorbed by them may be determined and added to the measured engine power (reference and actual) over the whole engine speed range of the WHTC and over the test speeds of the WHSC. If this value is greater than 3 per cent of the maximum power at the test speed it shall be demonstrated to the type approval authority.
6.3.4.   Determination of auxiliary power
The power absorbed by the auxiliaries/equipment needs only be determined, if






(a)


auxiliaries/equipment required according to Appendix 7, are not fitted to the engine
and/or










(b)


auxiliaries/equipment not required according to Appendix 7, are fitted to the engine.




The values of auxiliary power and the measurement/calculation method for determining auxiliary power shall be submitted by the engine manufacturer for the whole operating area of the test cycles, and approved by the type approval authority.
6.3.5.   Engine cycle work
The calculation of reference and actual cycle work (see paragraphs 7.4.8 and 7.8.6) shall be based upon engine power according to paragraph 6.3.1. In this case, P
f and P
r of equation 4 are zero, and P equals P
m.
If auxiliaries/equipment are installed according to paragraphs 6.3.2 and/or 6.3.3, the power absorbed by them shall be used to correct each instantaneous cycle power value P
m,i, as follows:



 (4)
where:







P
m,i



is the measured engine power, kW





P
f,i



is the power absorbed by auxiliaries/equipment to be fitted, kW





P
r,i



is the power absorbed by auxiliaries/equipment to be removed, kW




6.4.   Engine air intake system
An engine air intake system or a test laboratory system shall be used presenting an air intake restriction within ± 300 Pa of the maximum value specified by the manufacturer for a clean air cleaner at the rated speed and full load. The static differential pressure of the restriction shall be measured at the location specified by the manufacturer.
6.5.   Engine exhaust system
An engine exhaust system or a test laboratory system shall be used presenting an exhaust backpressure within 80 to 100 per cent of the maximum value specified by the manufacturer at the rated speed and full load. If the maximum restriction is 5 kPa or less, the set point shall be no less than 1,0 kPa from the maximum. The exhaust system shall conform to the requirements for exhaust gas sampling, as set out in paragraphs 9.3.10 and 9.3.11.
6.6.   Engine with exhaust after-treatment system
If the engine is equipped with an exhaust after-treatment system, the exhaust pipe shall have the same diameter as found in-use, or as specified by the manufacturer, for at least four pipe diameters upstream of the expansion section containing the after-treatment device. The distance from the exhaust manifold flange or turbocharger outlet to the exhaust after-treatment system 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. For variable-restriction after-treatment devices, the maximum exhaust restriction is defined at the after-treatment condition (de-greening/aging and regeneration/loading level) specified by the manufacturer. If the maximum restriction is 5 kPa or less, the set point shall be no less than 1,0 kPa from the maximum. The after-treatment container may be removed during dummy tests and during engine mapping, and replaced with an equivalent container having an inactive catalyst support.
The emissions measured on the test cycle shall be representative of the emissions in the field. In the case of an engine equipped with a exhaust after-treatment system that requires the consumption of a reagent, the reagent used for all tests shall be declared by the manufacturer.
Engines equipped with exhaust after-treatment systems with continuous regeneration do not require a special test procedure, but the regeneration process needs to be demonstrated according to paragraph 6.6.1.
For engines equipped with exhaust after-treatment systems that are regenerated on a periodic basis, as described in paragraph 6.6.2, emission results shall be adjusted to account for regeneration events. In this case, the average emission depends on the frequency of the regeneration event in terms of fraction of tests during which the regeneration occurs.
6.6.1.   Continuous regeneration
The emissions shall be measured on an after-treatment system that has been stabilised so as to result in repeatable emissions behaviour. The regeneration process shall occur at least once during the WHTC hot start test and the manufacturer shall declare the normal conditions under which regeneration occurs (soot load, temperature, exhaust back-pressure, etc.).
In order to demonstrate that the regeneration process is continuous, at least three WHTC hot start tests shall be conducted. For the purpose of this demonstration, the engine shall be warmed up in accordance with paragraph 7.4.1, the engine be soaked according to paragraph 7.6.3 and the first WHTC hot start test be run. The subsequent hot start tests shall be started after soaking according to paragraph 7.6.3. During the tests, exhaust temperatures and pressures shall be recorded (temperature before and after the after-treatment system, exhaust back pressure, etc.).
If the conditions declared by the manufacturer occur during the tests and the results of the three (or more) WHTC hot start tests do not scatter by more than ± 25 per cent or 0,005 g/kWh, whichever is greater, the after-treatment system is considered to be of the continuous regeneration type, and the general test provisions of paragraph 7.6 (WHTC) and paragraph 7.7 (WHSC) apply.
If the exhaust after-treatment system has a security mode that shifts to a periodic regeneration mode, it shall be checked according to paragraph 6.6.2. For that specific case, the applicable emission limits may be exceeded and would not be weighted.
6.6.2.   Periodic regeneration
For an exhaust after-treatment based on a periodic regeneration process, the emissions shall be measured on at least three WHTC hot start tests, one with and two without a regeneration event on a stabilised after-treatment system, and the results be weighted in accordance with equation 5.
The regeneration process shall occur at least once during the WHTC hot start test. The engine may be equipped with a switch capable of preventing or permitting the regeneration process provided this operation has no effect on the original engine calibration.
The manufacturer shall declare the normal parameter conditions under which the regeneration process occurs (soot load, temperature, exhaust back-pressure, etc.) and its duration. The manufacturer shall also provide the frequency of the regeneration event in terms of number of tests during which the regeneration occurs compared to number of tests without regeneration. The exact procedure to determine this frequency shall be based upon in use data using good engineering judgement, and shall be agreed by the type approval or certification authority.
The manufacturer shall provide an after-treatment system that has been loaded in order to achieve regeneration during a WHTC test. For the purpose of this testing, the engine shall be warmed up in accordance with paragraph 7.4.1, the engine be soaked according to paragraph 7.6.3 and the WHTC hot start test be started. Regeneration shall not occur during the engine warm-up.
Average specific emissions between regeneration phases shall be determined from the arithmetic mean of several approximately equidistant WHTC hot start test results (g/kWh). As a minimum, at least one WHTC hot start test as close as possible prior to a regeneration test and one WHTC hot start test immediately after a regeneration test shall be conducted. As an alternative, the manufacturer may provide data to show that the emissions remain constant (±25 per cent or 0,005 g/kWh, whichever is greater) between regeneration phases. In this case, the emissions of only one WHTC hot start test may be used.
During the regeneration test, all the data needed to detect regeneration shall be recorded (CO or NOx emissions, temperature before and after the after-treatment system, exhaust back pressure, etc.).
During the regeneration test, the applicable emission limits may be exceeded.
The test procedure is schematically shown in figure 2.




Figure 2


Scheme of periodic regeneration

Emissions (g/KwH)
Emissions during regeneration er
Mean emissions during sampling e1…n
Weighted emissions of sampling and regeneration ew
Number of cycles
The WHTC hot start emissions shall be weighted as follows:



 (5)
where:






n


is the number of WHTC hot start tests without regeneration




nr



is the number of WHTC hot start tests with regeneration (minimum one test)











is the average specific emission without regeneration, g/kWh











is the average specific emission with regeneration, g/kWh




For the determination of 

, the following provisions apply:






(a)


If regeneration takes more than one hot start WHTC, consecutive full hot start WHTC tests shall be conducted and emissions continued to be measured without soaking and without shutting the engine off, until regeneration is completed, and the average of the hot start WHTC tests be calculated.










(b)


If regeneration is completed during any hot start WHTC, the test shall be continued over its entire length.




In agreement with the type approval authority, the regeneration adjustment factors may be applied either multiplicative (c) or additive (d) based upon good engineering analysis.






(c)


The multiplicative adjustment factors shall be calculated as follows:



 (upward) (6)



 (downward) (6a)










(d)


The additive adjustment factors shall be calculated as follows:



 (upward) (7)



 (downward) (8)




With reference to the specific emission calculations in paragraph 8.6.3, the regeneration adjustment factors shall be applied, as follows:






(e)


for a test without regeneration, k
r,u shall be multiplied with or be added to, respectively, the specific emission e in equations 69 or 70,










(f)


for a test with regeneration, k
r,d shall be multiplied with or be subtracted from, respectively, the specific emission e in equations 69 or 70.




At the request of the manufacturer, the regeneration adjustment factors






(g)


may be extended to other members of the same engine family,










(h)


may be extended to other engine families using the same after-treatment system with the prior approval of the type approval or certification authority based on technical evidence to be supplied by the manufacturer, that the emissions are similar.




6.7.   Cooling system
An engine cooling system with sufficient capacity to maintain the engine at normal operating temperatures prescribed by the manufacturer shall be used.
6.8.   Lubricating oil
The lubricating oil shall be specified by the manufacturer and be representative of lubricating oil available on the market; the specifications of the lubricating oil used for the test shall be recorded and presented with the results of the test.
6.9.   Specification of the reference fuel
The reference fuel is specified in Appendix 2 of this Annex for CI engines and in Annexes 6 and 7 for CNG and LPG fuelled engines.
The fuel temperature shall be in accordance with the manufacturer’s recommendations.
6.10.   Crankcase emissions
No crankcase emissions shall be discharged directly into the ambient atmosphere, with the following exception: engines equipped with turbochargers, pumps, blowers, or superchargers for air induction may discharge crankcase emissions to the ambient atmosphere if the emissions are added to the exhaust emissions (either physically or mathematically) during all emission testing. Manufacturers taking advantage of this exception shall install the engines so that all crankcase emission can be routed into the emissions sampling system.
For the purpose of this paragraph, crankcase emissions that are routed into the exhaust upstream of exhaust after-treatment during all operation are not considered to be discharged directly into the ambient atmosphere.
Open crankcase emissions shall be routed into the exhaust system for emission measurement, as follows:






(a)


The tubing materials shall be smooth-walled, electrically conductive, and not reactive with crankcase emissions. Tube lengths shall be minimised as far as possible.










(b)


The number of bends in the laboratory crankcase tubing shall be minimised, and the radius of any unavoidable bend shall be maximised.










(c)


The laboratory crankcase exhaust tubing shall be heated, thin-walled or insulated and shall meet the engine manufacturer’s specifications for crankcase back pressure.










(d)


The crankcase exhaust tubing shall connect into the raw exhaust downstream of any after-treatment system, downstream of any installed exhaust restriction, and sufficiently upstream of any sample probes to ensure complete mixing with the engine’s exhaust before sampling. The crankcase exhaust tube shall extend into the free stream of exhaust to avoid boundary-layer effects and to promote mixing. The crankcase exhaust tube’s outlet may orient in any direction relative to the raw exhaust flow.




7.   TEST PROCEDURES
7.1.   Principles of emissions measurement
To measure the specific emissions, the engine shall be operated over the test cycles defined in paragraphs 7.2.1 and 7.2.2. The measurement of specific emissions requires the determination of the mass of components in the exhaust and the corresponding engine cycle work. The components are determined by the sampling methods described in paragraphs 7.1.1 and 7.1.2.
7.1.1.   Continuous sampling
In continuous sampling, the component’s concentration is measured continuously from raw or dilute exhaust. This concentration is multiplied by the continuous (raw or dilute) exhaust flow rate at the emission sampling location to determine the component’s mass flow rate. The component’s emission is continuously summed over the test cycle. This sum is the total mass of the emitted component.
7.1.2.   Batch sampling
In batch sampling, a sample of raw or dilute exhaust is continuously extracted and stored for later measurement. The extracted sample shall be proportional to the raw or dilute exhaust flow rate. Examples of batch sampling are collecting diluted gaseous components in a bag and collecting particulate matter (PM) on a filter. The batch sampled concentrations are multiplied by the total exhaust mass or mass flow (raw or dilute) from which it was extracted during the test cycle. This product is the total mass or mass flow of the emitted component. To calculate the PM concentration, the PM deposited onto a filter from proportionally extracted exhaust shall be divided by the amount of filtered exhaust.
7.1.3.   Measurement procedures
This annex applies two measurement procedures that are functionally equivalent. Both procedures may be used for both the WHTC and the WHSC test cycle:






(a)


the gaseous components are sampled continuously in the raw exhaust gas, and the particulates are determined using a partial flow dilution system;










(b)


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




Any combination of the two principles (e.g. raw gaseous measurement and full flow particulate measurement) is permitted.
7.2.   Test cycles
7.2.1.   Transient test cycle WHTC
The transient test cycle WHTC is listed in Appendix 1 as a second-by-second sequence of normalised speed and torque values. 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 the engine-mapping curve. The conversion is referred to as denormalisation, and the test cycle so developed as the reference cycle of the engine to be tested. With those reference speed and torque values, the cycle shall be run on the test cell, and the actual speed, torque and power values shall be recorded. In order to validate the test run, a regression analysis between reference and actual speed, torque and power values shall be conducted upon completion of the test.
For calculation of the brake specific emissions, the actual cycle work shall be calculated by integrating actual engine power over the cycle. For cycle validation, the actual cycle work shall be within prescribed limits of the reference cycle work.
For the gaseous pollutants, continuous sampling (raw or dilute exhaust gas) or batch sampling (dilute exhaust gas) may be used. The particulate sample shall be diluted with a conditioned diluent (such as ambient air), and collected on a single suitable filter. The WHTC is shown schematically in figure 3.




Figure 3


WHTC test cycle

Normalized Speed/Torque
n_norm
M_norm
Time(s)
7.2.2.   Ramped steady state test cycle WHSC
The ramped steady state test cycle WHSC consists of a number of normalised speed and load modes which shall be converted to the reference values for the individual engine under test based on the engine-mapping curve. The engine shall be operated for the prescribed time in each mode, whereby engine speed and load shall be changed linearly within 20 ± 1 seconds. In order to validate the test run, a regression analysis between reference and actual speed, torque and power values shall be conducted upon completion of the test.
The concentration of each gaseous pollutant, exhaust flow and power output shall be determined over the test cycle. The gaseous pollutants may be recorded continuously or sampled into a sampling bag. The particulate sample shall be diluted with a conditioned diluent (such as ambient air). One sample over the complete test procedure shall be taken, and collected on a single suitable filter.
For calculation of the brake specific emissions, the actual cycle work shall be calculated by integrating actual engine power over the cycle.
The WHSC is shown in table 1. Except for mode 1, the start of each mode is defined as the beginning of the ramp from the previous mode.
Table 1
WHSC test cycle








Mode


Normalised speed
(per cent)


Normalised torque
(per cent)


Mode length(s)
incl. 20 s ramp




1


0


0


210




2


55


100


50




3


55


25


250




4


55


70


75




5


35


100


50




6


25


25


200




7


45


70


75




8


45


25


150




9


55


50


125




10


75


100


50




11


35


50


200




12


35


25


250




13


0


0


210




Sum


1 895 




7.3.   General test sequence
The following flow chart outlines the general guidance that should be followed during testing. The details of each step are described in the relevant paragraphs. Deviations from the guidance are permitted where appropriate, but the specific requirements of the relevant paragraphs are mandatory.
For the WHTC, the test procedure consists of a cold start test following either natural or forced cool-down of the engine, a hot soak period and a hot start test.
For the WHSC, the test procedure consists of a hot start test following engine preconditioning at WHSC mode 9.



Engine preparation, pre-test measurements, performance checks and calibrations
Generate engine map (maximum torque curve)
paragraph 7.4.3
Generate reference test cycle
paragraph 7.4.6
Run one or more practice cycles as necessary to check engine/test cell/emissions systems
WHTC
Natural or forced engine cool-down
paragraph 7.6.1
WHSC
Ready all systems for sampling and data collection
paragraph 7.5.2
Preconditioning of engine and particulate system including dilution tunnel
paragraph 7.7.1
Cold start exhaust emissions test
paragraph 7.6.2
Change dummy PM filter to weighed sampling filter in system by-pass mode
paragraph 7.7.1
Ready all systems for sampling and data collection
paragraph 7.5.2
Hot soak period
paragraph 7.6.3
Hot start exhaust emissions test
paragraph 7.6.4
Exhaust emissions test within 5 minutes after engine shut down
paragraph 7.7.3
Test cycle validation
paragraph 7.8.6.7
Data collection and evaluation
paragraph 7.7.4
Emissions calculation
paragraph 8
7.4.   Engine mapping and reference cycle
Pre-test engine measurements, pre-test engine performance checks and pre-test system calibrations shall be made prior to the engine mapping procedure in line with the general test sequence shown in paragraph 7.3.
As basis for WHTC and WHSC reference cycle generation, the engine shall be mapped under full load operation for determining the speed vs. maximum torque and speed vs. maximum power curves. The mapping curve shall be used for denormalising engine speed (paragraph 7.4.6) and engine torque (paragraph 7.4.7).
7.4.1.   Engine warm-up
The engine shall be warmed up between 75 per cent and 100 per cent of its maximum power or according to the recommendation of the manufacturer and good engineering judgment. Towards the end of the warm up it shall be operated in order to stabilise the engine coolant and lube oil temperatures to within ± 2 per cent of its mean values for at least 2 minutes or until the engine thermostat controls engine temperature.
7.4.2.   Determination of the mapping speed range
The minimum and maximum mapping speeds are defined as follows:







Minimum mapping speed


=


idle speed




Maximum mapping speed


=



n
hi × 1,02 or speed where full load torque drops off to zero, whichever is smaller.




7.4.3.   Engine mapping curve
When the engine is stabilised according to paragraph 7.4.1, the engine mapping shall be performed according to the following procedure.






(a)


The engine shall be unloaded and operated at idle speed.










(b)


The engine shall be operated with maximum operator demand at minimum mapping speed.










(c)


The engine speed shall be increased at an average rate of 8 ± 1 min–1/s from minimum to maximum mapping speed, or at a constant rate such that it takes 4 to 6 min to sweep 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.




When selecting option (b) in paragraph 7.4.7 for determining negative reference torque, the mapping curve may directly continue with minimum operator demand from maximum to minimum mapping speed.
7.4.4.   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 shall 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 paragraph for reasons of safety or representativeness shall be approved by the type approval authority along with the justification for their use. In no case, however, the torque curve shall be run by descending engine speeds for governed or turbocharged engines.
7.4.5.   Replicate tests
An engine need not be mapped before each and every test cycle. An engine shall be remapped prior to a test cycle if:






(a)


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










(b)


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




7.4.6.   Denormalisation of engine speed
For generating the reference cycles, the normalised speeds of Appendix 1 (WHTC) and table 1 (WHSC) shall be denormalised using the following equation:



 (9)
For determination of n
pref, the integral of the maximum torque shall be calculated from n
idle to n
95h from the engine mapping curve, as determined in accordance with paragraph 7.4.3.
The engine speeds in figures 4 and 5 are defined, as follows:







n
lo



is the lowest speed where the power is 55 per cent of maximum power





n
pref



is the engine speed where the integral of max. mapped torque is 51 per cent of the whole integral between n
idle and n
95h






n
hi



is the highest speed where the power is 70 per cent of maximum power





n
idle



is the idle speed





n
95h



is the highest speed where the power is 95 per cent of maximum power




For engines (mainly positive ignition engines) with a steep governor droop curve, where fuel cut off does not permit to operate the engine up to n
hi or n
95h, the following provisions apply:







n
hi



in equation 9 is replaced with n
Pmax × 1,02





n
95h



is replaced with n
Pmax × 1,02








Figure 4


Definition of test speeds

Engine Power
Pmax
95 % of Pmax
70 % of Pmax
55 % of Pmax
Engine Speed




Figure 5


Definition of n
pref


Engine Torque
Area = 51 %
Area = 100 %
Engine Speed
7.4.7.   Denormalisation of engine torque
The torque values in the engine dynamometer schedule of Appendix 1 (WHTC) and in table 1 (WHSC) are normalised to the maximum torque at the respective speed. For generating the reference cycles, the torque values for each individual reference speed value as determined in paragraph 7.4.6 shall be denormalised, using the mapping curve determined according to paragraph 7.4.3, as follows:



 (10)
where:







M
norm,i



is the normalised torque, per cent





M
max,i



is the maximum torque from the mapping curve, Nm





M
f,i



is the torque absorbed by auxiliaries/equipment to be fitted, Nm





M
r,i



is the torque absorbed by auxiliaries/equipment to be removed, Nm




If auxiliaries/equipment are fitted in accordance with paragraph 6.3.1 and Appendix 7, M
f and M
r are zero.
The negative torque values of the motoring points (m in Appendix 1) shall take on, for purposes of reference cycle generation, reference values determined in either of the following ways:






(a)


negative 40 per cent of the positive torque available at the associated speed point;










(b)


mapping of the negative torque required to motor the engine from maximum to minimum mapping speed;










(c)


determination of the negative torque required to motor the engine at idle and at n
hi and linear interpolation between these two points.




7.4.8.   Calculation of reference cycle work
Reference cycle work shall be determined over the test cycle by synchronously calculating instantaneous values for engine power from reference speed and reference torque, as determined in paragraphs 7.4.6 and 7.4.7. Instantaneous engine power values shall be integrated over the test cycle to calculate the reference cycle work W
ref (kWh). If auxiliaries are not fitted in accordance with paragraph 6.3.1, the instantaneous power values shall be corrected using equation (4) in paragraph 6.3.5.
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. In integrating the actual cycle work, any negative torque values shall be set equal to zero and included. If integration is performed at a frequency of less than 5 Hz, 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.
7.5.   Pre-test procedures
7.5.1.   Installation of the measurement equipment
The instrumentation and sample probes shall be installed as required. The tailpipe shall be connected to the full flow dilution system, if used.
7.5.2.   Preparation of measurement equipment for sampling
The following steps shall be taken before emission sampling begins:






(a)


Leak checks shall be performed within 8 hours prior to emission sampling according to paragraph 9.3.4.










(b)


For batch sampling, clean storage media shall be connected, such as evacuated bags.










(c)


All measurement instruments shall be started according to the instrument manufacturer’s instructions and good engineering judgment.










(d)


Dilution systems, sample pumps, cooling fans, and the data-collection system shall be started.










(e)


The sample flow rates shall be adjusted to desired levels, using bypass flow, if desired.










(f)


Heat exchangers in the sampling system shall be pre-heated or pre-cooled to within their operating temperature ranges for a test.










(g)


Heated or cooled components such as sample lines, filters, coolers, and pumps shall be allowed to stabilise at their operating temperatures.










(h)


Exhaust dilution system flow shall be switched on at least 10 minutes before a test sequence.










(i)


Any electronic integrating devices shall be zeroed or re-zeroed, before the start of any test interval.




7.5.3.   Checking the gas analysers
Gas analyser ranges shall be selected. Emission analysers with automatic or manual range switching are permitted. During the test cycle, the range of the emission analysers shall not be switched. At the same time the gains of an analyser’s analogue operational amplifier(s) may not be switched during the test cycle.
Zero and span response shall be determined for all analysers using internationally-traceable gases that meet the specifications of paragraph 9.3.3. FID analysers shall be spanned on a carbon number basis of one (C1).
7.5.4.   Preparation of the particulate sampling filter
At least one hour before the test, the 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 stabilisation. At the end of the stabilisation period, the filter shall be weighed and the tare 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.
7.5.5.   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).
7.5.6.   Starting the particulate sampling system
The particulate sampling system shall be started and operated on by-pass. The particulate background level of the diluent may be determined by sampling the diluent prior to the entrance of the exhaust gas into the dilution tunnel. The measurement may be done prior to or after the test. If the measurement is done both at the beginning and at the end of the cycle, the values may be averaged. If a different sampling system is used for background measurement, the measurement shall be done in parallel to the test run.
7.6.   WHTC cycle run
7.6.1.   Engine cool-down
A natural or forced cool-down procedure may be applied. For forced cool-down, good engineering judgment shall be used to set up systems to send cooling air across the engine, to send cool oil through the engine lubrication system, to remove heat from the coolant through the engine cooling system, and to remove heat from an exhaust after-treatment system. In the case of a forced after-treatment system cool down, cooling air shall not be applied until the after-treatment system has cooled below its catalytic activation temperature. Any cooling procedure that results in unrepresentative emissions is not permitted.
7.6.2.   Cold start test
The cold-start test shall be started when the temperatures of the engine’s lubricant, coolant, and after-treatment systems are all between 293 and 303 K (20 and 30 °C). The engine shall be started using one of the following methods:






(a)


the engine shall be started as recommended in the owners manual using a production starter motor and adequately charged battery or a suitable power supply, or










(b)


the engine shall be started by using the dynamometer. The engine shall be motored within ± 25 per cent of its typical in-use cranking speed. Cranking shall be stopped within 1 second after the engine is running. If the engine does not start after 15 seconds of cranking, cranking shall be stopped and the reason for the failure to start determined, unless the owners manual or the service-repair manual describes the longer cranking time as normal.




7.6.3.   Hot soak period
Immediately upon completion of the cold start test, the engine shall be conditioned for the hot start test using a 10 ± 1 minutes hot soak period.
7.6.4.   Hot start test
The engine shall be started at the end of the hot soak period as defined in paragraph 7.6.3. using the starting methods given in paragraph 7.6.2.
7.6.5.   Test sequence
The test sequence of both cold start and hot start test shall commence at the start of the engine. After the engine is running, cycle control shall be initiated so that engine operation matches the first set point of the cycle.
The WHTC shall be performed according to the reference cycle as set out in paragraph 7.4. 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 interpolation between the 1 Hz set points of the reference cycle. Actual engine speed and torque shall be recorded at least once every second during the test cycle (1 Hz), and the signals may be electronically filtered.
7.6.6.   Collection of emission relevant data
At the start of the test sequence, the measuring equipment shall be started, simultaneously:






(a)


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










(b)


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










(c)


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










(d)


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










(e)


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




If raw exhaust measurement is used, the emission concentrations ((NM)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 analysers 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 analyser 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, CO2, and NMHC may be determined by integration of continuous measurement signals or by analysing the concentrations in the sample bag, collected over the cycle. The concentrations of the gaseous pollutants in the diluent shall be determined prior to the point where the exhaust enters into the dilution tunnel by integration or by collecting into the background bag. All other parameters that need to be measured shall be recorded with a minimum of one measurement per second (1 Hz).
7.6.7.   Particulate sampling
At the start of the test sequence, 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 controlled, so that the flow rate through the particulate sample probe or transfer tube is maintained proportional to the exhaust mass flow rate as determined in accordance with paragraph 9.4.6.1.
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 ±2,5 per cent of the set flow rate. If flow compensation (i.e. proportional control of sample flow) is used, it shall be demonstrated that the ratio of main tunnel flow to particulate sample flow does not change by more than ±2,5 per cent of its set value (except for the first 10 seconds of sampling). 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 ±2,5 per cent because of high particulate loading on the filter, the test shall be voided. The test shall be rerun using a lower sample flow rate.
7.6.8.   Engine stalling and equipment malfunction
If the engine stalls anywhere during the cold start test, the test shall be voided. The engine shall be preconditioned and restarted according to the requirements of paragraph 7.6.2, and the test repeated.
If the engine stalls anywhere during the hot start test, the hot start test shall be voided. The engine shall be soaked according to paragraph 7.6.3, and the hot start test repeated. In this case, the cold start test need not be repeated.
If a malfunction occurs in any of the required test equipment during the test cycle, the test shall be voided and repeated in line with the above provisions.
7.7.   WHSC cycle run
7.7.1.   Preconditioning the dilution system and the engine
The dilution system and the engine shall be started and warmed up in accordance with paragraph 7.4.1. After warm-up, the engine and sampling system shall be preconditioned by operating the engine at mode 9 (see paragraph 7.2.2, table 1) for a minimum of 10 minutes while simultaneously operating the dilution system. Dummy particulate emissions samples may be collected. Those sample filters need not be stabilised or weighed, and may be discarded. Flow rates shall be set at the approximate flow rates selected for testing. The engine shall be shut off after preconditioning.
7.7.2.   Engine starting
5 ± 1 minutes after completion of preconditioning at mode 9 as described in paragraph 7.7.1, the engine shall be started according to the manufacturer’s recommended starting procedure in the owner’s manual, using either a production starter motor or the dynamometer in accordance with paragraph 7.6.2.
7.7.3.   Test sequence
The test sequence shall commence after the engine is running and within one minute after engine operation is controlled to match the first mode of the cycle (idle).
The WHSC shall be performed according to the order of test modes listed in table 1 of paragraph 7.2.2.
7.7.4.   Collection of emission relevant data
At the start of the test sequence, the measuring equipment shall be started, simultaneously:






(a)


start collecting or analysing diluent, if a full flow dilution system is used;










(b)


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










(c)


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










(d)


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










(e)


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




If raw exhaust measurement is used, the emission concentrations ((NM)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 analysers 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 analyser 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, CO2, and NMHC may be determined by integration of continuous measurement signals or by analysing the concentrations in the sample bag, collected over the cycle. The concentrations of the gaseous pollutants in the diluent shall be determined prior to the point where the exhaust enters into the dilution tunnel by integration or by collecting into the background bag. All other parameters that need to be measured shall be recorded with a minimum of one measurement per second (1 Hz).
7.7.5.   Particulate sampling
At the start of the test sequence, 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 controlled, so that the flow rate through the particulate sample probe or transfer tube is maintained proportional to the exhaust mass flow rate as determined in accordance with paragraph 9.4.6.1.
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 ±2,5 per cent of the set flow rate. If flow compensation (i.e. proportional control of sample flow) is used, it shall be demonstrated that the ratio of main tunnel flow to particulate sample flow does not change by more than ±2,5 per cent of its set value (except for the first 10 seconds of sampling). 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 ±2,5 per cent because of high particulate loading on the filter, the test shall be voided. The test shall be rerun using a lower sample flow rate.
7.7.6.   Engine stalling and equipment malfunction
If the engine stalls anywhere during the cycle, the test shall be voided. The engine shall be preconditioned according to paragraph 7.7.1 and restarted according to paragraph 7.7.2, and the test repeated.
If a malfunction occurs in any of the required test equipment during the test cycle, the test shall be voided and repeated in line with the above provisions.
7.8.   Post-test procedures
7.8.1.   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 analyser system, sampling shall continue until system response times have elapsed.
7.8.2.   Verification of proportional sampling
For any proportional batch sample, such as a bag sample or PM sample, it shall be verified that proportional sampling was maintained according to paragraphs 7.6.7 and 7.7.5. Any sample that does not fulfil the requirements shall be voided.
7.8.3.   PM conditioning and weighing
The particulate filter shall be placed into covered or sealed containers or the filter holders shall be closed, in order to protect the sample filters against ambient contamination. Thus protected, the filter shall be returned to the weighing chamber. The filter shall be conditioned for at least one hour, and then weighed according to paragraph 9.4.5. The gross weight of the filter shall be recorded.
7.8.4.   Drift verification
As soon as practical but no later than 30 minutes after the test cycle is complete or during the soak period, the zero and span responses of the gaseous analyser ranges used shall be determined. For the purpose of this paragraph, test cycle is defined as follows:






(a)


for the WHTC: the complete sequence cold — soak — hot;










(b)


for the WHTC hot start test (paragraph 6.6): the sequence soak — hot;










(c)


for the multiple regeneration WHTC hot start test (paragraph 6.6): the total number of hot start tests;










(d)


for the WHSC: the test cycle.




The following provisions apply for analyser drift:






(a)


the pre-test zero and span and post-test zero and span responses may be directly inserted into equation 66 of paragraph 8.6.1 without determining drift;










(b)


if the drift difference between the pre-test and post-test results is less than 1 per cent of full scale, the measured concentrations may be used uncorrected or may be corrected for drift according to paragraph 8.6.1;










(c)


if the drift difference between the pre-test and post-test results is equal to or greater than 1 per cent of full scale, the test shall be voided or the measured concentrations shall be corrected for drift according to paragraph 8.6.1.




7.8.5.   Analysis of gaseous bag sampling
As soon as practical, the following shall be performed:






(a)


gaseous bag samples shall be analysed no later than 30 minutes after the hot start test is complete or during the soak period for the cold start test;










(b)


background samples shall be analysed no later than 60 minutes after the hot start test is complete.




7.8.6.   Validation of cycle work
Before calculating actual cycle work, any points recorded during engine starting shall be omitted. Actual cycle work shall be determined over the test cycle by synchronously using actual speed and actual torque values to calculate instantaneous values for engine power. Instantaneous engine power values shall be integrated over the test cycle to calculate the actual cycle work W
act (kWh). If auxiliaries/equipment are not fitted in accordance with paragraph 6.3.1, the instantaneous power values shall be corrected using equation (4) in paragraph 6.3.5.
The same methodology as described in paragraph 7.4.8 shall be used for integrating actual engine power.
The actual cycle work W
act is used for comparison to the reference cycle work W
ref and for calculating the brake specific emissions (see paragraph 8.6.3).

W
act shall be between 85 per cent and 105 per cent of W
ref.
7.8.7.   Validation statistics of the test cycle
Linear regressions of the actual values (n
act, M
act, P
act) on the reference values (n
ref, M
ref, P
ref) shall be performed for both the WHTC and the WHSC.
To minimise the biasing effect of the time lag between the actual and reference cycle values, the entire engine speed and torque actual signal sequence may be advanced or delayed in time with respect to the reference speed and torque sequence. If the actual signals are shifted, both speed and torque shall be shifted the same amount in the same direction.
The method of least squares shall be used, with the best-fit equation having the form:



 (11)
where:







y



is the actual value of speed (min–1), torque (Nm), or power (kW)





a1




is the slope of the regression line





x



is the reference value of speed (min–1), torque (Nm), or power (kW)





a0




is the y intercept of the regression line




The standard error of estimate (SEE) 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 Hz. For a test to be considered valid, the criteria of table 2 (WHTC) or table 3 (WHSC) shall be met.
Table 2
Regression line tolerances for the WHTC








 


Speed


Torque


Power




Standard error of estimate (SEE) of y on x


maximum 5 per cent of maximum test speed


maximum 10 per cent of maximum engine torque


maximum 10 per cent of maximum engine power




Slope of the regression line, a1



0,95 to 1,03


0,83 – 1,03


0,89 – 1,03




Coefficient of determination, r2



minimum 0,970


minimum 0,850


minimum 0,910




y intercept of the regression line, a0



maximum 10 per cent of idle speed


± 20 Nm or ± 2 per cent of maximum torque whichever is greater


± 4 kW or ± 2 per cent of maximum power whichever is greater







Table 3
Regression line tolerances for the WHSC








 


Speed


Torque


Power




Standard error of estimate (SEE) of y on x


maximum 1 per cent of maximum test speed


maximum 2 per cent of maximum engine torque


maximum 2 per cent of maximum engine power




Slope of the regression line, a1



0,99 to 1,01


0,98 – 1,02


0,98 – 1,02




Coefficient of determination, r2



minimum 0,990


minimum 0,950


minimum 0,950




y intercept of the regression line, a0



maximum 1 per cent of maximum test speed


± 20 Nm or ± 2 per cent of maximum torque whichever is greater


± 4 kW or ± 2 per cent of maximum power whichever is greater




For regression purposes only, point omissions are permitted where noted in table 4 before doing the regression calculation. However, those points shall not be omitted for the calculation of cycle work and emissions. Point omission may be applied to the whole or to any part of the cycle.
Table 4
Permitted point omissions from regression analysis







Event


Conditions


Permitted point omissions




Minimum operator demand (idle point)



n
ref = 0 per cent
and

M
ref = 0 per cent
and

M
act > (M
ref – 0,02 M
max. mapped torque)
and

M
act < (M
ref + 0,02 M
max. mapped torque)


speed and power




Minimum operator demand (motoring point)



M
ref < 0 per cent


power and torque




Minimum operator demand



n
act ≤ 1,02 n
ref and M
act > M
ref

or

n
act > n
ref and M
act ≤ M
ref'
or

n
act > 1,02 n
ref and M
ref < M
act ≤ (M
ref + 0,02M
max. mapped torque)


power and either torque or speed




Maximum operator demand



n
act < n
ref and M
act ≥ M
ref

or

n
act ≥ 0,98 n
ref and M
act < M
ref

or

n
act < 0,98 n
ref and M
ref > M
act ≥ (M
ref – 0,02M
max. mapped torque)


power and either torque or speed




8.   EMISSION CALCULATION
The final test result shall be rounded in one step to the number of places to the right of the decimal point indicated by the applicable emission standard plus one additional significant figure, in accordance with ASTM E 29-06B. No rounding of intermediate values leading to the final break-specific emission result is permitted.
Examples of the calculation procedures are given in Appendix 6.
Emissions calculation on a molar basis, in accordance with Annex 7 of gtr No [xx] concerning the exhaust emission test protocol for Non-Road Mobile Machinery (NRMM), is permitted with the prior agreement of the type approval authority.
8.1.   Dry/wet correction
If the emissions are measured on a dry basis, the measured concentration shall be converted to a wet basis according to the following equation:



 (12)
where:







c
d



is the dry concentration in ppm or per cent volume





kw




is the dry/wet correction factor (k
w,a, k
w,e, or k
w,d depending on respective equation used)




8.1.1.   Raw exhaust gas



 (13)
or



 (14)
or



 (15)
with



 (16)
and



 (17)
where:







H
a



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





w
ALF



is the hydrogen content of the fuel, per cent mass





q
mf,i



is the instantaneous fuel mass flow rate, kg/s





q
mad,I



is the instantaneous dry intake air mass flow rate, kg/s





p
r



is the water vapour pressure after cooling bath, kPa





p
b



is the total atmospheric pressure, kPa





w
DEL



is the nitrogen content of the fuel, per cent mass





w
EPS



is the oxygen content of the fuel, per cent mass





α



is the molar hydrogen ratio of the fuel





c
CO2



is the dry CO2 concentration, per cent





c
CO



is the dry CO concentration, per cent




Equations (13) and (14) are principally identical with the factor 1,008 in equations (13) and (15) being an approximation for the more accurate denominator in equation (14).
8.1.2.   Diluted exhaust gas



 (18)
or



 (19)
with



 (20)
where:







α



is the molar hydrogen ratio of the fuel





c
CO2w



is the wet CO2 concentration, per cent





c
CO2d



is the dry CO2 concentration, per cent





H
d



is the diluent humidity, g water per kg dry air





H
a



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





D



is the dilution factor (see paragraph 8.5.2.3.2)




8.1.3.   Diluent



 (21)
with



 (22)
where:







H
d



is the diluent humidity, g water per kg dry air




8.2.   NOx correction for humidity
As the NOx emission depends on ambient air conditions, the NOx concentration shall be corrected for humidity with the factors given in paragraph 8.2.1 or 8.2.2. The intake air humidity Ha may be derived from relative humidity measurement, dew point measurement, vapour pressure measurement or dry/wet bulb measurement using generally accepted equations.
8.2.1.   Compression-ignition engines



 (23)
where:







H
a



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




8.2.2.   Positive ignition engines



 (24)
where:







H
a



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




8.3.   Particulate filter buoyancy correction
The sampling filter mass shall be corrected for its buoyancy in air. The buoyancy correction depends on sampling filter density, air density and the density of the balance calibration weight, and does not account for the buoyancy of the PM itself. The buoyancy correction shall be applied to both tare filter mass and gross filter mass.
If the density of the filter material is not known, the following densities shall be used:






(a)


teflon coated glass fiber filter: 2 300 kg/m3











(b)


teflon membrane filter: 2 144 kg/m3











(c)


teflon membrane filter with polymethylpentene support ring: 920 kg/m3





For stainless steel calibration weights, a density of 8 000 kg/m3 shall be used. If the material of the calibration weight is different, its density shall be known.
The following equation shall be used:



 (25)
with



 (26)
where:







m
uncor



is the uncorrected particulate filter mass, mg





ρ
a



is the density of the air, kg/m3






ρ
w



is the density of balance calibration weight, kg/m3






ρ
f



is the density of the particulate sampling filter, kg/m3






p
b



is the total atmospheric pressure, kPa





T
a



is the air temperature in the balance environment, K




28,836


is the molar mass of the air at reference humidity (282,5 K), g/mol




8,3144


is the molar gas constant




The particulate sample mass mp used in paragraphs 8.4.3 and 8.5.3 shall be calculated as follows:



 (27)
where:







m
f,G



is the buoyancy corrected gross particulate filter mass, mg





m
f,T



is the buoyancy corrected tare particulate filter mass, mg




8.4.   Partial flow dilution (PFS) and raw gaseous measurement
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 of intake air and fuel flow measurement, tracer method or 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 shall be checked by applying a regression analysis between sample and exhaust flow in accordance with paragraph 9.4.6.1. The complete test set up is schematically shown in figure 6.




Figure 6


Scheme of raw/partial flow measurement system

Exhaust sample
Flow measurement
Signals for system control and computation
Exhaust flow
Dilution air
Flow control
Partial flow dilution system
Exhaust
Exhaust gas analyzer
Computation
Computer system
Fuel flow
Engine
Intake air flow
8.4.1.   Determination of exhaust gas mass flow
8.4.1.1.   Introduction
For calculation of the emissions in the raw exhaust gas and for controlling of a partial flow dilution system, it is necessary to know the exhaust gas mass flow rate. For the determination of the exhaust mass flow rate, either of the methods described in paragraphs 8.4.1.3 to 8.4.1.7 may be used.
8.4.1.2.   Response time
For the purpose of emissions calculation, the response time of either method described in paragraphs 8.4.1.3 to 8.4.1.7 shall be equal to or less than the analyser response time of ≤ 10 s, as required in paragraph 9.3.5.
For the purpose of controlling of a partial flow dilution system, a faster response is required. For partial flow dilution systems with online control, the response time shall be ≤ 0,3 s. For partial flow dilution systems with look-ahead control based on a pre-recorded test run, the response time of the exhaust flow measurement system shall be ≤ 5 s with a rise time of ≤ 1 s. The system response time shall be specified by the instrument manufacturer. The combined response time requirements for the exhaust gas flow and partial flow dilution system are indicated in paragraph 9.4.6.1.
8.4.1.3.   Direct measurement method
Direct measurement of the instantaneous exhaust flow shall be done by systems, such as:






(a)


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










(b)


ultrasonic flowmeter;










(c)


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 shall not be affected by the installation of the device.
The flowmeters shall meet the linearity requirements of paragraph 9.2.
8.4.1.4.   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 shall be as follows:



 (28)
where:







q

mew,i



is the instantaneous exhaust mass flow rate, kg/s





q

maw,i



is the instantaneous intake air mass flow rate, kg/s





q

mf,i



is the instantaneous fuel mass flow rate, kg/s




The flowmeters shall meet the linearity requirements of paragraph 9.2, but shall be accurate enough to also meet the linearity requirements for the exhaust gas flow.
8.4.1.5.   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 shall 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 analyser.
The calculation of the exhaust gas flow shall be as follows:



 (29)
where:







q

mew,i



is the instantaneous exhaust mass flow rate, kg/s





q

vt



is tracer gas flow rate, cm3/min





c
mix,i



is the instantaneous concentration of the tracer gas after mixing, ppm





ρ
e



is the density of the exhaust gas, kg/m3 (cf. table 4)





c
b



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




The background concentration of the tracer gas (c
b) 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 per cent of the concentration of the tracer gas after mixing (c
mix.i) at maximum exhaust flow, the background concentration may be neglected.
The total system shall meet the linearity requirements for the exhaust gas flow of paragraph 9.2.
8.4.1.6.   Airflow 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:



 (30)
with



 (31)



 (32)
where:







q

maw,i



is the instantaneous intake air mass flow rate, kg/s





A/F
st



is the stoichiometric air to fuel ratio, kg/kg





λ
i



is the instantaneous excess air ratio





c
CO2d



is the dry CO2 concentration, per cent





c
COd



is the dry CO concentration, ppm





c
HCw



is the wet HC concentration, ppm




Airflowmeter and analysers shall meet the linearity requirements of paragraph 9.2, and the total system shall meet the linearity requirements for the exhaust gas flow of paragraph 9.2.
If an air to fuel ratio measurement equipment such as a zirconia-type sensor is used for the measurement of the excess air ratio, it shall meet the specifications of paragraph 9.3.2.7.
8.4.1.7.   Carbon balance method
This involves exhaust mass calculation from the fuel flow and the gaseous exhaust components that include carbon. The calculation of the instantaneous exhaust gas mass flow is as follows:



 (33)
with



 (34)
and



 (35)
where:







q
mf,i



is the instantaneous fuel mass flow rate, kg/s





H
a



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





w
BET



is the carbon content of the fuel, per cent mass





w
ALF



is the hydrogen content of the fuel, per cent mass





w
DEL



is the nitrogen content of the fuel, per cent mass





w
EPS



is the oxygen content of the fuel, per cent mass





c
CO2d



is the dry CO2 concentration, per cent





c
CO2d,a



is the dry CO2 concentration of the intake air, per cent





c
CO



is the dry CO concentration, ppm





c
HCw



is the wet HC concentration, ppm




8.4.2.   Determination of the gaseous components
8.4.2.1.   Introduction
The gaseous components in the raw exhaust gas emitted by the engine submitted for testing shall be measured with the measurement and sampling systems described in paragraph 9.3 and Appendix 3. The data evaluation is described in paragraph 8.4.2.2.
Two calculation procedures are described in paragraphs 8.4.2.3 and 8.4.2.4, which are equivalent for the reference fuel of Appendix 2. The procedure in paragraph 8.4.2.3 is more straightforward, since it uses tabulated u values for the ratio between component and exhaust gas density. The procedure in paragraph 8.4.2.4 is more accurate for fuel qualities that deviate from the specifications in Appendix 2, but requires elementary analysis of the fuel composition.
8.4.2.2.   Data evaluation
The emission relevant data shall be recorded and stored in accordance with paragraph 7.6.6.
For calculation of the mass emission of the gaseous components, the traces of the recorded concentrations and the trace of the exhaust gas mass flow rate shall be time aligned by the transformation time as defined in paragraph 3.1.30. Therefore, the response time of each gaseous emissions analyser and of the exhaust gas mass flow system shall be determined according to paragraphs 8.4.1.2 and 9.3.5, respectively, and recorded.
8.4.2.3.   Calculation of mass emission based on tabulated values
The mass of the pollutants (g/test) shall be determined by calculating the instantaneous mass emissions from the raw concentrations of the pollutants and the exhaust gas mass flow, aligned for the transformation time as determined in accordance with paragraph 8.4.2.2, integrating the instantaneous values over the cycle, and multiplying the integrated values with the u values from table 5. If measured on a dry basis, the dry/wet correction according to paragraph 8.1 shall be applied to the instantaneous concentration values before any further calculation is done.
For the calculation of NOx, the mass emission shall be multiplied, where applicable, with the humidity correction factor k
h,D, or k
h,G, as determined according to paragraph 8.2.
The following equation shall be applied:



 (in g/test) (36)
where:







u
gas



is the respective value of the exhaust component from table 5





c
gas,i



is the instantaneous concentration of the component in the exhaust gas, ppm





q

mew,i



is the instantaneous exhaust mass flow, kg/s





f



is the data sampling rate, Hz





n



is the number of measurements




Table 5
Raw exhaust gas u values and component densities












Fuel



ρ
e



Gas




NOx



CO


HC


CO2



O2



CH4






ρ
gas [kg/m3]




2,053


1,250



 (1)



1,9636


1,4277


0,716





u
gas
 (2)





Diesel


1,2943


0,001586


0,000966


0,000479


0,001517


0,001103


0,000553




Ethanol


1,2757


0,001609


0,000980


0,000805


0,001539


0,001119


0,000561




CNG (3)



1,2661


0,001621


0,000987


0,000528 (4)



0,001551


0,001128


0,000565




Propane


1,2805


0,001603


0,000976


0,000512


0,001533


0,001115


0,000559




Butane


1,2832


0,001600


0,000974


0,000505


0,001530


0,001113


0,000558




LPG (5)



1,2811


0,001602


0,000976


0,000510


0,001533


0,001115


0,000559




8.4.2.4.   Calculation of mass emission based on exact equations
The mass of the pollutants (g/test) shall be determined by calculating the instantaneous mass emissions from the raw concentrations of the pollutants, the u values and the exhaust gas mass flow, aligned for the transformation time as determined in accordance with paragraph 8.4.2.2 and integrating the instantaneous values over the cycle. If measured on a dry basis, the dry/wet correction according to paragraph 8.1 shall be applied to the instantaneous concentration values before any further calculation is done.
For the calculation of NOx, the mass emission shall be multiplied with the humidity correction factor k
h,D, or k
h,G, as determined according to paragraph 8.2.
The following equation shall be applied:



 (in g/test) (37)
where:







u
gas,i



is calculated from equation 38 or 39





c
gas,i



is the instantaneous concentration of the component in the exhaust gas, ppm





q

mew,i



is the instantaneous exhaust mass flow, kg/s





f



is the data sampling rate, Hz





n



is the number of measurements




The instantaneous u values shall be calculated as follows:



 (38)
or



 (39)
with



 (40)
where:







M
gas



is the molar mass of the gas component, g/mol (cf. Appendix 6)





M
e,i




is the instantaneous molar mass of the exhaust gas, g/mol





ρ
gas



is the density of the gas component, kg/m3






ρ
e,i



is the instantaneous density of the exhaust gas, kg/m3





The molar mass of the exhaust, M
e, shall be derived for a general fuel composition CH
α
O
ε
N
δ
S
γ
 under the assumption of complete combustion, as follows:



 (41)
where:







q

maw,i



is the instantaneous intake air mass flow rate on wet basis, kg/s





q

mf,i



is the instantaneous fuel mass flow rate, kg/s





H
a



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





M
a



is the molar mass of the dry intake air = 28,965 g/mol




The exhaust density ρ
e shall be derived, as follows:



 (42)
where:







q

mad,i



is the instantaneous intake air mass flow rate on dry basis, kg/s





q

mf,i



is the instantaneous fuel mass flow rate, kg/s





H
a



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





k
fw



is the fuel specific factor of wet exhaust (equation 16) in paragraph 8.1.1.




8.4.3.   Particulate determination
8.4.3.1.   Data evaluation
The particulate mass shall be calculated according to equation 27 of paragraph 8.3. For the evaluation of the particulate concentration, the total sample mass (m
sep) through the filter over the test cycle shall be recorded.
With the prior approval of the type approval authority, the particulate mass may be corrected for the particulate level of the diluent, as determined in paragraph 7.5.6, in line with good engineering practice and the specific design features of the particulate measurement system used.
8.4.3.2.   Calculation of mass emission
Depending on system design, the mass of particulates (g/test) shall be calculated by either of the methods in paragraphs 8.4.3.2.1 or 8.4.3.2.2 after buoyancy correction of the particulate sample filter according to paragraph 8.3.
8.4.3.2.1.   Calculation based on sample ratio



 (43)
where:







m
p



is the particulate mass sampled over the cycle, mg





r
s



is the average sample ratio over the test cycle




with



 (44)
where:







m
se



is the sample mass over the cycle, kg





m
ew



is the total exhaust mass flow over the cycle, kg





m
sep



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





m
sed



is the mass of diluted exhaust gas passing the dilution tunnel, kg




In case of the total sampling type system, m
sep and m
sed are identical.
8.4.3.2.2.   Calculation based on dilution ratio



 (45)
where:







m
p



is the particulate mass sampled over the cycle, mg





m
sep



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





m
edf



is the 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:



 (46)



 (47)



 (48)
where:







q

medf,i



is the instantaneous equivalent diluted exhaust mass flow rate, kg/s





q

mew,i



is the instantaneous exhaust mass flow rate, kg/s





r
d,i



is the instantaneous dilution ratio





q

mdew,i



is the instantaneous diluted exhaust mass flow rate, kg/s





q

mdw,i



is the instantaneous diluent mass flow rate, kg/s





f



is the data sampling rate, Hz





n



is the number of measurements




8.5.   Full flow dilution measurement (CVS)
The concentration signals, either by integration over the cycle or by bag sampling, of the gaseous components shall be used for the calculation of the mass emissions by multiplication with the diluted exhaust mass flow rate. The exhaust mass flow rate shall be measured with a constant volume sampling (CVS) system, which may use a positive displacement pump (PDP), a critical flow venturi (CFV) or a subsonic venturi (SSV) with or without flow compensation.
For bag sampling and particulate sampling, a proportional sample shall be taken from the diluted exhaust gas of the CVS system. For a system without flow compensation, the ratio of sample flow to CVS flow shall not vary by more than ±2,5 per cent from the set point of the test. For a system with flow compensation, each individual flow rate shall be constant within ±2,5 per cent of its respective target flow rate.
The complete test set up is schematically shown in figure 7.




Figure 7


Scheme of full flow measurement system

Exhaust sample
Flow measurement
Signals for system control and computation
Dilution air
Particulate measurement system
Computation
Diluted exhaust flow
Computer system
Dilution air
Dilution tunnel
Exhaust
or
Sample bag
Exhaust gas analyzer
Engine
Computation
Background bag
8.5.1.   Determination of the diluted exhaust gas flow
8.5.1.1.   Introduction
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 (V
0 for PDP, K
V for CFV, C
d for SSV) by either of the methods described in paragraphs 8.5.1.2 to 8.5.1.4. If the total sample flow of particulates (m
sep) exceeds 0,5 per cent of the total CVS flow (m
ed), the CVS flow shall be corrected for m
sep or the particulate sample flow shall be returned to the CVS prior to the flow measuring device.
8.5.1.2.   PDP-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:



 (49)
where:







V
0



is the volume of gas pumped per revolution under test conditions, m3/rev





n
P



is the total revolutions of pump per test





p
p



is the absolute pressure at pump inlet, kPa





T



is the average temperature of the diluted exhaust gas at pump inlet, 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:



 (50)
where:







n
P,i



is the total revolutions of pump per time interval




8.5.1.3.   CFV-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:



 (51)
where:







t



is the cycle time, s





K
V



is the calibration coefficient of the critical flow venturi for standard conditions,





p
p



is the absolute pressure at venturi inlet, kPa





T



is the absolute temperature at venturi inlet, 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:



 (52)
where:






Δti



is the time interval, s




8.5.1.4.   SSV-CVS system
The calculation of the mass flow over the cycle shall be as follows, if the temperature of the diluted exhaust is kept within ± 11 K over the cycle by using a heat exchanger:



 (53)
with



 (54)
where:







A
0



is 0,006111 in SI units of 








d
V



is the diameter of the SSV throat, m





C
d



is the discharge coefficient of the SSV





p
p



is the absolute pressure at venturi inlet, kPa





T



is the temperature at the venturi inlet, K





r
p



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








r
D



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



 (55)
where:






Δt
i



is the time interval, s




The real time calculation shall be initialised with either a reasonable value for C
d, such as 0,98, or a reasonable value of Q
ssv. If the calculation is initialised with Q
ssv, the initial value of Q
ssv shall be used to evaluate the Reynolds number.
During all emissions tests, the Reynolds number at the SSV throat shall be in the range of Reynolds numbers used to derive the calibration curve developed in paragraph 9.5.4.
8.5.2.   Determination of the gaseous components
8.5.2.1.   Introduction
The gaseous components in the diluted exhaust gas emitted by the engine submitted for testing shall be measured by the methods described in Appendix 3. Dilution of the exhaust shall be done with filtered ambient air, synthetic air or nitrogen. The flow capacity of the full flow system shall be large enough to completely eliminate water condensation in the dilution and sampling systems. Data evaluation and calculation procedures are described in paragraphs 8.5.2.2 and 8.5.2.3.
8.5.2.2.   Data evaluation
The emission relevant data shall be recorded and stored in accordance with paragraph 7.6.6.
8.5.2.3.   Calculation of mass emission
8.5.2.3.1.   Systems with constant mass flow
For systems with heat exchanger, the mass of the pollutants shall be determined from the following equation:



 (in g/test) (56)
where:







u
gas



is the respective value of the exhaust component from table 6





c
gas



is the average background corrected concentration of the component, ppm





m
ed



is the total diluted exhaust mass over the cycle, kg




If measured on a dry basis, the dry/wet correction according to paragraph 8.1 shall be applied.
For the calculation of NOx, the mass emission shall be multiplied, if applicable, with the humidity correction factor k
h,D, or k
h,G, as determined according to paragraph 8.2.
The u values are given in table 6. For calculating the u
gas values, the density of the diluted exhaust gas has been assumed to be equal to air density. Therefore, the u
gas values are identical for single gas components, but different for HC.
Table 6
Diluted exhaust gas u values and component densities












Fuel



ρ
de



Gas




NOx



CO


HC


CO2



O2



CH4






ρ
gas [kg/m3]




2,053


1,250



 (6)



1,9636


1,4277


0,716





u
gas
 (7)





Diesel


1,293


0,001588


0,000967


0,000480


0,001519


0,001104


0,000553




Ethanol


1,293


0,001588


0,000967


0,000795


0,001519


0,001104


0,000553




CNG (8)



1,293


0,001588


0,000967


0,000517 (9)



0,001519


0,001104


0,000553




Propane


1,293


0,001588


0,000967


0,000507


0,001519


0,001104


0,000553




Butane


1,293


0,001588


0,000967


0,000501


0,001519


0,001104


0,000553




LPG (10)



1,293


0,001588


0,000967


0,000505


0,001519


0,001104


0,000553




Alternatively, the u values may be calculated using the exact calculation method generally described in paragraph 8.4.2.4, as follows:



 (57)
where:







M
gas



is the molar mass of the gas component, g/mol (cf. Appendix 6)





M
e



is the molar mass of the exhaust gas, g/mol





M
d



is the molar mass of the diluent = 28,965 g/mol





D



is the dilution factor (see paragraph 8.5.2.3.2)




8.5.2.3.2.   Determination of the background corrected concentrations
The average background concentration of the gaseous pollutants in the diluent shall be subtracted from the 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 equation shall be used:



 (58)
where:







c
gas,e



is the concentration of the component measured in the diluted exhaust gas, ppm





c
d



is the concentration of the component measured in the diluent, ppm





D



is the dilution factor




The dilution factor shall be calculated as follows:






(a)


for diesel and LPG fuelled gas engines



 (59)










(b)


for NG fuelled gas engines



 (60)




where:







c
CO2,e



is the wet concentration of CO2 in the diluted exhaust gas, per cent vol





c
HC,e



is the wet concentration of HC in the diluted exhaust gas, ppm C1





c
NMHC,e



is the wet concentration of NMHC in the diluted exhaust gas, ppm C1





c
CO,e



is the wet concentration of CO in the diluted exhaust gas, ppm





F
S



is the stoichiometric factor




The stoichiometric factor shall be calculated as follows:



 (61)
where:







α



is the molar hydrogen ratio of the fuel (H/C)




Alternatively, if the fuel composition is not known, the following stoichiometric factors may be used:








F
S (diesel)


=


13,4





F
S (LPG)


=


11,6





F
S (NG)


=


9,5




8.5.2.3.3.   Systems with flow compensation
For systems without heat exchanger, the mass of the pollutants (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 equation shall be applied:



 (62)
where:







c
gas,e



is the concentration of the component measured in the diluted exhaust gas, ppm





c
d



is the concentration of the component measured in the diluent, ppm





m
ed,i



is the instantaneous mass of the diluted exhaust gas, kg





m
ed



is the total mass of diluted exhaust gas over the cycle, kg





u
gas



is the tabulated value from table 6





D



is the dilution factor




8.5.3.   Particulate determination
8.5.3.1.   Calculation of mass emission
The particulate mass (g/test) shall be calculated after buoyancy correction of the particulate sample filter according to paragraph 8.3, as follows:



 (63)
where:







m
p



is the particulate mass sampled over the cycle, mg





m
sep



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





m
ed



is the mass of diluted exhaust gas over the cycle, kg




with



 (64)
where:







m
set



is the mass of double diluted exhaust gas through particulate filter, kg





m
ssd



is the mass of secondary diluent, kg




If the particulate background level of the diluent is determined in accordance with paragraph 7.5.6, the particulate mass may be background corrected. In this case, the particulate mass (g/test) shall be calculated as follows:



 (65)
where:







m
sep



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





m
ed



is the mass of diluted exhaust gas over the cycle, kg





m
sd



is the mass of diluent sampled by background particulate sampler, kg





m
b



is the mass of the collected background particulates of the diluent, mg





D



is the dilution factor as determined in paragraph 8.5.2.3.2.




8.6.   General calculations
8.6.1.   Drift correction
With respect to drift verification in paragraph 7.8.4, the corrected concentration value shall be calculated as follows:



 (66)
where:







c
ref,z



is the reference concentration of the zero gas (usually zero), ppm





c
ref,s



is the reference concentration of the span gas, ppm





c
pre,z



is the pre-test analyser concentration of the zero gas, ppm





c
pre,s



is the pre-test analyser concentration of the span gas, ppm,





c
post,z



is the post-test analyser concentration of the zero gas, ppm,





c
post,s



is the post-test analyser concentration of the span gas, ppm





cgas




is the sample gas concentration, ppm




Two sets of specific emission results shall be calculated for each component in accordance with paragraph 8.6.3, after any other corrections have been applied. One set shall be calculated using uncorrected concentrations and another set shall be calculated using the concentrations corrected for drift according to equation 66.
Depending on the measurement system and calculation method used, the uncorrected emissions results shall be calculated with equations 36, 37 56, 57 or 62, respectively. For calculation of the corrected emissions, c
gas in equations 36, 37 56, 57 or 62, respectively, shall be replaced with c
cor of equation 66. If instantaneous concentration values c
gas,i are used in the respective equation, the corrected value shall also be applied as instantaneous value c
cor,i. In equation 57, the correction shall be applied to both the measured and the background concentration.
The comparison shall be made as a percentage of the uncorrected results. The difference between the uncorrected and the corrected brake-specific emission values shall be within ± 4 per cent of the uncorrected brake-specific emission values or within ± 4 per cent of the respective limit value, whichever is greater. If the drift is greater than 4 per cent, the test shall be voided.
If drift correction is applied, only the drift-corrected emission results shall be used when reporting emissions.
8.6.2.   Calculation of NMHC and CH4

The calculation of NMHC and CH4 depends on the calibration method used. The FID for the measurement without NMC (lower path of Appendix 3, figure 11), shall be calibrated with propane. For the calibration of the FID in series with NMC (upper path of Appendix 3, figure 11), the following methods are permitted.






(a)


calibration gas — propane; propane bypasses NMC,










(b)


calibration gas — methane; methane passes through NMC




The concentration of NMHC and CH4 shall be calculated as follows for (a):



 (67)



 (68)
The concentration of NMHC and CH4 shall be calculated as follows for (b):



 (67a)



 (68a)
where:







c
HC(w/NMC)



is the HC concentration with sample gas flowing through the NMC, ppm





c
HC(w/oNMC)



is the HC concentration with sample gas bypassing the NMC, ppm





r
h



is the methane response factor as determined per paragraph 9.3.7.2.





E
M



is the methane efficiency as determined per paragraph 9.3.8.1.





E
E



is the ethane efficiency as determined per paragraph 9.3.8.2.




If r
h < 1,05, it may be omitted in equations 67, 67a and 68a.
8.6.3.   Calculation of the specific emissions
The specific emissions e
gas or e
PM (g/kWh) shall be calculated for each individual component in the following ways depending on the type of test cycle.
For the WHSC, hot WHTC, or cold WHTC, the following equation shall be applied:



 (69)
where:







m



is the mass emission of the component, g/test





W
act



is the actual cycle work as determined according to paragraph 7.8.6, kWh




For the WHTC, the final test result shall be a weighted average from cold start test and hot start test according to the following equation:



 (70)
where:







m
cold



is the mass emission of the component on the cold start test, g/test





m
hot



is the mass emission of the component on the hot start test, g/test





W
act,cold



is the actual cycle work on the cold start test, kWh





W
act,hot



is the actual cycle work on the hot start test, kWh




If periodic regeneration in accordance with paragraph 6.6.2 applies, the regeneration adjustment factors k
r,u or k
r,d shall be multiplied with or be added to, respectively, the specific emissions result e as determined in equations 69 and 70.
9.   EQUIPMENT SPECIFICATION AND VERIFICATION
This annex does not contain details of flow, pressure, and temperature measuring equipment or systems. Instead, only the linearity requirements of such equipment or systems necessary for conducting an emissions test are given in paragraph 9.2.
9.1.   Dynamometer specification
An engine dynamometer with adequate characteristics to perform the appropriate test cycle described in paragraphs 7.2.1 and 7.2.2 shall be used.
The instrumentation for torque and speed measurement shall allow the measurement accuracy of the shaft power as needed to comply with the cycle validation criteria. Additional calculations may be necessary. The accuracy of the measuring equipment shall be such that the linearity requirements given in paragraph 9.2, table 7 are not exceeded.
9.2.   Linearity requirements
The calibration of all measuring instruments and systems shall be traceable to national (international) standards. The measuring instruments and systems shall comply with the linearity requirements given in table 7. The linearity verification according to paragraph 9.2.1 shall be performed for the gas analysers at least every 3 months or whenever a system repair or change is made that could influence calibration. For the other instruments and systems, the linearity verification shall be done as required by internal audit procedures, by the instrument manufacturer or in accordance with ISO 9000 requirements.
Table 7
Linearity requirements of instruments and measurement systems









Measurement system









Slope
a1



Standard error
SEE


Coefficient of determination
r2





Engine speed


≤ 0,05 % max


0,98 – 1,02


≤ 2 % max


≥ 0,990




Engine torque


≤ 1 % max


0,98 – 1,02


≤ 2 % max


≥ 0,990




Fuel flow


≤ 1 % max


0,98 – 1,02


≤ 2 % max


≥ 0,990




Airflow


≤ 1 % max


0,98 – 1,02


≤ 2 % max


≥ 0,990




Exhaust gas flow


≤ 1 % max


0,98 – 1,02


≤ 2 % max


≥ 0,990




Diluent flow


≤ 1 % max


0,98 – 1,02


≤ 2 % max


≥ 0,990




Diluted exhaust gas flow


≤ 1 % max


0,98 – 1,02


≤ 2 % max


≥ 0,990




Sample flow


≤ 1 % max


0,98 – 1,02


≤ 2 % max


≥ 0,990




Gas analysers


≤ 0,5 % max


0,99 – 1,01


≤ 1 % max


≥ 0,998




Gas dividers


≤ 0,5 % max


0,98 – 1,02


≤ 2 % max


≥ 0,990




Temperatures


≤ 1 % max


0,99 – 1,01


≤ 1 % max


≥ 0,998




Pressures


≤ 1 % max


0,99 – 1,01


≤ 1 % max


≥ 0,998




PM balance


≤ 1 % max


0,99 – 1,01


≤ 1 % max


≥ 0,998




9.2.1.   Linearity verification
9.2.1.1.   Introduction
A linearity verification shall be performed for each measurement system listed in table 7. At least 10 reference values, or as specified otherwise, shall be introduced to the measurement system, and the measured values shall be compared to the reference values by using a least squares linear regression in accordance with equation 11. The maximum limits in table 6 refer to the maximum values expected during testing.
9.2.1.2.   General requirements
The measurement systems shall be warmed up according to the recommendations of the instrument manufacturer. The measurement systems shall be operated at their specified temperatures, pressures and flows.
9.2.1.3.   Procedure
The linearity verification shall be run for each normally used operating range with the following steps:






(a)


The instrument shall be set at zero by introducing a zero signal. For gas analysers, purified synthetic air (or nitrogen) shall be introduced directly to the analyser port.










(b)


The instrument shall be spanned by introducing a span signal. For gas analysers, an appropriate span gas shall be introduced directly to the analyser port.










(c)


The zero procedure of (a) shall be repeated.










(d)


The verification shall be established by introducing at least 10 reference values (including zero) that are within the range from zero to the highest values expected during emission testing. For gas analysers, known gas concentrations in accordance with paragraph 9.3.3.2 shall be introduced directly to the analyser port.










(e)


At a recording frequency of at least 1 Hz, the reference values shall be measured and the measured values recorded for 30 s.










(f)


The arithmetic mean values over the 30 s period shall be used to calculate the least squares linear regression parameters according to equation 11 in paragraph 7.8.7.










(g)


The linear regression parameters shall meet the requirements of paragraph 9.2, table 7.










(h)


The zero setting shall be rechecked and the verification procedure repeated, if necessary.




9.3.   Gaseous emissions measurement and sampling system
9.3.1.   Analyser specifications
9.3.1.1.   General
The analysers shall have a measuring range and response time appropriate for the accuracy required to measure the concentrations of the exhaust gas components under transient and steady state conditions.
The electromagnetic compatibility (EMC) of the equipment shall be on a level as to minimise additional errors.
9.3.1.2.   Accuracy
The accuracy, defined as the deviation of the analyser reading from the reference value, shall not exceed ±2 per cent of the reading or ±0,3 per cent of full scale whichever is larger.
9.3.1.3.   Precision
The precision, defined as 2,5 times the standard deviation of 10 repetitive responses to a given calibration or span gas, shall be no greater than 1 per cent of full scale concentration for each range used above 155 ppm (or ppm C) or 2 per cent of each range used below 155 ppm (or ppm C).
9.3.1.4.   Noise
The analyser peak-to-peak response to zero and calibration or span gases over any 10 seconds period shall not exceed 2 per cent of full scale on all ranges used.
9.3.1.5.   Zero drift
The drift of the zero response shall be specified by the instrument manufacturer.
9.3.1.6.   Span drift
The drift of the span response shall be specified by the instrument manufacturer.
9.3.1.7.   Rise time
The rise time of the analyser installed in the measurement system shall not exceed 2,5 s.
9.3.1.8.   Gas drying
Exhaust gases may be measured wet or dry. A gas-drying device, if used, shall have a minimal effect on the composition of the measured gases. Chemical dryers are not an acceptable method of removing water from the sample.
9.3.2.   Gas analysers
9.3.2.1.   Introduction
Paragraphs 9.3.2.2 to 9.3.2.7 describe the measurement principles to be used. A detailed description of the measurement systems is given in Appendix 3. The gases to be measured shall be analysed with the following instruments. For non-linear analysers, the use of linearising circuits is permitted.
9.3.2.2.   Carbon monoxide (CO) analysis
The carbon monoxide analyser shall be of the non-dispersive infrared (NDIR) absorption type.
9.3.2.3.   Carbon dioxide (CO2) analysis
The carbon dioxide analyser shall be of the non-dispersive infrared (NDIR) absorption type.
9.3.2.4.   Hydrocarbon (HC) analysis
The hydrocarbon analyser shall be of the heated flame ionisation detector (HFID) type with detector, valves, pipework, etc. heated so as to maintain a gas temperature of 463 K ± 10 K (190 ± 10 °C). Optionally, for NG fuelled and PI engines, the hydrocarbon analyser may be of the non-heated flame ionisation detector (FID) type depending upon the method used (see Appendix 3, paragraph A.3.1.3).
9.3.2.5.   Methane (CH4) and non-methane hydrocarbon (NMHC) analysis
The determination of the methane and non-methane hydrocarbon fraction shall be performed with a heated non-methane cutter (NMC) and two FID’s as per Appendix 3, paragraph A.3.1.4 and paragraph A.3.1.5. The concentration of the components shall be determined as per paragraph 8.6.2.
9.3.2.6.   Oxides of nitrogen (NOx) analysis
Two measurement instruments are specified for NOx measurement and either instrument may be used provided it meets the criteria specified in paragraphs 9.3.2.6.1 or 9.3.2.6.2, respectively. For the determination of system equivalency of an alternate measurement procedure in accordance with paragraph 5.1.1, only the CLD is permitted.
9.3.2.6.1.   Chemiluminescent detector (CLD)
If measured on a dry basis, 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 wet basis, a HCLD with converter maintained above 328 K (55 °C) shall be used, provided the water quench check (see paragraph 9.3.9.2.2) 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 analyser for wet measurement.
9.3.2.6.2.   Non-dispersive ultraviolet detector (NDUV)
A non-dispersive ultraviolet (NDUV) analyser shall be used to measure NOx concentration. If the NDUV analyser measures only NO, a NO2/NO converter shall be placed upstream of the NDUV analyser. The NDUV temperature shall be maintained to prevent aqueous condensation, unless a sample dryer is installed upstream of the NO2/NO converter, if used, or upstream of the analyser.
9.3.2.7.   Air to fuel measurement
The air to fuel measurement equipment used to determine the exhaust gas flow as specified in paragraph 8.4.1.6 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:







± 3 per cent of reading


for


λ < 2




± 5 per cent of reading


for


2 ≤ λ < 5




± 10 per cent of reading


for


5 ≤ λ




To fulfill the accuracy specified above, the sensor shall be calibrated as specified by the instrument manufacturer.
9.3.3.   Gases
The shelf life of all gases shall be respected.
9.3.3.1.   Pure gases
The required purity of the gases is defined by the contamination limits given below. The following gases shall be available for operation:






(a)


For raw exhaust gas
Purified nitrogen
(Contamination ≤ 1 ppm C1, ≤ 1 ppm CO, ≤ 400 ppm CO2, ≤ 0,1 ppm NO)
Purified oxygen
(Purity > 99,5 per cent vol O2)
Hydrogen-helium mixture (FID burner fuel)
(40 ± 1 per cent hydrogen, balance helium)
(Contamination ≤ 1 ppm C1, ≤ 400 ppm CO2)
Purified synthetic air
(Contamination ≤ 1 ppm C1, ≤ 1 ppm CO, ≤ 400 ppm CO2, ≤ 0,1 ppm NO)
(Oxygen content between 18-21 per cent vol.)










(b)


For dilute exhaust gas (optionally for raw exhaust gas)
Purified nitrogen
(Contamination ≤ 0,05 ppm C1, ≤ 1 ppm CO, ≤ 10 ppm CO2, ≤ 0,02 ppm NO)
Purified oxygen
(Purity > 99,5 per cent vol O2)
Hydrogen-helium mixture (FID burner fuel)
(40 ± 1 per cent hydrogen, balance helium)
(Contamination ≤ 0,05 ppm C1, ≤ 10 ppm CO2)
Purified synthetic air
(Contamination ≤ 0,05 ppm C1, ≤ 1 ppm CO, ≤ 10 ppm CO2, ≤ 0,02 ppm NO)
(Oxygen content between 20,5 - 21,5 per cent vol.)
If gas bottles are not available, a gas purifier may be used, if contamination levels can be demonstrated.




9.3.3.2.   Calibration and span gases
Mixtures of gases having the following chemical compositions shall be available, if applicable. Other gas combinations are allowed provided the gases do not react with one another. The expiration date of the calibration gases stated by the manufacturer shall be recorded.
C3H8 and purified synthetic air (see paragraph 9.3.3.1);
CO and purified nitrogen;
NO and purified nitrogen;
NO2 and purified synthetic air;
CO2 and purified nitrogen;
CH4 and purified synthetic air;
C2H6 and purified synthetic air
The true concentration of a calibration and span gas shall be within ± 1 per cent of the nominal value, and shall be traceable to national or international standards. All concentrations of calibration gas shall be given on a volume basis (volume percent or volume ppm).
9.3.3.3.   Gas dividers
The gases used for calibration and span may also be obtained by means of gas dividers (precision blending devices), diluting with purified N2 or with purified synthetic air. The accuracy of the gas divider shall be such that the concentration of the blended calibration gases is accurate to within ± 2 per cent. This accuracy implies that primary gases used for blending shall be known to an accuracy of at least ± 1 per cent, traceable to national or international gas standards. The verification shall be performed at between 15 and 50 per cent of full scale for each calibration incorporating a gas divider. 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 span gas directly connected to the instrument. The gas divider shall be checked at the settings used and the nominal value shall be compared to the measured concentration of the instrument. This difference shall in each point be within ± 1 per cent of the nominal value.
For conducting the linearity verification according to paragraph 9.2.1, the gas divider shall be accurate to within ± 1 per cent.
9.3.3.4.   Oxygen interference check gases
Oxygen interference check gases are a blend of propane, oxygen and nitrogen. They shall contain propane with 350 ppm C ± 75 ppm C hydrocarbon. The concentration value shall be determined to calibration gas tolerances by chromatographic analysis of total hydrocarbons plus impurities or by dynamic blending. The oxygen concentrations required for positive ignition and compression ignition engine testing are listed in table 8 with the remainder being purified nitrogen.
Table 8
Oxygen interference check gases






Type of engine


O2 concentration (per cent)




Compression ignition


21 (20 to 22)




Compression and positive ignition


10 (9 to 11)




Compression and positive ignition


5 (4 to 6)




Positive ignition


0 (0 to 1)




9.3.4.   Leak check
A system leak check shall be performed. The probe shall be disconnected from the exhaust system and the end plugged. The analyser pump shall be switched on. After an initial stabilisation period all flowmeters will read approximately zero in the absence of a leak. If not, the sampling lines shall be checked and the fault corrected.
The maximum allowable leakage rate on the vacuum side shall be 0,5 per cent of the in-use flow rate for the portion of the system being checked. The analyser flows and bypass flows may be used to estimate the in-use flow rates.
Alternatively, the system may be evacuated to a pressure of at least 20 kPa vacuum (80 kPa absolute). After an initial stabilisation period the pressure increase Δp (kPa/min) in the system shall not exceed:



 (71)
where:







V
s



is the system volume, l





q

vs



is the system flow rate, l/min




Another method is the introduction of a concentration step change at the beginning of the sampling line by switching from zero to span gas. If for a correctly calibrated analyser after an adequate period of time the reading is ≤ 99 per cent compared to the introduced concentration, this points to a leakage problem that shall be corrected.
9.3.5.   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 analysers 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 s. The gases used for the test shall cause a concentration change of at least 60 per cent full scale (FS).
The concentration trace of each single gas component shall be recorded. The response time is defined to be the difference in time between the gas switching and the appropriate change of the recorded concentration. The system response time (t
90) 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 (t
0) until the response is 10 per cent of the final reading (t
10). The rise time is defined as the time between 10 per cent and 90 per cent response of the final reading (t
90 – t
10).
For time alignment of the analyser and exhaust flow signals, the transformation time is defined as the time from the change (t
0) until the response is 50 per cent of the final reading (t
50).
The system response time shall be ≤ 10 s with a rise time of ≤ 2,5 s in accordance with paragraph 9.3.1.7 for all limited components (CO, NOx, HC or NMHC) and all ranges used. When using a NMC for the measurement of NMHC, the system response time may exceed 10 s.
9.3.6.   Efficiency test of NOx converter
The efficiency of the converter used for the conversion of NO2 into NO is tested as given in paragraphs 9.3.6.1 to 9.3.6.8 (see figure 8).




Figure 8


Scheme of NO2 converter efficiency device

solenoid valve
O2
AC
Variac
Ozonator
NO/N2
to analyser
9.3.6.1.   Test setup
Using the test setup as schematically shown in figure 8 and the procedure below, the efficiency of the converter shall be tested by means of an ozonator.
9.3.6.2.   Calibration
The CLD and the HCLD shall be calibrated in the most common operating range following the manufacturer’s specifications using zero and span gas (the NO content of which shall amount to about 80 per cent of the operating range and the NO2 concentration of the gas mixture to less than 5 per cent of the NO concentration). The NOx analyser shall be in the NO mode so that the span gas does not pass through the converter. The indicated concentration has to be recorded.
9.3.6.3.   Calculation
The per cent efficiency of the converter shall be calculated as follows:



 (72)
where:







a



is the NOx concentration according to paragraph 9.3.6.6.





b



is the NOx concentration according to paragraph 9.3.6.7.





c



is the NO concentration according to paragraph 9.3.6.4.





d



is the NO concentration according to paragraph 9.3.6.5.




9.3.6.4.   Adding of oxygen
Via a T-fitting, oxygen or zero air shall be added continuously to the gas flow until the concentration indicated is about 20 per cent less than the indicated calibration concentration given in paragraph 9.3.6.2 (the analyser is in the NO mode).
The indicated concentration (c) shall be recorded. The ozonator is kept deactivated throughout the process.
9.3.6.5.   Activation of the ozonator
The ozonator shall be activated to generate enough ozone to bring the NO concentration down to about 20 per cent (minimum 10 per cent) of the calibration concentration given in paragraph 9.3.6.2. The indicated concentration (d) shall be recorded (the analyser is in the NO mode).
9.3.6.6.   NOx mode
The NO analyser shall be switched to the NOx mode so that the gas mixture (consisting of NO, NO2, O2 and N2) now passes through the converter. The indicated concentration (a) shall be recorded (the analyser is in the NOx mode).
9.3.6.7.   Deactivation of the ozonator
The ozonator is now deactivated. The mixture of gases described in paragraph 9.3.6.6 passes through the converter into the detector. The indicated concentration (b) shall be recorded (the analyser is in the NOx mode).
9.3.6.8.   NO mode
Switched to NO mode with the ozonator deactivated, the flow of oxygen or synthetic air shall be shut off. The NOx reading of the analyser shall not deviate by more than ± 5 per cent from the value measured according to paragraph 9.3.6.2 (the analyser is in the NO mode).
9.3.6.9.   Test interval
The efficiency of the converter shall be tested at least once per month.
9.3.6.10.   Efficiency requirement
The efficiency of the converter E
NOx shall not be less than 95 per cent.
If, with the analyser in the most common range, the ozonator cannot give a reduction from 80 per cent to 20 per cent according to paragraph 9.3.6.5, the highest range which will give the reduction shall be used.
9.3.7.   Adjustment of the FID
9.3.7.1.   Optimisation of the detector response
The FID shall be adjusted as specified by the instrument manufacturer. A propane in air span gas shall be used to optimise the response on the most common operating range.
With the fuel and airflow rates set at the manufacturer’s recommendations, a 350 ± 75 ppm C span gas shall be introduced to the analyser. The response at a given fuel flow shall be determined from the difference between the span gas response and the zero gas response. The fuel flow shall be incrementally adjusted above and below the manufacturer’s specification. The span and zero response at these fuel flows shall be recorded. The difference between the span and zero response shall be plotted and the fuel flow adjusted to the rich side of the curve. This is the initial flow rate setting which may need further optimisation depending on the results of the hydrocarbon response factors and the oxygen interference check according to paragraphs 9.3.7.2 and 9.3.7.3. If the oxygen interference or the hydrocarbon response factors do not meet the following specifications, the airflow shall be incrementally adjusted above and below the manufacturer’s specifications, repeating paragraphs 9.3.7.2 and 9.3.7.3 for each flow.
The optimisation may optionally be conducted using the procedures outlined in SAE paper No 770141.
9.3.7.2.   Hydrocarbon response factors
A linearity verification of the analyser shall be performed using propane in air and purified synthetic air according to paragraph 9.2.1.3.
Response factors shall be determined when introducing an analyser into service and after major service intervals. The response factor (r
h) for a particular hydrocarbon species is the ratio of the FID C1 reading to the gas concentration in the cylinder expressed by ppm C1.
The concentration of the test gas shall be at a level to give a response of approximately 80 per cent of full scale. The concentration shall be known to an accuracy of ± 2 per cent in reference to a gravimetric standard expressed in volume. In addition, the gas cylinder shall be preconditioned for 24 hours at a temperature of 298 K ± 5 K (25 °C ± 5 °C).
The test gases to be used and the relative response factor ranges are as follows:







(a)


methane and purified synthetic air


1,00 ≤ r
h ≤ 1,15




(b)


propylene and purified synthetic air


0,90 ≤ r
h ≤ 1,1




(c)


toluene and purified synthetic air


0,90 ≤ r
h ≤ 1,1




These values are relative to a r
h of 1 for propane and purified synthetic air.
9.3.7.3.   Oxygen interference check
For raw exhaust gas analysers only, the oxygen interference check shall be performed when introducing an analyser into service and after major service intervals.
A measuring range shall be chosen where the oxygen interference check gases will fall in the upper 50 per cent. The test shall be conducted with the oven temperature set as required. Oxygen interference check gas specifications are found in paragraph 9.3.3.4.






(a)


the analyser shall be set at zero;










(b)


the analyser shall be spanned with the 0 per cent oxygen blend for positive ignition engines. Compression ignition engine instruments shall be spanned with the 21 per cent oxygen blend;










(c)


the zero response shall be rechecked. If it has changed by more than 0,5 per cent of full scale, steps (a) and (b) of this paragraph shall be repeated;










(d)


the 5 per cent and 10 per cent oxygen interference check gases shall be introduced;










(e)


the zero response shall be rechecked. If it has changed by more than ± 1 per cent of full scale, the test shall be repeated;










(f)


the oxygen interference E
O2 shall be calculated for each mixture in step (d) as follows:



 (73)
with the analyser response being



 (74)
where:







c
ref,b



is the reference HC concentration in step (b), ppm C





c
ref,d



is the reference HC concentration in step (d), ppm C





c
FS,b



is the full scale HC concentration in step (b), ppm C





c
FS,d



is the full scale HC concentration in step (d), ppm C





c
m,b



is the measured HC concentration in step (b), ppm C





c
m,d



is the measured HC concentration in step (d), ppm C














(g)


The oxygen interference E
O2 shall be less than ±1,5 per cent for all required oxygen interference check gases prior to testing.










(h)


If the oxygen interference E
O2 is greater than ±1,5 per cent, corrective action may be taken by incrementally adjusting the airflow above and below the manufacturer’s specifications, the fuel flow and the sample flow.










(i)


The oxygen interference shall be repeated for each new setting.




9.3.8.   Efficiency of the non-methane cutter (NMC)
The NMC is used for the removal of the non-methane hydrocarbons from the sample gas by oxidising all hydrocarbons except methane. Ideally, the conversion for methane is 0 per cent, and for the other hydrocarbons represented by ethane is 100 per cent. For the accurate measurement of NMHC, the two efficiencies shall be determined and used for the calculation of the NMHC emission mass flow rate (see paragraph 8.5.2).
9.3.8.1.   Methane efficiency
Methane calibration gas shall be flown through the FID with and without bypassing the NMC and the two concentrations recorded. The efficiency shall be determined as follows:



 (75)
where:







c
HC(w/NMC)



is the HC concentration with CH4 flowing through the NMC, ppm C





c
HC(w/oNMC)



is the HC concentration with CH4 bypassing the NMC, ppm C




9.3.8.2.   Ethane efficiency
Ethane calibration gas shall be flown through the FID with and without bypassing the NMC and the two concentrations recorded. The efficiency shall be determined as follows:



 (76)
where:







c
HC(w/NMC)



is the HC concentration with C2H6 flowing through the NMC, ppm C





c
HC(w/oNMC)



is the HC concentration with C2H6 bypassing the NMC, ppm C




9.3.9.   Interference effects
Other gases than the one being analysed can interfere with the reading in several ways. Positive interference occurs in NDIR instruments where the interfering gas gives the same effect as the gas being measured, but to a lesser degree. Negative interference occurs in NDIR instruments by the interfering gas broadening the absorption band of the measured gas, and in CLD instruments by the interfering gas quenching the reaction. The interference checks in paragraphs 9.3.9.1 and 9.3.9.3 shall be performed prior to an analyser’s initial use and after major service intervals.
9.3.9.1.   CO analyser interference check
Water and CO2 can interfere with the CO analyser performance. Therefore, a CO2 span gas having a concentration of 80 to 100 per cent of full scale of the maximum operating range used during testing shall be bubbled through water at room temperature and the analyser response recorded. The analyser response shall not be more than 2 per cent of the mean CO concentration expected during testing.
Interference procedures for CO2 and H2O may also be run separately. If the CO2 and H2O levels used are higher than the maximum levels expected during testing, each observed interference value shall be scaled down by multiplying the observed interference by the ratio of the maximum expected concentration value to the actual value used during this procedure. Separate interference procedures concentrations of H2O that are lower than the maximum levels expected during testing may be run, but the observed H2O interference shall be scaled up by multiplying the observed interference by the ratio of the maximum expected H2O concentration value to the actual value used during this procedure. The sum of the two scaled interference values shall meet the tolerance specified in this paragraph.
9.3.9.2.   NOx analyser quench checks for CLD analyser
The two gases of concern for CLD (and HCLD) analysers are CO2 and water vapour. Quench responses to these gases are proportional to their concentrations, and therefore require test techniques to determine the quench at the highest expected concentrations experienced during testing. If the CLD analyser uses quench compensation algorithms that utilise H2O and/or CO2 measurement instruments, quench shall be evaluated with these instruments active and with the compensation algorithms applied.
9.3.9.2.1.   CO2 quench check
A CO2 span gas having a concentration of 80 to 100 per cent of full scale of the maximum operating range shall be passed through the NDIR analyser and the CO2 value recorded as A. It shall then be diluted approximately 50 per cent with NO span gas and passed through the NDIR and CLD, with the CO2 and NO values recorded as B and C, respectively. The CO2 shall then be shut off and only the NO span gas be passed through the (H)CLD and the NO value recorded as D.
The per cent quench shall be calculated as follows:



 (77)
where:







A



is the undiluted CO2 concentration measured with NDIR, per cent





B



is the diluted CO2 concentration measured with NDIR, per cent





C



is the diluted NO concentration measured with (H)CLD, ppm





D



is the undiluted NO concentration measured with (H)CLD, ppm




Alternative methods of diluting and quantifying of CO2 and NO span gas values such as dynamic mixing/blending are permitted with the approval of the type approval authority.
9.3.9.2.2.   Water quench check
This check applies to wet gas concentration measurements only. Calculation of water quench shall consider dilution of the NO span gas with water vapour and scaling of water vapour concentration of the mixture to that expected during testing.
A NO span gas having a concentration of 80 per cent to 100 per cent of full scale of the normal operating range shall be passed through the (H) CLD and the NO value recorded as D. The NO span gas shall then be bubbled through water at room temperature and passed through the (H) CLD and the NO value recorded as C. The water temperature shall be determined and recorded as F. The mixture’s saturation vapour pressure that corresponds to the bubbler water temperature (F) shall be determined and recorded as G.
The water vapour concentration (in per cent) of the mixture shall be calculated as follows:



 (78)
and recorded as H. The expected diluted NO span gas (in water vapour) concentration shall be calculated as follows:



 (79)
and recorded as D
e. For diesel exhaust, the maximum exhaust water vapour concentration (in per cent) expected during testing shall be estimated, under the assumption of a fuel H/C ratio of 1,8/1, from the maximum CO2 concentration in the exhaust gas A as follows:



 (80)
and recorded as H
m

The per cent water quench shall be calculated as follows:



 (81)
where:







D
e



De is the expected diluted NO concentration, ppm





C



is the measured diluted NO concentration, ppm





H
m



is the maximum water vapour concentration, per cent





H



is the actual water vapour concentration, per cent




9.3.9.2.3.   Maximum allowable quench
The combined CO2 and water quench shall not exceed 2 per cent of full scale.
9.3.9.3.   NOx analyser quench check for NDUV analyser
Hydrocarbons and H2O can positively interfere with a NDUV analyser by causing a response similar to NOx. If the NDUV analyser uses compensation algorithms that utilise measurements of other gases to meet this interference verification, simultaneously such measurements shall be conducted to test the algorithms during the analyser interference verification.
9.3.9.3.1.   Procedure
The NDUV analyser shall be started, operated, zeroed, and spanned according to the instrument manufacturer’s instructions. It is recommended to extract engine exhaust to perform this verification. A CLD shall be used to quantify NOx in the exhaust. The CLD response shall be used as the reference value. Also HC shall be measured in the exhaust with a FID analyser. The FID response shall be used as the reference hydrocarbon value.
Upstream of any sample dryer, if used during testing, the engine exhaust shall be introduced into the NDUV analyser. Time shall be allowed for the analyser response to stabilise. Stabilisation time may include time to purge the transfer line and to account for analyser response. While all analysers measure the sample’s concentration, 30 s of sampled data shall be recorded, and the arithmetic means for the three analysers calculated.
The CLD mean value shall be subtracted from the NDUV mean value. This difference shall be multiplied by the ratio of the expected mean HC concentration to the HC concentration measured during the verification, as follows:



 (82)
where







c
NOx,CLD



is the measured NOx concentration with CLD, ppm





c
NOx,NDUV



is the measured NOx concentration with NDUV, ppm





c
HC,e



is the expected max. HC concentration, ppm





c
HC,e



is the measured HC concentration, ppm




9.3.9.3.2.   Maximum allowable quench
The combined HC and water quench shall not exceed 2 per cent of the NOx concentration expected during testing.
9.3.9.4.   Sample dryer
A sample dryer removes water, which can otherwise interfere with a NOx measurement.
9.3.9.4.1.   Sample dryer efficiency
For dry CLD analysers, it shall be demonstrated that for the highest expected water vapour concentration H
m (see paragraph 9.3.9.2.2), the sample dryer maintains CLD humidity at ≤ 5 g water/kg dry air (or about 0,008 per cent H2O), which is 100 per cent relative humidity at 3,9 °C and 101,3 kPa. This humidity specification is also equivalent to about 25 per cent relative humidity at 25 °C and 101,3 kPa. This may be demonstrated by measuring the temperature at the outlet of a thermal dehumidifier, or by measuring humidity at a point just upstream of the CLD. Humidity of the CLD exhaust might also be measured as long as the only flow into the CLD is the flow from the dehumidifier.
9.3.9.4.2.   Sample dryer NO2 penetration
Liquid water remaining in an improperly designed sample dryer can remove NO2 from the sample. If a sample dryer is used in combination with an NDUV analyser without an NO2/NO converter upstream, it could therefore remove NO2 from the sample prior NOx measurement.
The sample dryer shall allow for measuring at least 95 per cent of the total NO2 at the maximum expected concentration of NO2.
9.3.10.   Sampling for raw gaseous emissions, if applicable
The gaseous emissions sampling probes shall be fitted at least 0,5 m or 3 times the diameter of the exhaust pipe — whichever is the larger — upstream of the exit of the exhaust gas system but 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 “Vee” engine configuration, it is recommended to combine the manifolds upstream of the sampling probe. If this is not practical, it is permissible to acquire a sample from the group with the highest CO2 emission. For exhaust emission calculation the total exhaust mass flow shall be used.
If the engine is equipped with an exhaust after-treatment system, the exhaust sample shall be taken downstream of the exhaust after-treatment system.
9.3.11.   Sampling for dilute gaseous emissions, if applicable
The exhaust pipe between the engine and the full flow dilution system shall conform to the requirements laid down in Appendix 3. The gaseous emissions sample probe(s) shall be installed in the dilution tunnel at a point where the diluent and exhaust gas are well mixed, and in close proximity to the particulates sampling probe.
Sampling can generally be done in two ways:






(a)


the emissions are sampled into a sampling bag over the cycle and measured after completion of the test; for HC, the sample bag shall be heated to 464 ± 11 K (191 ± 11 °C), for NOx, the sample bag temperature shall be above the dew point temperature;










(b)


the emissions are sampled continuously and integrated over the cycle.




The background concentration shall be determined upstream of the dilution tunnel according to (a) or (b), and shall be subtracted from the emissions concentration according to paragraph 8.5.2.3.2.
9.4.   Particulate measurement and sampling system
9.4.1.   General specifications
To determine the mass of the particulates, a particulate dilution and sampling system, a particulate sampling filter, a microgram balance, and a temperature and humidity controlled weighing chamber, are required. The particulate sampling system shall be designed to ensure a representative sample of the particulates proportional to the exhaust flow.
9.4.2.   General requirements of the dilution system
The determination of the particulates requires dilution of the sample with filtered ambient air, synthetic air or nitrogen (the diluent). The dilution system shall be set as follows:






(a)


completely eliminate water condensation in the dilution and sampling systems;










(b)


maintain the temperature of the diluted exhaust gas between 315 K (42 °C) and 325 K (52 °C) within 20 cm upstream or downstream of the filter holder(s);










(c)


the diluent temperature shall be between 293 K and 325 K (20 °C to 52 °C) in close proximity to the entrance into the dilution tunnel;










(d)


the minimum dilution ratio shall be within the range of 5:1 to 7:1 and at least 2:1 for the primary dilution stage based on the maximum engine exhaust flow rate;










(e)


for a partial flow dilution system, the residence time in the system from the point of diluent introduction to the filter holder(s) shall be between 0,5 and 5 seconds;










(f)


for a full flow dilution system, the overall residence time in the system from the point of diluent introduction to the filter holder(s) shall be between 1 and 5 seconds, and the residence time in the secondary dilution system, if used, from the point of secondary diluent introduction to the filter holder(s) shall be at least 0,5 seconds.




Dehumidifying the diluent before entering the dilution system is permitted, and especially useful if diluent humidity is high.
9.4.3.   Particulate sampling
9.4.3.1.   Partial flow dilution system
The particulate sampling probe shall be installed in close proximity to the gaseous emissions sampling probe, but sufficiently distant as to not cause interference. Therefore, the installation provisions of paragraph 9.3.10 also apply to particulate sampling. The sampling line shall conform to the requirements laid down in Appendix 3.
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 “Vee” engine configuration, it is recommended to combine the manifolds upstream of the sampling probe. If this is not practical, it is permissible to acquire a sample from the group with the highest particulate emission. For exhaust emission calculation the total exhaust mass flow of the manifold shall be used.
9.4.3.2.   Full flow dilution system
The particulate sampling probe shall be installed in close proximity to the gaseous emissions sampling probe, but sufficiently distant as to not cause interference, in the dilution tunnel. Therefore, the installation provisions of paragraph 9.3.11 also apply to particulate sampling. The sampling line shall conform to the requirements laid down in Appendix 3.
9.4.4.   Particulate sampling filters
The diluted exhaust shall be sampled by a filter that meets the requirements of paragraphs 9.4.4.1 to 9.4.4.3 during the test sequence.
9.4.4.1.   Filter specification
All filter types shall have a 0,3 µm DOP (di-octylphthalate) collection efficiency of at least 99 per cent. The filter material shall be either:






(a)


fluorocarbon (PTFE) coated glass fibre, or










(b)


fluorocarbon (PTFE) membrane.




9.4.4.2.   Filter size
The filter shall be circular with a nominal diameter of 47 mm (tolerance of 46,50 ± 0,6 mm) and an exposed diameter (filter stain diameter) of at least 38 mm.
9.4.4.3.   Filter face velocity
The face velocity through the filter shall be between 0,90 and 1,00 m/s with less than 5 per cent of the recorded flow values exceeding this range. If the total PM mass on the filter exceeds 400 µg, the filter face velocity may be reduced to 0,50 m/s. The face velocity shall be calculated as the volumetric flow rate of the sample at the pressure upstream of the filter and temperature of the filter face, divided by the filter’s exposed area.
9.4.5.   Weighing chamber and analytical balance specifications
The chamber (or room) environment shall be free of any ambient contaminants (such as dust, aerosol, or semi-volatile material) that could contaminate the particulate filters. The weighing room shall meet the required specifications for at least 60 min before weighing filters.
9.4.5.1.   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 ± 1 K (22 °C ± 1 °C) during all filter conditioning and weighing. The humidity shall be maintained to a dew point of 282,5 K ± 1 K (9,5 °C ± 1 °C).
If the stabilisation and weighing environments are separate, the temperature of the stabilisation environment shall be maintained at a tolerance of 295 K ± 3 K (22 °C ± 3 °C), but the dew point requirement remains at 282,5 K ± 1 K (9,5 °C ± 1 °C).
Humidity and ambient temperature shall be recorded.
9.4.5.2.   Reference filter weighing
At least two unused reference filters shall be weighed within 12 hours of, but preferably at the same time as the sample filter weighing. They shall be the same material as the sample filters. Buoyancy correction shall be applied to the weighings.
If the weight of any of the reference filters changes between sample filter weighings by more than 10 µg, all sample filters shall be discarded and the emissions test repeated.
The reference filters shall be periodically replaced based on good engineering judgement, but at least once per year.
9.4.5.3.   Analytical balance
The analytical balance used to determine the filter weight shall meet the linearity verification criterion of paragraph 9.2, table 7. This implies a precision (standard deviation) of at least 2 µg and a resolution of at least 1 µg (1 digit = 1 µg).
In order to ensure accurate filter weighing, it is recommended that the balance be installed as follows:






(a)


installed on a vibration-isolation platform to isolate it from external noise and vibration;










(b)


shielded from convective airflow with a static-dissipating draft shield that is electrically grounded.




9.4.5.4.   Elimination of static electricity effects
The filter shall be neutralised prior to weighing, e.g. by a Polonium neutraliser or a device of similar effect. If a PTFE membrane filter is used, the static electricity shall be measured and is recommended to be within ±2,0 V of neutral.
Static electric charge shall be minimised in the balance environment. Possible methods are as follows:






(a)


the balance shall be electrically grounded;










(b)


stainless steel tweezers shall be used if PM samples are handled manually;










(c)


tweezers shall be grounded with a grounding strap, or a grounding strap shall be provided for the operator such that the grounding strap shares a common ground with the balance. Grounding straps shall have an appropriate resistor to protect operators from accidental shock.




9.4.5.5.   Additional specifications
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, shall be designed to minimise deposition or alteration of the particulates. All parts shall be made of electrically conductive materials that do not react with exhaust gas components, and shall be electrically grounded to prevent electrostatic effects.
9.4.5.6.   Calibration of the flow measurement instrumentation
Each flowmeter used in a particulate sampling and partial flow dilution system shall be subjected to the linearity verification, as described in paragraph 9.2.1, as often as necessary to fulfil the accuracy requirements of this gtr. For the flow reference values, an accurate flowmeter traceable to international and/or national standards shall be used. For differential flow measurement calibration see paragraph 9.4.6.2.
9.4.6.   Special requirements for the partial flow dilution system
The partial flow dilution system has to be designed to extract a proportional raw exhaust sample from the engine exhaust stream, thus responding to excursions in the exhaust stream flow rate. For this it is essential that the dilution ratio or the sampling ratio r
d or r
s be determined such that the accuracy requirements of paragraph 9.4.6.2 are fulfilled.
9.4.6.1.   System response time
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 in paragraph 9.4.6.6. If the combined transformation time of the exhaust flow measurement (see paragraph 8.3.1.2) and the partial flow system is ≤ 0,3 s, online control shall be used. If the transformation time exceeds 0,3 s, look ahead control based on a pre-recorded test run shall be used. In this case, the combined rise time shall be ≤ 1 s and the combined delay time ≤ 10 s.
The total system response shall be designed as to ensure a representative sample of the particulates, q

mp,i, proportional to the exhaust mass flow. To determine the proportionality, a regression analysis of q

mp,i versus q

mew,i shall be conducted on a minimum 5 Hz data acquisition rate, and the following criteria shall be met:






(a)


the coefficient of determination r
2 of the linear regression between q
mp,i and q

mew,i shall not be less than 0,95;










(b)


the standard error of estimate of q

mp,i on q

mew,i shall not exceed 5 per cent of q

mp maximum;










(c)



q

mp intercept of the regression line shall not exceed ± 2 per cent of q

mp maximum.




Look-ahead control is required if the combined transformation times of the particulate system, t
50,P and of the exhaust mass flow signal, t
50,F are > 0,3 s. In this case, a pre-test shall be run, and the exhaust mass flow signal of the pre-test be used for controlling the sample flow into the particulate system. A correct control of the partial dilution system is obtained, if the time trace of q

mew,pre of the pre-test, which controls q

mp, is shifted by a “look-ahead” time of t
50,P + t
50,F.
For establishing the correlation between q

mp,i and q

mew,i the data taken during the actual test shall be used, with q

mew,i time aligned by t50,F relative to q

mp,i (no contribution from t
50,P to the time alignment). That is, the time shift between q

mew and q

mp is the difference in their transformation times that were determined in paragraph 9.4.6.6.
9.4.6.2.   Specifications for differential flow measurement
For partial flow dilution systems, the accuracy of the sample flow q

mp is of special concern, if not measured directly, but determined by differential flow measurement:



 (83)
In this case, the maximum error of the difference shall be such that the accuracy of q

mp is within ± 5 per cent 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 q

mp can be obtained by either of the following methods:






(a)


the absolute accuracies of q

mdew and q

mdw are ±0,2 per cent which guarantees an accuracy of q

mp of ≤ 5 per cent at a dilution ratio of 15. However, greater errors will occur at higher dilution ratios;










(b)


calibration of q

mdw relative to q

mdew is carried out such that the same accuracies for q

mp as in (a) are obtained. For details see paragraph 9.4.6.2;










(c)


the accuracy of q

mp is determined indirectly from the accuracy of the dilution ratio as determined by a tracer gas, e.g. CO2. Accuracies equivalent to method (a) for q

mp are required;










(d)


the absolute accuracy of q

mdew and q

mdw is within ± 2 per cent of full scale, the maximum error of the difference between q

mdew and q

mdw is within 0,2 per cent, and the linearity error is within ±0,2 per cent of the highest q

mdew observed during the test.




9.4.6.3.   Calibration of differential flow measurement
The flowmeter or the flow measurement instrumentation shall be calibrated in one of the following procedures, such that the probe flow q

mp into the tunnel shall fulfil the accuracy requirements of paragraph 9.4.6.2:






(a)


The flowmeter for q

mdw shall be connected in series to the flowmeter for q

mdew, the difference between the two flowmeters shall be calibrated for at least 5 set points with flow values equally spaced between the lowest q

mdw value used during the test and the value of q

mdew used during the test. The dilution tunnel may be bypassed.










(b)


A calibrated flow device shall be connected in series to the flowmeter for q

mdew and the accuracy shall be checked for the value used for the test. The calibrated flow device shall be connected in series to the flowmeter for q

mdw, and the accuracy shall be checked for at least 5 settings corresponding to dilution ratio between 3 and 50, relative to q

mdew used during the test.










(c)


The transfer tube (TT) shall be disconnected from the exhaust, and a calibrated flow-measuring device with a suitable range to measure q

mp shall be connected to the transfer tube. q

mdew shall be set to the value used during the test, and q

mdw shall be sequentially set to at least 5 values corresponding to dilution ratios between 3 and 50. Alternatively, a special calibration flow path may be provided, in which the tunnel is bypassed, but the total and dilution airflow through the corresponding meters as in the actual test.










(d)


A tracer gas shall be fed into the exhaust 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 shall be measured. This shall be carried out for 5 dilution ratios between 3 and 50. The accuracy of the sample flow shall be determined from the dilution ratio r
d:



 (84)
The accuracies of the gas analysers shall be taken into account to guarantee the accuracy of q

mp.




9.4.6.4.   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 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 per cent or more of CO2. The partial flow sampling system shall be operated with a dilution factor of about 15 to 1.
If a carbon flow check is conducted, the procedure given in Appendix 5 shall be applied. The carbon flow rates shall be calculated according to equations 80 to 82 in Appendix 5. All carbon flow rates should agree to within 3 per cent.
9.4.6.5.   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 flowmeters shall be checked by the same method as used for calibration (see paragraph 9.4.6.2) for at least two points, including flow values of q

mdw that correspond to dilution ratios between 5 and 15 for the q

mdew value used during the test.
If it can be demonstrated by records of the calibration procedure under paragraph 9.4.6.2 that the flowmeter calibration is stable over a longer period of time, the pre-test check may be omitted.
9.4.6.6.   Determination of the transformation time
The system settings for the transformation time evaluation shall be exactly the same as during measurement 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 as to not 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 airflow if exhaust flow is calculated) input of the partial flow dilution system, from a low flow to at least 90 per cent of maximum exhaust flow. The trigger for the step change shall be the same one 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 per cent point of the flowmeter response. In a similar manner, the transformation times of the q
mp signal of the partial flow dilution system and of the q
mew,i signal of the exhaust flowmeter shall be determined. These signals are used in the regression checks performed after each test (see paragraph 9.4.6.1)
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 paragraph 9.4.6.1.
9.5.   Calibration of the CVS system
9.5.1.   General
The CVS system shall be calibrated by using an accurate flowmeter and a restricting device. The flow through the system shall be measured at different restriction settings, and the control parameters of the system shall be measured and related to the flow.
Various types of flowmeters may be used, e.g. calibrated venturi, calibrated laminar flowmeter, calibrated turbine meter.
9.5.2.   Calibration of the positive displacement pump (PDP)
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/s at pump inlet, absolute pressure and temperature) shall be plotted versus 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 per cent of the lowest flow point (highest restriction and lowest PDP speed point).
9.5.2.1.   Data analysis
The airflow rate (q

vCVS) at each restriction setting (minimum 6 settings) shall be calculated in standard m3/s from the flowmeter data using the manufacturer’s prescribed method. The airflow rate shall then be converted to pump flow (V
0) in m3/rev at absolute pump inlet temperature and pressure as follows:



 (85)
where:







q

vCVS



is the airflow rate at standard conditions (101,3 kPa, 273 K), m3/s





T



is the temperature at pump inlet, K





p
p



is the absolute pressure at pump inlet, kPa





n



is the pump speed, rev/s




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



 (86)
where:







Δp
p



is the pressure differential from pump inlet to pump outlet, kPa





p
p



is the absolute outlet pressure at pump outlet, kPa




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



 (87)

D
0 and m are the intercept and slope, 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 (D
0) shall increase as the pump flow range decreases.
The calculated values from the equation shall be within ±0,5 per cent of the measured value of V
0. 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 indicates a change of the slip rate.
9.5.3.   Calibration of the critical flow venturi (CFV)
Calibration of the CFV is based upon the flow equation for a critical venturi. Gas flow is a function of venturi inlet pressure and temperature.
To determine the range of critical flow, K
v shall be plotted as a function of venturi inlet pressure. For critical (choked) flow, K
v will have a relatively constant value. As pressure decreases (vacuum increases), the venturi becomes unchoked and K
v decreases, which indicates that the CFV is operated outside the permissible range.
9.5.3.1.   Data analysis
The airflow rate (q

vCVS) at each restriction setting (minimum 8 settings) shall be calculated in standard m3/s 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:



 (88)
where:







q

vCVS



is the airflow rate at standard conditions (101,3 kPa, 273 K), m3/s





T



is the temperature at the venturi inlet, K





p
p



is the absolute pressure at venturi inlet, kPa




The average K
V and the standard deviation shall be calculated. The standard deviation shall not exceed ±0,3 per cent of the average K
V.
9.5.4.   Calibration of the subsonic venturi (SSV)
Calibration of the SSV is based upon the flow equation for a subsonic venturi. Gas flow is a function of inlet pressure and temperature, pressure drop between the SSV inlet and throat, as shown in equation 43 (see paragraph 8.5.1.4).
9.5.4.1.   Data analysis
The airflow rate (Q
SSV) at each restriction setting (minimum 16 settings) shall be calculated in standard m3/s 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:



 (89)
where:







Q
SSV



is the airflow rate at standard conditions (101,3 kPa, 273 K), m3/s





T



is the temperature at the venturi inlet, K





d
V



is the diameter of the SSV throat, m





r
p



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








r
D



is the ratio of the SSV throat diameter, d
V, to the inlet pipe inner diameter D





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



 (90)
with



 (91)
where:






A1



is 25,55152 in SI units of 








Q
SSV



is the airflow rate at standard conditions (101,3 kPa, 273 K), m3/s





d
V



is the diameter of the SSV throat, m





μ



is the absolute or dynamic viscosity of the gas, kg/ms




b


is 1,458 × 106 (empirical constant), kg/ms K0,5





S


is 110,4 (empirical constant), K




Because Q
SSV is an input to the Re equation, the calculations shall be started with an initial guess for Q
SSV or C
d of the calibration venturi, and repeated until Q
SSV converges. The convergence method shall be accurate to 0,1 per cent of point or better.
For a minimum of sixteen points in the region of subsonic flow, the calculated values of C
d from the resulting calibration curve fit equation shall be within ±0,5 per cent of the measured C
d for each calibration point.
9.5.5.   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 paragraph 8.5.2.4 except in the case of propane where a u factor of 0,000472 is used in place of 0,000480 for HC. Either of the following two techniques shall be used.
9.5.5.1.   Metering with a critical flow orifice
A known quantity of pure gas (carbon monoxide or 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 per cent of the known mass of the gas injected.
9.5.5.2.   Metering by means of a gravimetric technique
The mass of a small cylinder filled with carbon monoxide or 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 per cent of the known mass of the gas injected.




‘APPENDIX 1
WHTC ENGINE DYNAMOMETER SCHEDULE







Time


Norm. speed


Norm. torque




s


per cent


per cent




1


0,0


0,0




2


0,0


0,0




3


0,0


0,0




4


0,0


0,0




5


0,0


0,0




6


0,0


0,0




7


1,5


8,9




8


15,8


30,9




9


27,4


1,3




10


32,6


0,7




11


34,8


1,2




12


36,2


7,4




13


37,1


6,2




14


37,9


10,2




15


39,6


12,3




16


42,3


12,5




17


45,3


12,6




18


48,6


6,0




19


40,8


0,0




20


33,0


16,3




21


42,5


27,4




22


49,3


26,7




23


54,0


18,0




24


57,1


12,9




25


58,9


8,6




26


59,3


6,0




27


59,0


4,9




28


57,9


m




29


55,7


m




30


52,1


m




31


46,4


m




32


38,6


m




33


29,0


m




34


20,8


m




35


16,9


m




36


16,9


42,5




37


18,8


38,4




38


20,7


32,9




39


21,0


0,0




40


19,1


0,0




41


13,7


0,0




42


2,2


0,0




43


0,0


0,0




44


0,0


0,0




45


0,0


0,0




46


0,0


0,0




47


0,0


0,0




48


0,0


0,0




49


0,0


0,0




50


0,0


13,1




51


13,1


30,1




52


26,3


25,5




53


35,0


32,2




54


41,7


14,3




55


42,2


0,0




56


42,8


11,6




57


51,0


20,9




58


60,0


9,6




59


49,4


0,0




60


38,9


16,6




61


43,4


30,8




62


49,4


14,2




63


40,5


0,0




64


31,5


43,5




65


36,6


78,2




66


40,8


67,6




67


44,7


59,1




68


48,3


52,0




69


51,9


63,8




70


54,7


27,9




71


55,3


18,3




72


55,1


16,3




73


54,8


11,1




74


54,7


11,5




75


54,8


17,5




76


55,6


18,0




77


57,0


14,1




78


58,1


7,0




79


43,3


0,0




80


28,5


25,0




81


30,4


47,8




82


32,1


39,2




83


32,7


39,3




84


32,4


17,3




85


31,6


11,4




86


31,1


10,2




87


31,1


19,5




88


31,4


22,5




89


31,6


22,9




90


31,6


24,3




91


31,9


26,9




92


32,4


30,6




93


32,8


32,7




94


33,7


32,5




95


34,4


29,5




96


34,3


26,5




97


34,4


24,7




98


35,0


24,9




99


35,6


25,2




100


36,1


24,8




101


36,3


24,0




102


36,2


23,6




103


36,2


23,5




104


36,8


22,7




105


37,2


20,9




106


37,0


19,2




107


36,3


18,4




108


35,4


17,6




109


35,2


14,9




110


35,4


9,9




111


35,5


4,3




112


35,2


6,6




113


34,9


10,0




114


34,7


25,1




115


34,4


29,3




116


34,5


20,7




117


35,2


16,6




118


35,8


16,2




119


35,6


20,3




120


35,3


22,5




121


35,3


23,4




122


34,7


11,9




123


45,5


0,0




124


56,3


m




125


46,2


m




126


50,1


0,0




127


54,0


m




128


40,5


m




129


27,0


m




130


13,5


m




131


0,0


0,0




132


0,0


0,0




133


0,0


0,0




134


0,0


0,0




135


0,0


0,0




136


0,0


0,0




137


0,0


0,0




138


0,0


0,0




139


0,0


0,0




140


0,0


0,0




141


0,0


0,0




142


0,0


4,9




143


0,0


7,3




144


4,4


28,7




145


11,1


26,4




146


15,0


9,4




147


15,9


0,0




148


15,3


0,0




149


14,2


0,0




150


13,2


0,0




151


11,6


0,0




152


8,4


0,0




153


5,4


0,0




154


4,3


5,6




155


5,8


24,4




156


9,7


20,7




157


13,6


21,1




158


15,6


21,5




159


16,5


21,9




160


18,0


22,3




161


21,1


46,9




162


25,2


33,6




163


28,1


16,6




164


28,8


7,0




165


27,5


5,0




166


23,1


3,0




167


16,9


1,9




168


12,2


2,6




169


9,9


3,2




170


9,1


4,0




171


8,8


3,8




172


8,5


12,2




173


8,2


29,4




174


9,6


20,1




175


14,7


16,3




176


24,5


8,7




177


39,4


3,3




178


39,0


2,9




179


38,5


5,9




180


42,4


8,0




181


38,2


6,0




182


41,4


3,8




183


44,6


5,4




184


38,8


8,2




185


37,5


8,9




186


35,4


7,3




187


28,4


7,0




188


14,8


7,0




189


0,0


5,9




190


0,0


0,0




191


0,0


0,0




192


0,0


0,0




193


0,0


0,0




194


0,0


0,0




195


0,0


0,0




196


0,0


0,0




197


0,0


0,0




198


0,0


0,0




199


0,0


0,0




200


0,0


0,0




201


0,0


0,0




202


0,0


0,0




203


0,0


0,0




204


0,0


0,0




205


0,0


0,0




206


0,0


0,0




207


0,0


0,0




208


0,0


0,0




209


0,0


0,0




210


0,0


0,0




211


0,0


0,0




212


0,0


0,0




213


0,0


0,0




214


0,0


0,0




215


0,0


0,0




216


0,0


0,0




217


0,0


0,0




218


0,0


0,0




219


0,0


0,0




220


0,0


0,0




221


0,0


0,0




222


0,0


0,0




223


0,0


0,0




224


0,0


0,0




225


0,0


0,0




226


0,0


0,0




227


0,0


0,0




228


0,0


0,0




229


0,0


0,0




230


0,0


0,0




231


0,0


0,0




232


0,0


0,0




233


0,0


0,0




234


0,0


0,0




235


0,0


0,0




236


0,0


0,0




237


0,0


0,0




238


0,0


0,0




239


0,0


0,0




240


0,0


0,0




241


0,0


0,0




242


0,0


0,0




243


0,0


0,0




244


0,0


0,0




245


0,0


0,0




246


0,0


0,0




247


0,0


0,0




248


0,0


0,0




249


0,0


0,0




250


0,0


0,0




251


0,0


0,0




252


0,0


0,0




253


0,0


31,6




254


9,4


13,6




255


22,2


16,9




256


33,0


53,5




257


43,7


22,1




258


39,8


0,0




259


36,0


45,7




260


47,6


75,9




261


61,2


70,4




262


72,3


70,4




263


76,0


m




264


74,3


m




265


68,5


m




266


61,0


m




267


56,0


m




268


54,0


m




269


53,0


m




270


50,8


m




271


46,8


m




272


41,7


m




273


35,9


m




274


29,2


m




275


20,7


m




276


10,1


m




277


0,0


m




278


0,0


0,0




279


0,0


0,0




280


0,0


0,0




281


0,0


0,0




282


0,0


0,0




283


0,0


0,0




284


0,0


0,0




285


0,0


0,0




286


0,0


0,0




287


0,0


0,0




288


0,0


0,0




289


0,0


0,0




290


0,0


0,0




291


0,0


0,0




292


0,0


0,0




293


0,0


0,0




294


0,0


0,0




295


0,0


0,0




296


0,0


0,0




297


0,0


0,0




298


0,0


0,0




299


0,0


0,0




300


0,0


0,0




301


0,0


0,0




302


0,0


0,0




303


0,0


0,0




304


0,0


0,0




305


0,0


0,0




306


0,0


0,0




307


0,0


0,0




308


0,0


0,0




309


0,0


0,0




310


0,0


0,0




311


0,0


0,0




312


0,0


0,0




313


0,0


0,0




314


0,0


0,0




315


0,0


0,0




316


0,0


0,0




317


0,0


0,0




318


0,0


0,0




319


0,0


0,0




320


0,0


0,0




321


0,0


0,0




322


0,0


0,0




323


0,0


0,0




324


4,5


41,0




325


17,2


38,9




326


30,1


36,8




327


41,0


34,7




328


50,0


32,6




329


51,4


0,1




330


47,8


m




331


40,2


m




332


32,0


m




333


24,4


m




334


16,8


m




335


8,1


m




336


0,0


m




337


0,0


0,0




338


0,0


0,0




339


0,0


0,0




340


0,0


0,0




341


0,0


0,0




342


0,0


0,0




343


0,0


0,0




344


0,0


0,0




345


0,0


0,0




346


0,0


0,0




347


0,0


0,0




348


0,0


0,0




349


0,0


0,0




350


0,0


0,0




351


0,0


0,0




352


0,0


0,0




353


0,0


0,0




354


0,0


0,5




355


0,0


4,9




356


9,2


61,3




357


22,4


40,4




358


36,5


50,1




359


47,7


21,0




360


38,8


0,0




361


30,0


37,0




362


37,0


63,6




363


45,5


90,8




364


54,5


40,9




365


45,9


0,0




366


37,2


47,5




367


44,5


84,4




368


51,7


32,4




369


58,1


15,2




370


45,9


0,0




371


33,6


35,8




372


36,9


67,0




373


40,2


84,7




374


43,4


84,3




375


45,7


84,3




376


46,5


m




377


46,1


m




378


43,9


m




379


39,3


m




380


47,0


m




381


54,6


m




382


62,0


m




383


52,0


m




384


43,0


m




385


33,9


m




386


28,4


m




387


25,5


m




388


24,6


11,0




389


25,2


14,7




390


28,6


28,4




391


35,5


65,0




392


43,8


75,3




393


51,2


34,2




394


40,7


0,0




395


30,3


45,4




396


34,2


83,1




397


37,6


85,3




398


40,8


87,5




399


44,8


89,7




400


50,6


91,9




401


57,6


94,1




402


64,6


44,6




403


51,6


0,0




404


38,7


37,4




405


42,4


70,3




406


46,5


89,1




407


50,6


93,9




408


53,8


33,0




409


55,5


20,3




410


55,8


5,2




411


55,4


m




412


54,4


m




413


53,1


m




414


51,8


m




415


50,3


m




416


48,4


m




417


45,9


m




418


43,1


m




419


40,1


m




420


37,4


m




421


35,1


m




422


32,8


m




423


45,3


0,0




424


57,8


m




425


50,6


m




426


41,6


m




427


47,9


0,0




428


54,2


m




429


48,1


m




430


47,0


31,3




431


49,0


38,3




432


52,0


40,1




433


53,3


14,5




434


52,6


0,8




435


49,8


m




436


51,0


18,6




437


56,9


38,9




438


67,2


45,0




439


78,6


21,5




440


65,5


0,0




441


52,4


31,3




442


56,4


60,1




443


59,7


29,2




444


45,1


0,0




445


30,6


4,2




446


30,9


8,4




447


30,5


4,3




448


44,6


0,0




449


58,8


m




450


55,1


m




451


50,6


m




452


45,3


m




453


39,3


m




454


49,1


0,0




455


58,8


m




456


50,7


m




457


42,4


m




458


44,1


0,0




459


45,7


m




460


32,5


m




461


20,7


m




462


10,0


m




463


0,0


0,0




464


0,0


1,5




465


0,9


41,1




466


7,0


46,3




467


12,8


48,5




468


17,0


50,7




469


20,9


52,9




470


26,7


55,0




471


35,5


57,2




472


46,9


23,8




473


44,5


0,0




474


42,1


45,7




475


55,6


77,4




476


68,8


100,0




477


81,7


47,9




478


71,2


0,0




479


60,7


38,3




480


68,8


72,7




481


75,0


m




482


61,3


m




483


53,5


m




484


45,9


58,0




485


48,1


80,0




486


49,4


97,9




487


49,7


m




488


48,7


m




489


45,5


m




490


40,4


m




491


49,7


0,0




492


59,0


m




493


48,9


m




494


40,0


m




495


33,5


m




496


30,0


m




497


29,1


12,0




498


29,3


40,4




499


30,4


29,3




500


32,2


15,4




501


33,9


15,8




502


35,3


14,9




503


36,4


15,1




504


38,0


15,3




505


40,3


50,9




506


43,0


39,7




507


45,5


20,6




508


47,3


20,6




509


48,8


22,1




510


50,1


22,1




511


51,4


42,4




512


52,5


31,9




513


53,7


21,6




514


55,1


11,6




515


56,8


5,7




516


42,4


0,0




517


27,9


8,2




518


29,0


15,9




519


30,4


25,1




520


32,6


60,5




521


35,4


72,7




522


38,4


88,2




523


41,0


65,1




524


42,9


25,6




525


44,2


15,8




526


44,9


2,9




527


45,1


m




528


44,8


m




529


43,9


m




530


42,4


m




531


40,2


m




532


37,1


m




533


47,0


0,0




534


57,0


m




535


45,1


m




536


32,6


m




537


46,8


0,0




538


61,5


m




539


56,7


m




540


46,9


m




541


37,5


m




542


30,3


m




543


27,3


32,3




544


30,8


60,3




545


41,2


62,3




546


36,0


0,0




547


30,8


32,3




548


33,9


60,3




549


34,6


38,4




550


37,0


16,6




551


42,7


62,3




552


50,4


28,1




553


40,1


0,0




554


29,9


8,0




555


32,5


15,0




556


34,6


63,1




557


36,7


58,0




558


39,4


52,9




559


42,8


47,8




560


46,8


42,7




561


50,7


27,5




562


53,4


20,7




563


54,2


13,1




564


54,2


0,4




565


53,4


0,0




566


51,4


m




567


48,7


m




568


45,6


m




569


42,4


m




570


40,4


m




571


39,8


5,8




572


40,7


39,7




573


43,8


37,1




574


48,1


39,1




575


52,0


22,0




576


54,7


13,2




577


56,4


13,2




578


57,5


6,6




579


42,6


0,0




580


27,7


10,9




581


28,5


21,3




582


29,2


23,9




583


29,5


15,2




584


29,7


8,8




585


30,4


20,8




586


31,9


22,9




587


34,3


61,4




588


37,2


76,6




589


40,1


27,5




590


42,3


25,4




591


43,5


32,0




592


43,8


6,0




593


43,5


m




594


42,8


m




595


41,7


m




596


40,4


m




597


39,3


m




598


38,9


12,9




599


39,0


18,4




600


39,7


39,2




601


41,4


60,0




602


43,7


54,5




603


46,2


64,2




604


48,8


73,3




605


51,0


82,3




606


52,1


0,0




607


52,0


m




608


50,9


m




609


49,4


m




610


47,8


m




611


46,6


m




612


47,3


35,3




613


49,2


74,1




614


51,1


95,2




615


51,7


m




616


50,8


m




617


47,3


m




618


41,8


m




619


36,4


m




620


30,9


m




621


25,5


37,1




622


33,8


38,4




623


42,1


m




624


34,1


m




625


33,0


37,1




626


36,4


38,4




627


43,3


17,1




628


35,7


0,0




629


28,1


11,6




630


36,5


19,2




631


45,2


8,3




632


36,5


0,0




633


27,9


32,6




634


31,5


59,6




635


34,4


65,2




636


37,0


59,6




637


39,0


49,0




638


40,2


m




639


39,8


m




640


36,0


m




641


29,7


m




642


21,5


m




643


14,1


m




644


0,0


0,0




645


0,0


0,0




646


0,0


0,0




647


0,0


0,0




648


0,0


0,0




649


0,0


0,0




650


0,0


0,0




651


0,0


0,0




652


0,0


0,0




653


0,0


0,0




654


0,0


0,0




655


0,0


0,0




656


0,0


3,4




657


1,4


22,0




658


10,1


45,3




659


21,5


10,0




660


32,2


0,0




661


42,3


46,0




662


57,1


74,1




663


72,1


34,2




664


66,9


0,0




665


60,4


41,8




666


69,1


79,0




667


77,1


38,3




668


63,1


0,0




669


49,1


47,9




670


53,4


91,3




671


57,5


85,7




672


61,5


89,2




673


65,5


85,9




674


69,5


89,5




675


73,1


75,5




676


76,2


73,6




677


79,1


75,6




678


81,8


78,2




679


84,1


39,0




680


69,6


0,0




681


55,0


25,2




682


55,8


49,9




683


56,7


46,4




684


57,6


76,3




685


58,4


92,7




686


59,3


99,9




687


60,1


95,0




688


61,0


46,7




689


46,6


0,0




690


32,3


34,6




691


32,7


68,6




692


32,6


67,0




693


31,3


m




694


28,1


m




695


43,0


0,0




696


58,0


m




697


58,9


m




698


49,4


m




699


41,5


m




700


48,4


0,0




701


55,3


m




702


41,8


m




703


31,6


m




704


24,6


m




705


15,2


m




706


7,0


m




707


0,0


0,0




708


0,0


0,0




709


0,0


0,0




710


0,0


0,0




711


0,0


0,0




712


0,0


0,0




713


0,0


0,0




714


0,0


0,0




715


0,0


0,0




716


0,0


0,0




717


0,0


0,0




718


0,0


0,0




719


0,0


0,0




720


0,0


0,0




721


0,0


0,0




722


0,0


0,0




723


0,0


0,0




724


0,0


0,0




725


0,0


0,0




726


0,0


0,0




727


0,0


0,0




728


0,0


0,0




729


0,0


0,0




730


0,0


0,0




731


0,0


0,0




732


0,0


0,0




733


0,0


0,0




734


0,0


0,0




735


0,0


0,0




736


0,0


0,0




737


0,0


0,0




738


0,0


0,0




739


0,0


0,0




740


0,0


0,0




741


0,0


0,0




742


0,0


0,0




743


0,0


0,0




744


0,0


0,0




745


0,0


0,0




746


0,0


0,0




747


0,0


0,0




748


0,0


0,0




749


0,0


0,0




750


0,0


0,0




751


0,0


0,0




752


0,0


0,0




753


0,0


0,0




754


0,0


0,0




755


0,0


0,0




756


0,0


0,0




757


0,0


0,0




758


0,0


0,0




759


0,0


0,0




760


0,0


0,0




761


0,0


0,0




762


0,0


0,0




763


0,0


0,0




764


0,0


0,0




765


0,0


0,0




766


0,0


0,0




767


0,0


0,0




768


0,0


0,0




769


0,0


0,0




770


0,0


0,0




771


0,0


22,0




772


4,5


25,8




773


15,5


42,8




774


30,5


46,8




775


45,5


29,3




776


49,2


13,6




777


39,5


0,0




778


29,7


15,1




779


34,8


26,9




780


40,0


13,6




781


42,2


m




782


42,1


m




783


40,8


m




784


37,7


37,6




785


47,0


35,0




786


48,8


33,4




787


41,7


m




788


27,7


m




789


17,2


m




790


14,0


37,6




791


18,4


25,0




792


27,6


17,7




793


39,8


6,8




794


34,3


0,0




795


28,7


26,5




796


41,5


40,9




797


53,7


17,5




798


42,4


0,0




799


31,2


27,3




800


32,3


53,2




801


34,5


60,6




802


37,6


68,0




803


41,2


75,4




804


45,8


82,8




805


52,3


38,2




806


42,5


0,0




807


32,6


30,5




808


35,0


57,9




809


36,0


77,3




810


37,1


96,8




811


39,6


80,8




812


43,4


78,3




813


47,2


73,4




814


49,6


66,9




815


50,2


62,0




816


50,2


57,7




817


50,6


62,1




818


52,3


62,9




819


54,8


37,5




820


57,0


18,3




821


42,3


0,0




822


27,6


29,1




823


28,4


57,0




824


29,1


51,8




825


29,6


35,3




826


29,7


33,3




827


29,8


17,7




828


29,5


m




829


28,9


m




830


43,0


0,0




831


57,1


m




832


57,7


m




833


56,0


m




834


53,8


m




835


51,2


m




836


48,1


m




837


44,5


m




838


40,9


m




839


38,1


m




840


37,2


42,7




841


37,5


70,8




842


39,1


48,6




843


41,3


0,1




844


42,3


m




845


42,0


m




846


40,8


m




847


38,6


m




848


35,5


m




849


32,1


m




850


29,6


m




851


28,8


39,9




852


29,2


52,9




853


30,9


76,1




854


34,3


76,5




855


38,3


75,5




856


42,5


74,8




857


46,6


74,2




858


50,7


76,2




859


54,8


75,1




860


58,7


36,3




861


45,2


0,0




862


31,8


37,2




863


33,8


71,2




864


35,5


46,4




865


36,6


33,6




866


37,2


20,0




867


37,2


m




868


37,0


m




869


36,6


m




870


36,0


m




871


35,4


m




872


34,7


m




873


34,1


m




874


33,6


m




875


33,3


m




876


33,1


m




877


32,7


m




878


31,4


m




879


45,0


0,0




880


58,5


m




881


53,7


m




882


47,5


m




883


40,6


m




884


34,1


m




885


45,3


0,0




886


56,4


m




887


51,0


m




888


44,5


m




889


36,4


m




890


26,6


m




891


20,0


m




892


13,3


m




893


6,7


m




894


0,0


0,0




895


0,0


0,0




896


0,0


0,0




897


0,0


0,0




898


0,0


0,0




899


0,0


0,0




900


0,0


0,0




901


0,0


5,8




902


2,5


27,9




903


12,4


29,0




904


19,4


30,1




905


29,3


31,2




906


37,1


10,4




907


40,6


4,9




908


35,8


0,0




909


30,9


7,6




910


35,4


13,8




911


36,5


11,1




912


40,8


48,5




913


49,8


3,7




914


41,2


0,0




915


32,7


29,7




916


39,4


52,1




917


48,8


22,7




918


41,6


0,0




919


34,5


46,6




920


39,7


84,4




921


44,7


83,2




922


49,5


78,9




923


52,3


83,8




924


53,4


77,7




925


52,1


69,6




926


47,9


63,6




927


46,4


55,2




928


46,5


53,6




929


46,4


62,3




930


46,1


58,2




931


46,2


61,8




932


47,3


62,3




933


49,3


57,1




934


52,6


58,1




935


56,3


56,0




936


59,9


27,2




937


45,8


0,0




938


31,8


28,8




939


32,7


56,5




940


33,4


62,8




941


34,6


68,2




942


35,8


68,6




943


38,6


65,0




944


42,3


61,9




945


44,1


65,3




946


45,3


63,2




947


46,5


30,6




948


46,7


11,1




949


45,9


16,1




950


45,6


21,8




951


45,9


24,2




952


46,5


24,7




953


46,7


24,7




954


46,8


28,2




955


47,2


31,2




956


47,6


29,6




957


48,2


31,2




958


48,6


33,5




959


48,8


m




960


47,6


m




961


46,3


m




962


45,2


m




963


43,5


m




964


41,4


m




965


40,3


m




966


39,4


m




967


38,0


m




968


36,3


m




969


35,3


5,8




970


35,4


30,2




971


36,6


55,6




972


38,6


48,5




973


39,9


41,8




974


40,3


38,2




975


40,8


35,0




976


41,9


32,4




977


43,2


26,4




978


43,5


m




979


42,9


m




980


41,5


m




981


40,9


m




982


40,5


m




983


39,5


m




984


38,3


m




985


36,9


m




986


35,4


m




987


34,5


m




988


33,9


m




989


32,6


m




990


30,9


m




991


29,9


m




992


29,2


m




993


44,1


0,0




994


59,1


m




995


56,8


m




996


53,5


m




997


47,8


m




998


41,9


m




999


35,9


m




1000


44,3


0,0




1001


52,6


m




1002


43,4


m




1003


50,6


0,0




1004


57,8


m




1005


51,6


m




1006


44,8


m




1007


48,6


0,0




1008


52,4


m




1009


45,4


m




1010


37,2


m




1011


26,3


m




1012


17,9


m




1013


16,2


1,9




1014


17,8


7,5




1015


25,2


18,0




1016


39,7


6,5




1017


38,6


0,0




1018


37,4


5,4




1019


43,4


9,7




1020


46,9


15,7




1021


52,5


13,1




1022


56,2


6,3




1023


44,0


0,0




1024


31,8


20,9




1025


38,7


36,3




1026


47,7


47,5




1027


54,5


22,0




1028


41,3


0,0




1029


28,1


26,8




1030


31,6


49,2




1031


34,5


39,5




1032


36,4


24,0




1033


36,7


m




1034


35,5


m




1035


33,8


m




1036


33,7


19,8




1037


35,3


35,1




1038


38,0


33,9




1039


40,1


34,5




1040


42,2


40,4




1041


45,2


44,0




1042


48,3


35,9




1043


50,1


29,6




1044


52,3


38,5




1045


55,3


57,7




1046


57,0


50,7




1047


57,7


25,2




1048


42,9


0,0




1049


28,2


15,7




1050


29,2


30,5




1051


31,1


52,6




1052


33,4


60,7




1053


35,0


61,4




1054


35,3


18,2




1055


35,2


14,9




1056


34,9


11,7




1057


34,5


12,9




1058


34,1


15,5




1059


33,5


m




1060


31,8


m




1061


30,1


m




1062


29,6


10,3




1063


30,0


26,5




1064


31,0


18,8




1065


31,5


26,5




1066


31,7


m




1067


31,5


m




1068


30,6


m




1069


30,0


m




1070


30,0


m




1071


29,4


m




1072


44,3


0,0




1073


59,2


m




1074


58,3


m




1075


57,1


m




1076


55,4


m




1077


53,5


m




1078


51,5


m




1079


49,7


m




1080


47,9


m




1081


46,4


m




1082


45,5


m




1083


45,2


m




1084


44,3


m




1085


43,6


m




1086


43,1


m




1087


42,5


25,6




1088


43,3


25,7




1089


46,3


24,0




1090


47,8


20,6




1091


47,2


3,8




1092


45,6


4,4




1093


44,6


4,1




1094


44,1


m




1095


42,9


m




1096


40,9


m




1097


39,2


m




1098


37,0


m




1099


35,1


2,0




1100


35,6


43,3




1101


38,7


47,6




1102


41,3


40,4




1103


42,6


45,7




1104


43,9


43,3




1105


46,9


41,2




1106


52,4


40,1




1107


56,3


39,3




1108


57,4


25,5




1109


57,2


25,4




1110


57,0


25,4




1111


56,8


25,3




1112


56,3


25,3




1113


55,6


25,2




1114


56,2


25,2




1115


58,0


12,4




1116


43,4


0,0




1117


28,8


26,2




1118


30,9


49,9




1119


32,3


40,5




1120


32,5


12,4




1121


32,4


12,2




1122


32,1


6,4




1123


31,0


12,4




1124


30,1


18,5




1125


30,4


35,6




1126


31,2


30,1




1127


31,5


30,8




1128


31,5


26,9




1129


31,7


33,9




1130


32,0


29,9




1131


32,1


m




1132


31,4


m




1133


30,3


m




1134


29,8


m




1135


44,3


0,0




1136


58,9


m




1137


52,1


m




1138


44,1


m




1139


51,7


0,0




1140


59,2


m




1141


47,2


m




1142


35,1


0,0




1143


23,1


m




1144


13,1


m




1145


5,0


m




1146


0,0


0,0




1147


0,0


0,0




1148


0,0


0,0




1149


0,0


0,0




1150


0,0


0,0




1151


0,0


0,0




1152


0,0


0,0




1153


0,0


0,0




1154


0,0


0,0




1155


0,0


0,0




1156


0,0


0,0




1157


0,0


0,0




1158


0,0


0,0




1159


0,0


0,0




1160


0,0


0,0




1161


0,0


0,0




1162


0,0


0,0




1163


0,0


0,0




1164


0,0


0,0




1165


0,0


0,0




1166


0,0


0,0




1167


0,0


0,0




1168


0,0


0,0




1169


0,0


0,0




1170


0,0


0,0




1171


0,0


0,0




1172


0,0


0,0




1173


0,0


0,0




1174


0,0


0,0




1175


0,0


0,0




1176


0,0


0,0




1177


0,0


0,0




1178


0,0


0,0




1179


0,0


0,0




1180


0,0


0,0




1181


0,0


0,0




1182


0,0


0,0




1183


0,0


0,0




1184


0,0


0,0




1185


0,0


0,0




1186


0,0


0,0




1187


0,0


0,0




1188


0,0


0,0




1189


0,0


0,0




1190


0,0


0,0




1191


0,0


0,0




1192


0,0


0,0




1193


0,0


0,0




1194


0,0


0,0




1195


0,0


0,0




1196


0,0


20,4




1197


12,6


41,2




1198


27,3


20,4




1199


40,4


7,6




1200


46,1


m




1201


44,6


m




1202


42,7


14,7




1203


42,9


7,3




1204


36,1


0,0




1205


29,3


15,0




1206


43,8


22,6




1207


54,9


9,9




1208


44,9


0,0




1209


34,9


47,4




1210


42,7


82,7




1211


52,0


81,2




1212


61,8


82,7




1213


71,3


39,1




1214


58,1


0,0




1215


44,9


42,5




1216


46,3


83,3




1217


46,8


74,1




1218


48,1


75,7




1219


50,5


75,8




1220


53,6


76,7




1221


56,9


77,1




1222


60,2


78,7




1223


63,7


78,0




1224


67,2


79,6




1225


70,7


80,9




1226


74,1


81,1




1227


77,5


83,6




1228


80,8


85,6




1229


84,1


81,6




1230


87,4


88,3




1231


90,5


91,9




1232


93,5


94,1




1233


96,8


96,6




1234


100,0


m




1235


96,0


m




1236


81,9


m




1237


68,1


m




1238


58,1


84,7




1239


58,5


85,4




1240


59,5


85,6




1241


61,0


86,6




1242


62,6


86,8




1243


64,1


87,6




1244


65,4


87,5




1245


66,7


87,8




1246


68,1


43,5




1247


55,2


0,0




1248


42,3


37,2




1249


43,0


73,6




1250


43,5


65,1




1251


43,8


53,1




1252


43,9


54,6




1253


43,9


41,2




1254


43,8


34,8




1255


43,6


30,3




1256


43,3


21,9




1257


42,8


19,9




1258


42,3


m




1259


41,4


m




1260


40,2


m




1261


38,7


m




1262


37,1


m




1263


35,6


m




1264


34,2


m




1265


32,9


m




1266


31,8


m




1267


30,7


m




1268


29,6


m




1269


40,4


0,0




1270


51,2


m




1271


49,6


m




1272


48,0


m




1273


46,4


m




1274


45,0


m




1275


43,6


m




1276


42,3


m




1277


41,0


m




1278


39,6


m




1279


38,3


m




1280


37,1


m




1281


35,9


m




1282


34,6


m




1283


33,0


m




1284


31,1


m




1285


29,2


m




1286


43,3


0,0




1287


57,4


32,8




1288


59,9


65,4




1289


61,9


76,1




1290


65,6


73,7




1291


69,9


79,3




1292


74,1


81,3




1293


78,3


83,2




1294


82,6


86,0




1295


87,0


89,5




1296


91,2


90,8




1297


95,3


45,9




1298


81,0


0,0




1299


66,6


38,2




1300


67,9


75,5




1301


68,4


80,5




1302


69,0


85,5




1303


70,0


85,2




1304


71,6


85,9




1305


73,3


86,2




1306


74,8


86,5




1307


76,3


42,9




1308


63,3


0,0




1309


50,4


21,2




1310


50,6


42,3




1311


50,6


53,7




1312


50,4


90,1




1313


50,5


97,1




1314


51,0


100,0




1315


51,9


100,0




1316


52,6


100,0




1317


52,8


32,4




1318


47,7


0,0




1319


42,6


27,4




1320


42,1


53,5




1321


41,8


44,5




1322


41,4


41,1




1323


41,0


21,0




1324


40,3


0,0




1325


39,3


1,0




1326


38,3


15,2




1327


37,6


57,8




1328


37,3


73,2




1329


37,3


59,8




1330


37,4


52,2




1331


37,4


16,9




1332


37,1


34,3




1333


36,7


51,9




1334


36,2


25,3




1335


35,6


m




1336


34,6


m




1337


33,2


m




1338


31,6


m




1339


30,1


m




1340


28,8


m




1341


28,0


29,5




1342


28,6


100,0




1343


28,8


97,3




1344


28,8


73,4




1345


29,6


56,9




1346


30,3


91,7




1347


31,0


90,5




1348


31,8


81,7




1349


32,6


79,5




1350


33,5


86,9




1351


34,6


100,0




1352


35,6


78,7




1353


36,4


50,5




1354


37,0


57,0




1355


37,3


69,1




1356


37,6


49,5




1357


37,8


44,4




1358


37,8


43,4




1359


37,8


34,8




1360


37,6


24,0




1361


37,2


m




1362


36,3


m




1363


35,1


m




1364


33,7


m




1365


32,4


m




1366


31,1


m




1367


29,9


m




1368


28,7


m




1369


29,0


58,6




1370


29,7


88,5




1371


31,0


86,3




1372


31,8


43,4




1373


31,7


m




1374


29,9


m




1375


40,2


0,0




1376


50,4


m




1377


47,9


m




1378


45,0


m




1379


43,0


m




1380


40,6


m




1381


55,5


0,0




1382


70,4


41,7




1383


73,4


83,2




1384


74,0


83,7




1385


74,9


41,7




1386


60,0


0,0




1387


45,1


41,6




1388


47,7


84,2




1389


50,4


50,2




1390


53,0


26,1




1391


59,5


0,0




1392


66,2


38,4




1393


66,4


76,7




1394


67,6


100,0




1395


68,4


76,6




1396


68,2


47,2




1397


69,0


81,4




1398


69,7


40,6




1399


54,7


0,0




1400


39,8


19,9




1401


36,3


40,0




1402


36,7


59,4




1403


36,6


77,5




1404


36,8


94,3




1405


36,8


100,0




1406


36,4


100,0




1407


36,3


79,7




1408


36,7


49,5




1409


36,6


39,3




1410


37,3


62,8




1411


38,1


73,4




1412


39,0


72,9




1413


40,2


72,0




1414


41,5


71,2




1415


42,9


77,3




1416


44,4


76,6




1417


45,4


43,1




1418


45,3


53,9




1419


45,1


64,8




1420


46,5


74,2




1421


47,7


75,2




1422


48,1


75,5




1423


48,6


75,8




1424


48,9


76,3




1425


49,9


75,5




1426


50,4


75,2




1427


51,1


74,6




1428


51,9


75,0




1429


52,7


37,2




1430


41,6


0,0




1431


30,4


36,6




1432


30,5


73,2




1433


30,3


81,6




1434


30,4


89,3




1435


31,5


90,4




1436


32,7


88,5




1437


33,7


97,2




1438


35,2


99,7




1439


36,3


98,8




1440


37,7


100,0




1441


39,2


100,0




1442


40,9


100,0




1443


42,4


99,5




1444


43,8


98,7




1445


45,4


97,3




1446


47,0


96,6




1447


47,8


96,2




1448


48,8


96,3




1449


50,5


95,1




1450


51,0


95,9




1451


52,0


94,3




1452


52,6


94,6




1453


53,0


65,5




1454


53,2


0,0




1455


53,2


m




1456


52,6


m




1457


52,1


m




1458


51,8


m




1459


51,3


m




1460


50,7


m




1461


50,7


m




1462


49,8


m




1463


49,4


m




1464


49,3


m




1465


49,1


m




1466


49,1


m




1467


49,1


8,3




1468


48,9


16,8




1469


48,8


21,3




1470


49,1


22,1




1471


49,4


26,3




1472


49,8


39,2




1473


50,4


83,4




1474


51,4


90,6




1475


52,3


93,8




1476


53,3


94,0




1477


54,2


94,1




1478


54,9


94,3




1479


55,7


94,6




1480


56,1


94,9




1481


56,3


86,2




1482


56,2


64,1




1483


56,0


46,1




1484


56,2


33,4




1485


56,5


23,6




1486


56,3


18,6




1487


55,7


16,2




1488


56,0


15,9




1489


55,9


21,8




1490


55,8


20,9




1491


55,4


18,4




1492


55,7


25,1




1493


56,0


27,7




1494


55,8


22,4




1495


56,1


20,0




1496


55,7


17,4




1497


55,9


20,9




1498


56,0


22,9




1499


56,0


21,1




1500


55,1


19,2




1501


55,6


24,2




1502


55,4


25,6




1503


55,7


24,7




1504


55,9


24,0




1505


55,4


23,5




1506


55,7


30,9




1507


55,4


42,5




1508


55,3


25,8




1509


55,4


1,3




1510


55,0


m




1511


54,4


m




1512


54,2


m




1513


53,5


m




1514


52,4


m




1515


51,8


m




1516


50,7


m




1517


49,9


m




1518


49,1


m




1519


47,7


m




1520


47,3


m




1521


46,9


m




1522


46,9


m




1523


47,2


m




1524


47,8


m




1525


48,2


0,0




1526


48,8


23,0




1527


49,1


67,9




1528


49,4


73,7




1529


49,8


75,0




1530


50,4


75,8




1531


51,4


73,9




1532


52,3


72,2




1533


53,3


71,2




1534


54,6


71,2




1535


55,4


68,7




1536


56,7


67,0




1537


57,2


64,6




1538


57,3


61,9




1539


57,0


59,5




1540


56,7


57,0




1541


56,7


69,8




1542


56,8


58,5




1543


56,8


47,2




1544


57,0


38,5




1545


57,0


32,8




1546


56,8


30,2




1547


57,0


27,0




1548


56,9


26,2




1549


56,7


26,2




1550


57,0


26,6




1551


56,7


27,8




1552


56,7


29,7




1553


56,8


32,1




1554


56,5


34,9




1555


56,6


34,9




1556


56,3


35,8




1557


56,6


36,6




1558


56,2


37,6




1559


56,6


38,2




1560


56,2


37,9




1561


56,6


37,5




1562


56,4


36,7




1563


56,5


34,8




1564


56,5


35,8




1565


56,5


36,2




1566


56,5


36,7




1567


56,7


37,8




1568


56,7


37,8




1569


56,6


36,6




1570


56,8


36,1




1571


56,5


36,8




1572


56,9


35,9




1573


56,7


35,0




1574


56,5


36,0




1575


56,4


36,5




1576


56,5


38,0




1577


56,5


39,9




1578


56,4


42,1




1579


56,5


47,0




1580


56,4


48,0




1581


56,1


49,1




1582


56,4


48,9




1583


56,4


48,2




1584


56,5


48,3




1585


56,5


47,9




1586


56,6


46,8




1587


56,6


46,2




1588


56,5


44,4




1589


56,8


42,9




1590


56,5


42,8




1591


56,7


43,2




1592


56,5


42,8




1593


56,9


42,2




1594


56,5


43,1




1595


56,5


42,9




1596


56,7


42,7




1597


56,6


41,5




1598


56,9


41,8




1599


56,6


41,9




1600


56,7


42,6




1601


56,7


42,6




1602


56,7


41,5




1603


56,7


42,2




1604


56,5


42,2




1605


56,8


41,9




1606


56,5


42,0




1607


56,7


42,1




1608


56,4


41,9




1609


56,7


42,9




1610


56,7


41,8




1611


56,7


41,9




1612


56,8


42,0




1613


56,7


41,5




1614


56,6


41,9




1615


56,8


41,6




1616


56,6


41,6




1617


56,9


42,0




1618


56,7


40,7




1619


56,7


39,3




1620


56,5


41,4




1621


56,4


44,9




1622


56,8


45,2




1623


56,6


43,6




1624


56,8


42,2




1625


56,5


42,3




1626


56,5


44,4




1627


56,9


45,1




1628


56,4


45,0




1629


56,7


46,3




1630


56,7


45,5




1631


56,8


45,0




1632


56,7


44,9




1633


56,6


45,2




1634


56,8


46,0




1635


56,5


46,6




1636


56,6


48,3




1637


56,4


48,6




1638


56,6


50,3




1639


56,3


51,9




1640


56,5


54,1




1641


56,3


54,9




1642


56,4


55,0




1643


56,4


56,2




1644


56,2


58,6




1645


56,2


59,1




1646


56,2


62,5




1647


56,4


62,8




1648


56,0


64,7




1649


56,4


65,6




1650


56,2


67,7




1651


55,9


68,9




1652


56,1


68,9




1653


55,8


69,5




1654


56,0


69,8




1655


56,2


69,3




1656


56,2


69,8




1657


56,4


69,2




1658


56,3


68,7




1659


56,2


69,4




1660


56,2


69,5




1661


56,2


70,0




1662


56,4


69,7




1663


56,2


70,2




1664


56,4


70,5




1665


56,1


70,5




1666


56,5


69,7




1667


56,2


69,3




1668


56,5


70,9




1669


56,4


70,8




1670


56,3


71,1




1671


56,4


71,0




1672


56,7


68,6




1673


56,8


68,6




1674


56,6


68,0




1675


56,8


65,1




1676


56,9


60,9




1677


57,1


57,4




1678


57,1


54,3




1679


57,0


48,6




1680


57,4


44,1




1681


57,4


40,2




1682


57,6


36,9




1683


57,5


34,2




1684


57,4


31,1




1685


57,5


25,9




1686


57,5


20,7




1687


57,6


16,4




1688


57,6


12,4




1689


57,6


8,9




1690


57,5


8,0




1691


57,5


5,8




1692


57,3


5,8




1693


57,6


5,5




1694


57,3


4,5




1695


57,2


3,2




1696


57,2


3,1




1697


57,3


4,9




1698


57,3


4,2




1699


56,9


5,5




1700


57,1


5,1




1701


57,0


5,2




1702


56,9


5,5




1703


56,6


5,4




1704


57,1


6,1




1705


56,7


5,7




1706


56,8


5,8




1707


57,0


6,1




1708


56,7


5,9




1709


57,0


6,6




1710


56,9


6,4




1711


56,7


6,7




1712


56,9


6,9




1713


56,8


5,6




1714


56,6


5,1




1715


56,6


6,5




1716


56,5


10,0




1717


56,6


12,4




1718


56,5


14,5




1719


56,6


16,3




1720


56,3


18,1




1721


56,6


20,7




1722


56,1


22,6




1723


56,3


25,8




1724


56,4


27,7




1725


56,0


29,7




1726


56,1


32,6




1727


55,9


34,9




1728


55,9


36,4




1729


56,0


39,2




1730


55,9


41,4




1731


55,5


44,2




1732


55,9


46,4




1733


55,8


48,3




1734


55,6


49,1




1735


55,8


49,3




1736


55,9


47,7




1737


55,9


47,4




1738


55,8


46,9




1739


56,1


46,8




1740


56,1


45,8




1741


56,2


46,0




1742


56,3


45,9




1743


56,3


45,9




1744


56,2


44,6




1745


56,2


46,0




1746


56,4


46,2




1747


55,8


m




1748


55,5


m




1749


55,0


m




1750


54,1


m




1751


54,0


m




1752


53,3


m




1753


52,6


m




1754


51,8


m




1755


50,7


m




1756


49,9


m




1757


49,1


m




1758


47,7


m




1759


46,8


m




1760


45,7


m




1761


44,8


m




1762


43,9


m




1763


42,9


m




1764


41,5


m




1765


39,5


m




1766


36,7


m




1767


33,8


m




1768


31,0


m




1769


40,0


0,0




1770


49,1


m




1771


46,2


m




1772


43,1


m




1773


39,9


m




1774


36,6


m




1775


33,6


m




1776


30,5


m




1777


42,8


0,0




1778


55,2


m




1779


49,9


m




1780


44,0


m




1781


37,6


m




1782


47,2


0,0




1783


56,8


m




1784


47,5


m




1785


42,9


m




1786


31,6


m




1787


25,8


m




1788


19,9


m




1789


14,0


m




1790


8,1


m




1791


2,2


m




1792


0,0


0,0




1793


0,0


0,0




1794


0,0


0,0




1795


0,0


0,0




1796


0,0


0,0




1797


0,0


0,0




1798


0,0


0,0




1799


0,0


0,0




1800


0,0


0,0




m = motoring








‘APPENDIX 2
DIESEL REFERENCE FUEL









Parameter


Unit


Limits (2)



Test method (6)





Minimum


Maximum




Cetene number


 


52


54


ISO 5165




Density at 15 °C


kg/m3



833


837


ISO 3675




Distillation:


 


 


 


 










—


50 per cent vol.






°C


245


 


ISO 3405










—


95 per cent vol.






°C


345


350


 










—


final boiling point






°C


 


370


 




Flash point


°C


55


 


ISO 2719




Cold filter plugging point


°C


 


–5 


EN 116




Kinematic viscosity at 40 °C


mm2/s


2,3


3,3


ISO 3104




Polycylic aromatic hydrocarbons


per cent m/m


2,0


6,0


EN 12916




Conradson carbon residue (10 per cent DR)


per cent m/m


 


0,2


ISO 10370




Ash content


per cent m/m


 


0,01


EN-ISO 6245




Water content


per cent m/m


 


0,02


EN-ISO12937




Sulfur content


mg/kg


 


10


EN-ISO14596




Copper corrosion at 50 °C


 


 


1


EN-ISO 2160




Lubricity (HFRR at 60 °C)


µm


 


400


CEC F-06-A-96




Neutralisation number


mg KOH/g


 


0,02


 




Oxidation stability @ 110 °C (3)
 (4)



h


20


 


EN 14112




FAME (5)



per cent v/v


4,5


5,5


EN 14078








‘APPENDIX 3
MEASUREMENT EQUIPMENT
This Appendix contains the basic requirements and the general descriptions of the sampling and analysing systems for gaseous and particulate emissions measurement. Since various configurations can produce equivalent results, exact conformance with the figures of this Appendix is not required. Components such as instruments, valves, solenoids, pumps, flow devices 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.
A.3.1.1.   Analytical system
A.3.1.2.   Description of the analytical system
Analytical system for the determination of the gaseous emissions in the raw exhaust gas (figure 9) or in the diluted exhaust gas (figure 10) are described based on the use of:






(a)


HFID or FID analyser for the measurement of hydrocarbons;










(b)


NDIR analysers for the measurement of carbon monoxide and carbon dioxide;










(c)


HCLD or CLD analyser for the measurement of the oxides of nitrogen.




The sample for all components should be taken with one sampling probe and internally split to the different analysers. Optionally, two sampling probes located in close proximity may be used. Care shall be taken that no unintended condensation of exhaust components (including water and sulphuric acid) occurs at any point of the analytical system.




Figure 9


Schematic flow diagram of raw exhaust gas analysis system for CO, CO2, NOx, HC

a = vent
b = zero, span gas
c = exhaust pipe
d = optional




Figure 10


Schematic flow diagram of diluted exhaust gas analysis system for CO, CO2, NOx, HC

a = vent
b = zero, span gas
c = dilution tunnel
d = optional
A.3.1.3.   Components of figures 9 and 10






EP


Exhaust pipe




SP


Raw exhaust gas sampling probe (figure 9 only)




A stainless steel straight closed end multi-hole 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 3 holes in 3 different radial planes sized to sample approximately the same flow. The probe shall extend across at least 80 per cent of the diameter of the exhaust pipe. One or two sampling probes may be used.






SP2


Dilute exhaust gas HC sampling probe (figure 10 only)




The probe shall:






(a)


be defined as the first 254 mm to 762 mm of the heated sampling line HSL1,










(b)


have a 5 mm minimum inside diameter,










(c)


be installed in the dilution tunnel DT (figure 15) at a point where the diluent and exhaust gas are well mixed (i.e. approximately 10 tunnel diameters downstream of the point where the exhaust enters the dilution tunnel),










(d)


be sufficiently distant (radially) from other probes and the tunnel wall so as to be free from the influence of any wakes or eddies,










(e)


be heated so as to increase the gas stream temperature to 463 K ± 10 K (190 °C ± 10 °C) at the exit of the probe, or to 385 K ± 10 K (112 °C ± 10 °C) for positive ignition engines,










(f)


non-heated in case of FID measurement (cold).










SP3


Dilute exhaust gas CO, CO2, NOx sampling probe (figure 10 only)




The probe shall:






(a)


be in the same plane as SP2,










(b)


be sufficiently distant (radially) from other probes and the tunnel wall so as to be free from the influence of any wakes or eddies,










(c)


be heated and insulated over its entire length to a minimum temperature of 328 K (55 °C) to prevent water condensation.










HF1


Heated pre-filter (optional)




The temperature shall be the same as HSL1.






HF2


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.






HSL1


Heated sampling line




The sampling line provides a gas sample from a single probe to the split point(s) and the HC analyser.
The sampling line shall:






(a)


have a 4 mm minimum and a 13,5 mm maximum inside diameter;










(b)


be made of stainless steel or PTFE;










(c)


maintain a wall temperature of 463 K ± 10 K (190 °C ± 10 °C) as measured at every separately controlled heated section, if the temperature of the exhaust gas at the sampling probe is equal to or below 463 K (190 °C);










(d)


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);










(e)


maintain a gas temperature of 463 K ± 10 K (190 °C ± 10 °C) immediately before the heated filter HF2 and the HFID.










HSL2


Heated NOx sampling line




The sampling line shall:






(a)


maintain 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 analyser for wet measurement;










(b)


be made of stainless steel or PTFE.










HP


Heated sampling pump




The pump shall be heated to the temperature of HSL.






SL


Sampling line for CO and CO2





The line shall be made of PTFE or stainless steel. It may be heated or unheated.






HC


HFID analyser




Heated flame ionisation detector (HFID) or flame ionisation detector (FID) for the determination of the hydrocarbons. The temperature of the HFID shall be kept at 453 K to 473 K (180 °C to 200 °C).






CO, CO2



NDIR analyser




NDIR analysers for the determination of carbon monoxide and carbon dioxide (optional for the determination of the dilution ratio for PT measurement).






NOx



CLD analyser or NDUV analyser




CLD, HCLD or NDUV analyser for the determination of the oxides of nitrogen. If a HCLD is used it shall be kept at a temperature of 328 K to 473 K (55 °C to 200 °C).






B


Sample dryer (optional for NO measurement)




To cool and condense water from the exhaust sample. It is optional if the analyser is free from water vapour interference as determined in paragraph 9.3.9.2.2. If water is removed by condensation, the sample gas temperature or dew point shall be monitored either within the water trap or downstream. The sample gas temperature or dew point shall not exceed 280 K (7 °C). Chemical dryers are not allowed for removing water from the sample.






BK


Background bag (optional; figure 10 only)




For the measurement of the background concentrations.






BG


Sample bag (optional; figure 10 only)




For the measurement of the sample concentrations.
A.3.1.4.   Non-methane cutter method (NMC)
The cutter oxidises all hydrocarbons except CH4 to CO2 and H2O, so that by passing the sample through the NMC only CH4 is detected by the HFID. In addition to the usual HC sampling train (see figures 9 and 10), a second HC sampling train shall be installed equipped with a cutter as laid out in figure 11. This allows simultaneous measurement of total HC, CH4 and NMHC.
The cutter shall be characterised at or above 600 K (327 °C) prior to test work with respect to its catalytic effect on CH4 and C2H6 at H2O values representative of exhaust stream conditions. The dew point and O2 level of the sampled exhaust stream shall be known. The relative response of the FID to CH4 and C2H6 shall be determined in accordance with paragraph 9.3.8.




Figure 11


Schematic flow diagram of methane analysis with the NMC

zero, span gas
Vent
Sample
Vent
Vent
Vent
A.3.1.5.   Components of figure 11






NMC


Non-methane cutter




To oxidise all hydrocarbons except methane
HC
Heated flame ionisation detector (HFID) or flame ionisation detector (FID) to measure the HC and CH4 concentrations. The temperature of the HFID shall be kept at 453 K to 473 K (180 °C to 200 °C).






V1


Selector valve




To select zero and span gas






R


Pressure regulator




To control the pressure in the sampling line and the flow to the HFID
A.3.2.   Dilution and particulate sampling system
A.3.2.1.   Description of partial flow system
A dilution system is described based upon 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 is passed to the particulate sampling system. The first method is referred to as total sampling type, the second method as fractional sampling type. The calculation of the dilution ratio depends upon the type of system used.
With the total sampling system as shown in figure 12, 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 FC2 and the sampling pump (P) of the particulate sampling system (see figure 16). The dilution airflow is controlled by the flow controller FC1, which may use qm

ew or qm

aw and qm

f as command signals, for the desired exhaust split. The sample flow into DT is the difference of the total flow and the dilution airflow. The dilution airflow rate is measured with the flow measurement device FM1, the total flow rate with the flow measurement device FM3 of the particulate sampling system (see figure 16). The dilution ratio is calculated from these two flow rates.




Figure 12


Scheme of partial flow dilution system (total sampling type)

a = exhaust
b = optional
c = details see Figure 16
With the fractional sampling system as shown in figure 13, 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 FC1 connected either to the dilution airflow or to the suction blower for the total tunnel flow. The flow controller FC1 may use qm

ew or qm

aw and qm

f as command signals for the desired exhaust split. The sample flow into DT is the difference of the total flow and the dilution airflow. The dilution airflow rate is measured with the flow measurement device FM1, the total flow rate with the flow measurement device FM2. The dilution ratio is calculated from these two flow rates. From DT, a particulate sample is taken with the particulate sampling system (see figure 16).




Figure 13


Scheme of partial flow dilution system (fractional sampling type)

a = exhaust
b = to PB or SB
c = details see Figure 16
d = to particulate sampling system
e = vent
A.3.2.2.   Components of figures 12 and 13






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 shall be minimised to reduce inertial deposition. If the system includes a test bed silencer the silencer may also be insulated. It is recommended to have a straight pipe of 6 pipe diameters upstream and 3 pipe diameters downstream of the tip of the probe.






SP


Sampling probe




The type of probe shall be either of the following






(a)


open tube facing upstream on the exhaust pipe centreline;










(b)


open tube facing downstream on the exhaust pipe centreline;










(c)


multiple hole probe as described under SP in paragraph A.3.1.3;










(d)


hatted probe facing upstream on the exhaust pipe centreline as shown in figure 14.




The minimum inside diameter of the probe tip shall be 4 mm. The minimum diameter ratio between exhaust pipe and probe shall be 4.
When using probe type (a), an inertial pre-classifier (cyclone or impactor) with at 50 per cent cut point between 2,5 and 10 µm shall be installed immediately upstream of the filter holder.




Figure 14


Scheme of hatted probe

cross-section
Flow






TT


Exhaust transfer tube




The transfer tube shall be as short as possible, but:






(a)


not more than 0,26 m in length, if insulated for 80 per cent of the total length, as measured between the end of the probe and the dilution stage,
or










(b)


not more than 1 m in length, if heated above 150 °C for 90 per cent of the total length, as measured between the end of the probe and the dilution stage.




It shall be equal to or greater than the probe diameter, but not more than 25 mm in diameter, and exiting on the centreline of the dilution tunnel and pointing downstream.
With respect to (a), insulation shall be done with material with a maximum thermal conductivity of 0,05 W/mK with a radial insulation thickness corresponding to the diameter of the probe.






FC1


Flow controller




A flow controller shall be used to control the dilution airflow through the pressure blower PB and/or the suction blower SB. It may be connected to the exhaust flow sensor signals specified in paragraph 8.4.1. The flow controller may be installed upstream or downstream of the respective blower. When using a pressurised air supply, FC1 directly controls the airflow.






FM1


Flow measurement device




Gas meter or other flow instrumentation to measure the dilution airflow. FM1 is optional if the pressure blower PB is calibrated to measure the flow.






DAF


Diluent filter




The diluent (ambient air, synthetic air, or nitrogen) shall be filtered with a high-efficiency (HEPA) filter that has an initial minimum collection efficiency of 99,97 per cent according to EN 1822-1 (filter class H14 or better), ASTM F 1471-93 or equivalent standard.






FM2


Flow measurement device (fractional sampling type, figure 13 only)




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 (fractional sampling type, figure 13 only)




To control the dilution airflow 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 airflow, if calibrated.






SB


Suction blower (fractional sampling type, figure 13 only)




SB may be used to measure the diluted exhaust gas flow, if calibrated.






DT


Dilution tunnel (partial flow)




The dilution tunnel:






(a)


shall be of a sufficient length to cause complete mixing of the exhaust and diluent under turbulent flow conditions (Reynolds number, Re, greater than 4 000, where Re is based on the inside diameter of the dilution tunnel) for a fractional sampling system, i.e. complete mixing is not required for a total sampling system,










(b)


shall be constructed of stainless steel,










(c)


may be heated to no greater than 325 K (52 °C) wall temperature,










(d)


may be insulated.










PSP


Particulate sampling probe (fractional sampling type, figure 13 only)




The particulate sampling probe is the leading section of the particulate transfer tube PTT (see paragraph A.3.2.6) and:






(a)


shall be installed facing upstream at a point where the diluent and exhaust gas are well mixed, i.e. on the dilution tunnel DT centreline approximately 10 tunnel diameters downstream of the point where the exhaust enters the dilution tunnel,










(b)


shall be 8 mm in minimum inside diameter,










(c)


may be heated to no greater than 325 K (52 °C) wall temperature by direct heating or by diluent pre-heating, provided the diluent temperature does not exceed 325 K (52 °C) prior to the introduction of the exhaust into the dilution tunnel,










(d)


may be insulated.




A.3.2.3.   Description of full flow dilution system
A dilution system is described based upon the dilution of the total amount of raw exhaust gas in the dilution tunnel DT using the CVS (constant volume sampling) concept, and is shown in figure 15.
The diluted exhaust gas flow rate shall be measured either with a positive displacement pump (PDP), with a critical flow venturi (CFV) or with a subsonic 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, it is not necessary to calculate the dilution ratio.
For subsequent collection of the particulates, a sample of the dilute exhaust gas shall be passed to the double dilution particulate sampling system (see figure 17). Although partly a dilution system, the double dilution system is described as a modification of a particulate sampling system, since it shares most of the parts with a typical particulate sampling system.




Figure 15


Scheme of full flow dilution system (CVS)

a = analyser system
b = background air
c = exhaust
d = details see Figure 17
e = to double dilution system
f = if EFC is used
i = vent
g = optional
h = or
A.3.2.4.   Components of figure 15






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 shall 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 shall be at least 25 mm. The thermal conductivity of the insulating material shall have a value no greater than 0,1 W/mK measured at 673 K. 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.






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 backpressure shall not be artificially lowered by the PDP or diluent inlet system. Static exhaust backpressure measured with the PDP system operating shall remain within ±1,5 kPa of the static pressure measured without connection to the PDP 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 (EFC) is used. Flow compensation is only permitted, if the temperature at the inlet to the PDP does not exceed 323 K (50 °C).






CFV


Critical flow venturi




CFV measures total diluted exhaust flow by maintaining the flow at chocked 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 (EFC) is used.






SSV


Subsonic venturi




SSV measures total diluted exhaust flow by using the gas flow function of a subsonic venturi in dependence of inlet pressure and temperature and pressure drop between venturi 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 (EFC) is used.






HE


Heat exchanger (optional)




The heat exchanger shall be of sufficient capacity to maintain the temperature within the limits required above. If EFC is used, the heat exchanger is not required.






EFC


Electronic flow compensation (optional)




If the temperature at the inlet to the PDP, 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 into the double dilution system. For that purpose, the continuously measured flow rate signals are used to maintain the proportionality of the sample flow rate through the particulate filters of the double dilution system (see figure 17) within ±2,5 per cent.






DT


Dilution tunnel (full flow)




The dilution tunnel






(a)


shall be small enough in diameter to cause turbulent flow (Reynolds number, Re, greater than 4 000, where Re is based on the inside diameter of the dilution tunnel) and of sufficient length to cause complete mixing of the exhaust and diluent,










(b)


may be insulated,










(c)


may be heated up to a wall temperature sufficient to eliminate aqueous condensation.




The engine exhaust shall be directed downstream at the point where it is introduced into the dilution tunnel, and thoroughly mixed. A mixing orifice may be used.
For the double dilution system, 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 (figure 17). The secondary dilution system shall provide sufficient secondary diluent to maintain the doubly diluted exhaust stream at a temperature between 315 K (42 °C) and 325 K (52 °C) immediately before the particulate filter.






DAF


Diluent filter




The diluent (ambient air, synthetic air, or nitrogen) shall be filtered with a high-efficiency (HEPA) filter that has an initial minimum collection efficiency of 99,97 per cent according to EN 1822-1 (filter class H14 or better), ASTM F 1471-93 or equivalent standard.






PSP


Particulate sampling probe




The probe is the leading section of PTT and






(a)


shall be installed facing upstream at a point where the diluent and exhaust gases are well mixed, i.e. on the dilution tunnel DT centreline of the dilution systems, approximately 10 tunnel diameters downstream of the point where the exhaust enters the dilution tunnel;










(b)


shall be of 8 mm minimum inside diameter;










(c)


may be heated to no greater than 325 K (52 °C) wall temperature by direct heating or by diluent pre-heating, provided the air temperature does not exceed 325 K (52 °C) prior to the introduction of the exhaust in the dilution tunnel;










(d)


may be insulated.




A.3.2.5.   Description of particulate sampling system
The particulate sampling system is required for collecting the particulates on the particulate filter and is shown in figures 16 and 17. In the case of total sampling partial flow dilution, which consists of passing the entire diluted exhaust sample through the filters, the dilution and sampling systems usually form an integral unit (see figure 12). 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 and sampling systems usually form different units.
For a partial flow dilution system, a sample of the diluted exhaust gas is taken from the dilution tunnel DT through the particulate sampling probe PSP and the particulate transfer tube PTT by means of the sampling pump P, as shown in figure 16. The sample is passed through the filter holder(s) FH that contain the particulate sampling filters. The sample flow rate is controlled by the flow controller FC3.
For of full flow dilution system, a double dilution particulate sampling system shall be used, as shown in figure 17. A sample of the diluted exhaust gas is transferred from the dilution tunnel DT 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 airflow rate is usually constant whereas the sample flow rate is controlled by the flow controller FC3. If electronic flow compensation EFC (see figure 15) is used, the total diluted exhaust gas flow is used as command signal for FC3.




Figure 16


Scheme of particulate sampling system

a = from dilution tunnel




Figure 17


Scheme of double dilution particulate sampling system

a = diluted exhaust from DT
b = optional
c = vent
d = secondary diluent
A.3.2.6.   Components of figures 16 (partial flow system only) and 17 (full flow system only)






PTT


Particulate transfer tube




The transfer tube:






(a)


shall be inert with respect to PM,










(b)


may be heated to no greater than 325 K (52 °C) wall temperature,










(c)


may be insulated.










SDT


Secondary dilution tunnel (figure 17 only)




The secondary dilution tunnel:






(a)


shall be of sufficient length and diameter so as to comply with the residence time requirements of paragraph 9.4.2(f);










(b)


may be heated to no greater than 325 K (52 °C) wall temperature;










(c)


may be insulated.










FH


Filter holder




The filter holder:






(a)


shall have a 12,5° (from centre) divergent cone angle to transition from the transfer line diameter to the exposed diameter of the filter face;










(b)


may be heated to no greater than 325 K (52 °C) wall temperature;










(c)


may be insulated.




Multiple filter changers (auto changers) are acceptable, as long as there is no interaction between sampling filters.
PTFE membrane filters shall be installed in a specific cassette within the filter holder.
An inertial pre-classifier with a 50 per cent cut point between 2,5 µm and 10 µm shall be installed immediately upstream of the filter holder, if an open tube sampling probe facing upstream is used.






P


Sampling pump




FC2


Flow controller




A flow controller shall be used for controlling the particulate sample flow rate.






FM3


Flow measurement device




Gas meter or flow instrumentation to determine the particulate sample flow through the particulate filter. It may be installed upstream or downstream of the sampling pump P.






FM4


Flow measurement device




Gas meter or flow instrumentation to determine the secondary dilution airflow through the particulate filter.






BV


Ball valve (optional)




The ball valve shall have an inside diameter not less than the inside diameter of the particulate transfer tube PTT, and a switching time of less than 0,5 s.




‘APPENDIX 4
STATISTICS
A.4.1.   Mean value and standard deviation
The arithmetic mean value shall be calculated as follows:



 (92)
The standard deviation shall be calculated as follows:



 (93)
A.4.2.   Regression analysis
The slope of the regression shall be calculated as follows:



 (94)
The y intercept of the regression shall be calculated as follows:



 (95)
The standard error of estimate (SEE) shall be calculated as follows:



 (96)
The coefficient of determination shall be calculated as follows:



 (97)
A.4.3.   Determination of system equivalency
The determination of system equivalency according to paragraph 5.1.1 shall be based on a 7 sample pair (or larger) correlation study between the candidate system and one of the accepted reference systems of this Annex using the appropriate test cycle(s). The equivalency criteria to be applied shall be the F-test and the two-sided Student t-test.
This statistical method examines the hypothesis that the sample standard deviation and sample mean value for an emission measured with the candidate system do not differ from the sample standard deviation and sample mean value for that emission measured with the reference system. The hypothesis shall be tested on the basis of a 10 per cent significance level of the F and t values. The critical F and t values for 7 to 10 sample pairs are given in table 9. If the F and t values calculated according to the equation below are greater than the critical F and t values, the candidate system is not equivalent.
The following procedure shall be followed. The subscripts R and C refer to the reference and candidate system, respectively:






(a)


Conduct at least 7 tests with the candidate and reference systems operated in parallel. The number of tests is referred to as n
R and n
C.










(b)

Calculate the mean values 



 and 



 and the standard deviations s
R and s
C.









(c)


Calculate the F value, as follows:



 (98)
(the greater of the two standard deviations s
R or s
C shall be in the numerator)










(d)


Calculate the t value, as follows:



 (99)










(e)


Compare the calculated F and t values with the critical F and t values corresponding to the respective number of tests indicated in table 9. If larger sample sizes are selected, consult statistical tables for 10 per cent significance (90 per cent confidence) level.










(f)


Determine the degrees of freedom (df), as follows:







for the F-test:






, 






(100)




for the t-test:









(101)














(g)


Determine the equivalency, as follows:






(i)


if F < F
crit and t < t
crit, then the candidate system is equivalent to the reference system of this Annex










(ii)


if F ≥ F
crit or t ≥ t
crit, then the candidate system is different from the reference system of this Annex








Table 9

t and F values for selected sample sizes









Sample Size



F-test



t-test




 



df




F
crit




df




t
crit





7


6,6


3,055


6


1,943




8


7,7


2,785


7


1,895




9


8,8


2,589


8


1,860




10


9,9


2,440


9


1,833








‘APPENDIX 5
CARBON FLOW CHECK
A.5.1.   Introduction
All but a tiny part of the carbon in the exhaust comes from the fuel, and all but a minimal part of this is manifest in the exhaust gas as CO2. This is the basis for a system verification check based on CO2 measurements.
The flow of carbon into the exhaust measurement systems is determined from the fuel flow rate. The flow of carbon at various sampling points in the emissions and particulate sampling systems is determined from the CO2 concentrations and gas flow rates at those points.
In this sense, the engine provides a known source of carbon flow, and observing the same carbon flow in the exhaust pipe and at the outlet of the partial flow PM sampling system verifies leak integrity and flow measurement accuracy. This check has the advantage that the components are operating under actual engine test conditions of temperature and flow.
Figure 18 shows the sampling points at which the carbon flows shall be checked. The specific equations for the carbon flows at each of the sample points are given below.




Figure 18


Measuring points for carbon flow check

Air
Fuel
CO2RAW
ENGINE
CO2PFS
Partial Flow System
A.5.2.   Carbon flow rate into the engine (location 1)
The carbon mass flow rate into the engine for a fuel CH
α
O
ε
 is given by:



 (102)
where:







qm

f



is the fuel mass flow rate, kg/s




A.5.3.   Carbon flow rate in the raw exhaust (location 2)
The carbon mass flow rate in the exhaust pipe of the engine shall be determined from the raw CO2 concentration and the exhaust gas mass flow rate:



 (103)
where:







c
CO2,r



is the wet CO2 concentration in the raw exhaust gas, per cent





c
CO2,a



is the wet CO2 concentration in the ambient air, per cent





qm

ew



is the exhaust gas mass flow rate on wet basis, kg/s





M
e



is the molar mass of exhaust gas, g/mol




If CO2 is measured on a dry basis it shall be converted to a wet basis according to paragraph 8.1.
A.5.4.   Carbon flow rate in the dilution system (location 3)
For the partial flow dilution system, the splitting ratio also needs to be taken into account. The carbon flow rate shall be determined from the dilute CO2 concentration, the exhaust gas mass flow rate and the sample flow rate:



 (104)
where:







c
CO2,d



is the wet CO2 concentration in the dilute exhaust gas at the outlet of the dilution tunnel, per cent





c
CO2,a



is the wet CO2 concentration in the ambient air, per cent





qm

ew



is the exhaust gas mass flow rate on wet basis, kg/s





qm

p



is the sample flow of exhaust gas into partial flow dilution system, kg/s





M
e



is the molar mass of exhaust gas, g/mol




If CO2 is measured on a dry basis, it shall be converted to wet basis according to paragraph 8.1.
A.5.5.   Calculation of the molar mass of the exhaust gas
The molar mass of the exhaust gas shall be calculated according to equation 41 (see paragraph 8.4.2.4)
Alternatively, the following exhaust gas molar masses may be used:








M
e (diesel)


=


28,9 g/mol





M
e (LPG)


=


28,6 g/mol





M
e (NG)


=


28,3 g/mol








‘APPENDIX 6
EXAMPLE OF CALCULATION PROCEDURE
A.6.1.   Speed and torque denormalisation procedure
As an example, the following test point shall be denormalised:







per cent speed


=


43 per cent




per cent torque


=


82 per cent




Given the following values:








n
lo



=


1 015 min–1






n
hi



=


2 200 min–1






n
pref



=


1 300 min–1






n
idle



=


600 min–1





results in:






actual speed

= 








 


= 1 178  min–1





With the maximum torque of 700 Nm observed from the mapping curve at 1 178 min–1

actual torque = 

 = 574 Nm
A.6.2.   Basic data for stoichiometric calculations






Atomic mass of hydrogen


1,00794 g/atom




Atomic mass of carbon


12,011 g/atom




Atomic mass of sulphur


32,065 g/atom




Atomic mass of nitrogen


14,0067 g/atom




Atomic mass of oxygen


15,9994 g/atom




Atomic mass of argon


39,9 g/atom




Molar mass of water


18,01534 g/mol




Molar mass of carbon dioxide


44,01 g/mol




Molar mass of carbon monoxide


28,011 g/mol




Molar mass of oxygen


31,9988 g/mol




Molar mass of nitrogen


28,011 g/mol




Molar mass of nitric oxide


30,008 g/mol




Molar mass of nitrogen dioxide


46,01 g/mol




Molar mass of sulphur dioxide


64,066 g/mol




Molar mass of dry air


28,965 g/mol




Assuming no compressibility effects, all gases involved in the engine intake/combustion/exhaust process can be considered to be ideal and any volumetric calculations shall therefore be based on a molar volume of 22,414 l/mol according to Avogadro’s hypothesis.
A.6.3.   Gaseous emissions (diesel fuel)
The measurement data of an individual point of the test cycle (data sampling rate of 1 Hz) for the calculation of the instantaneous mass emission are shown below. In this example, CO and NOx are measured on a dry basis, HC on a wet basis. The HC concentration is given in propane equivalent (C3) and has to be multiplied by 3 to result in the C1 equivalent. The calculation procedure is identical for the other points of the cycle.
The calculation example shows the rounded intermediate results of the different steps for better illustration. It should be noted that for actual calculation, rounding of intermediate results is not permitted (see paragraph 8).














T
a,i

(K)



H
a,i

(g/kg)



W
act

kWh



qm

ew,i

(kg/s)



qm

aw,i

(kg/s)



qm

f,i

(kg/s)



c
HC,i

(ppm)



c
CO,i

(ppm)



c
NOx,i

(ppm)




295


8,0


40


0,155


0,150


0,005


10


40


500




The following fuel composition is considered:







Component


Molar ratio


per cent mass




H



α = 1,8529



w
ALF = 13,45




C



β = 1,0000



w
BET = 86,50




S



γ = 0,0002



w
GAM = 0,050




N



δ = 0,0000



w
DEL = 0,000




O



ε = 0,0000



w
EPS = 0,000




Step 1: Dry/wet correction (paragraph 8.1):
Equation (16): k
f = 0,055584 × 13,45 - 0,0001083 × 86,5 - 0,0001562 × 0,05 = 0,7382
Equation (13): k
w,a= 

 = 0,9331









Equation (12):



c
CO,i (wet)


=


40 × 0,9331


= 37,3 ppm




 



c
NOx,i (wet)


=


500 × 0,9331


= 466,6 ppm




Step 2: NOx correction for temperature and humidity (paragraph 8.2.1):







Equation (23):









= 0,9576




Step 3: Calculation of the instantaneous emission of each individual point of the cycle (paragraph 8.4.2.3):









Equation (36):



m
HC,i



=


10 × 3 × 0,155


= 4,650




 



m
CO,i



=


37,3 × 0,155


= 5,782




 



m
Nox,I



=


466,6 × 0,9576 × 0,155


= 69,26




Step 4: Calculation of the mass emission over the cycle by integration of the instantaneous emission values and the u values from table 5 (paragraph 8.4.2.3):
The following calculation is assumed for the WHTC cycle (1,800 s) and the same emission in each point of the cycle.









Equation (36):



m
HC



=









= 4,01 g/test




 



m
CO



=









= 10,05 g/test




 



m
NOx



=









= 197,72 g/test




Step 5: Calculation of the specific emissions (paragraph 8.6.3):









Equation (69):



e
HC



=


4,01 / 40


= 0,10 g/kWh




 



e
CO



=


10,05 / 40


= 0,25 g/kWh




 



e
NOx



=


197,72 / 40


= 4,94 g/kWh




A.6.4.   Particulate Emission (diesel fuel)















p
b,b

(kPa)



p
b,a

(kPa)



W
act

(kWh)



qm

ew,i

(kg/s)



qm

f,i

(kg/s)



qm

dw,i

(kg/s)



qm

dew,i

(kg/s)



m
uncor,b

(mg)



m
uncor,a

(mg)



m
sep

(kg)




99


100


40


0,155


0,005


0,0015


0,0020


90,0000


91,7000


1,515




Step 1: Calculation of m
edf (paragraph 8.4.3.2.2):









Equation (48):



r
d,i



=









= 4




Equation (47):



qm

edf,i



=


0,155 × 4


= 0,620 kg/s




Equation (46):



m
edf



=









= 1,116 kg/test




Step 2: Buoyancy correction of the particulate mass (paragraph 8.3)
Before test:









Equation (26):



ρ
a,b



=









= 1,164 kg/m3





Equation (25):



m
f,T



=









= 90,0325 mg




After test:









Equation (26):



ρ
a,a



=









= 1,176 kg/m3





Equation (25):



m
f,G



=









= 91,7334 mg




Equation (27):



m
p



=


91,7334 mg – 90,0325 mg


= 1,7009 mg




Step 3: Calculation of the particulate mass emission (paragraph 8.4.3.2.2):









Equation (45):



m
PM



=









= 1,253 g/test




Step 4: Calculation of the specific emission (paragraph 8.6.3):









Equation (69):



e
PM



=


1,253 / 40


= 0,031 g/kWh








‘APPENDIX 7
INSTALLATION OF AUXILIARIES AND EQUIPMENT FOR EMISSIONS TEST







Number


Auxiliaries


Fitted for emission test




1


Inlet system


 




Inlet manifold


Yes




Crankcase emission control system


Yes




Control devices for dual induction inlet manifold system


Yes




Air flow meter


Yes




Air inlet duct work


Yes, or test cell equipment




Air filter


Yes, or test cell equipment




Inlet silencer


Yes, or test cell equipment




Speed-limiting device


Yes




2


Induction-heating device of inlet manifold


Yes, if possible to be set in the most favourable condition




3


Exhaust system


 




Exhaust manifold


Yes




Connecting pipes


Yes




Silencer


Yes




Tail pipe


Yes




Exhaust brake


No, or fully open




Pressure charging device


Yes




4


Fuel supply pump


Yes




5


Equipment for gas engines


 




Electronic control system, air flow meter, etc.


Yes




Pressure reducer


Yes




Evaporator


Yes




Mixer


Yes




6


Fuel injection equipment


 




Pre-filter


Yes




Filter


Yes




Pump


Yes




High-pressure pipe


Yes




Injector


Yes




Air inlet valve


Yes




Electronic control system, sensors, etc.


Yes




Governor/control system


Yes




Automatic full-load stop for the control rack depending on atmospheric conditions


Yes




7


Liquid-cooling equipment


 




Radiator


No




Fan


No




Fan cowl


No




Water pump


Yes




Thermostat


Yes, may be fixed fully open




8


Air cooling


 




Cowl


No




Fan or blower


No




Temperature-regulating device


No




9


Electrical equipment


 




Generator


No




Coil or coils


Yes




Wiring


Yes




Electronic control system


Yes




10


Intake air charging equipment


 




Compressor driven either directly by the engine and/or by the exhaust gases


Yes




Charge air cooler


Yes, or test cell system




Coolant pump or fan (engine-driven)


No




Coolant flow control device


Yes




11


Anti-pollution device (exhaust after-treatment system)


Yes




12


Starting equipment


Yes, or test cell system




13


Lubricating oil pump


Yes







Modify Annex 9B
The title, amend to read:


                     ‘TECHNICAL REQUIREMENTS FOR ON-BOARD DIAGNOSTIC SYSTEMS (OBD)’
                  

Paragraph 1, amend to read:







‘1.


APPLICABILITY
This annex is applicable to diesel or gaseous-fuelled (NG or LPG) engines intended to be mounted in road vehicles, but is not applicable to dual-fuel or bi-fuelled engines.




Note: Annex 9B is applicable instead of Annex 9A upon decision of the Contracting Parties, provided that Annex 4B is also applied. Nevertheless, in the case a Contracting Party decides to apply this Annex, some requirements of Annex 9A may still remain applicable at the explicit request of that Contracting Party, provided that these requirements are not in contradiction to the specifications of this Annex.’
            

Paragraph 3.35, amend to read:







‘3.35.


“Warm-up cycle” means sufficient engine operation such that the coolant temperature has risen by at least 22 K (22 °C / 40 °F) from engine starting and reaches a minimum temperature of 333 K (60 °C / 140 °F) (2).’





Paragraph 3.36, amend to read:







‘3.36.


Abbreviations






CV


Crankcase Ventilation




DOC


Diesel Oxidation Catalyst




DPF


Diesel Particulate Filter or Particulate Trap including catalysed DPFs and Continuously Regenerating Traps (CRT)




DTC


Diagnostic trouble code




EGR


Exhaust Gas Recirculation




HC


Hydrocarbon




LNT


Lean NOx Trap (or NOx absorber)




LPG


Liquefied Petroleum Gas




MECS


Malfunction Emission Control Strategy




NG


Natural Gas




NOx



Oxides of Nitrogen




OTL


OBD Threshold Limit




PM


Particulate Matter




SCR


Selective Catalytic Reduction




SW


Screen Wipers




TFF


Total Functional Failure monitoring




VGT


Variable Geometry Turbocharger




VVT


Variable Valve Timing’









Paragraph 4.3, amend to read:







‘4.3.


Requirements for recording OBD information
When a malfunction …
When a confirmed and active malfunction is no longer detected by the system during a complete operating sequence, it shall be given the previously active status by the start of the next operating sequence and keep that status until the OBD information associated with this malfunction is erased by a scan tool or erased from the computer memory according to paragraph 4.4.’
               





Paragraph 4.7.1.2, item (l), correct ‘active DTCs Class B1’ to read ‘active DTCs for Class B1’.
Paragraph 5.2.3, amend to read:







‘5.2.3.


Low fuel level
Manufacturers may request approval to disable monitoring systems that are affected by low fuel level / pressure or running out of fuel (e.g. diagnosis of a malfunction of the fuelling system or misfiring) as follows:








 


DIESEL


GAS




NG


LPG










(a)


The low fuel level considered for such a disablement shall not exceed 100 litres or 20 per cent of the nominal capacity of the fuel tank, whichever is lower.






X


 


X










(b)


The low fuel pressure in the tank considered for such a disablement shall not exceed 20 per cent of the nominal fuel pressure in the tank






 


X’


 









Add a new paragraph 5.2.8, to read:







‘5.2.8.


Re-fuelling
After a refuelling, the manufacturer of a gaseous-fuelled vehicle may temporarily disable the OBD system when the system has to adapt to the recognition by the ECU of a change in the fuel quality and composition.
The OBD system shall be re-enabled as soon as the new fuel is recognised and the engine parameters are readjusted. This disablement shall be limited to a maximum of 10 minutes.’
               





Paragraph 6, amend to read (adding a new subparagraph (d)):







‘6.


DEMONSTRATION REQUIREMENTS
…






(d)


procedure for selecting the reference fuel in case of a gas engine’









Paragraph 6.3, amend to read:







‘6.3.


Procedures for demonstrating the OBD performance
The manufacturer shall …
In the following paragraphs the requirements for demonstrating the OBD performance are listed, including requirements for testing. The number of tests shall be four times the number of engine families considered within the emission OBD family, but shall not be less than 8.
The monitors selected shall reflect the different types of monitors mentioned in paragraph 4.2 (i.e. emission threshold monitoring, performance monitoring, total functional failure monitoring, or component monitoring) in a well balanced manner. The monitors selected shall also reflect the different items listed in Appendix 3 of this Annex in a well balanced manner.’
               





Paragraph 6.3.2, amend to read (correcting also footnote 10):







‘6.3.2.


Procedures for qualifying a deteriorated component (or system)
This paragraph applies to the cases where the malfunction selected for an OBD demonstration test is monitored against tailpipe emissions (10) (emission threshold monitoring — see paragraph 4.2) and it is required that the manufacturer demonstrates, by an emission test, the qualification of that deteriorated component.





Insert a new paragraph 6.5, to read:







‘6.5.


Procedure for selecting the reference fuel in case of a gas engine
Demonstration of the OBD performance and malfunction classification shall be performed by using one of the reference fuels mentioned in Annex 5 on which the engine is designed to operate.
The selection of this reference fuel is done by the type approval authority, who shall provide sufficient time for the test laboratory to supply the selected reference fuel.’
               





Paragraph 7.2, amend to read:







‘7.2.


Applicable tests
In the context of this Annex:






(a)


the emission test-cycle is the test-cycle used for the measurement of the regulated emissions when qualifying a deteriorated component or system,










(b)


the OBD test-cycle is the test-cycle used to demonstrate the capacity of the OBD monitors to detect malfunctions.’









Paragraph 7.2.2, amend to read (deleting the word ‘Word-wide harmonised’):







‘7.2.2.


OBD test cycle
The OBD test-cycle considered in this Annex is the hot part of the WHTC cycle as described in Annex 4B.
On request of the manufacturer and after approval of the type approval authority, an alternative OBD test-cycle can be used (e.g. the cold part of the WHTC cycle) for a specific monitor. The request shall contain documentation (technical considerations, simulation, test results, etc.) showing that:






(a)


the requested test-cycle appropriate to demonstrate monitoring occurs under real world driving conditions, and,










(b)


the hot part of the WHTC cycle appears as less appropriate for the considered monitoring (e.g. fluid consumption monitoring).’









Paragraph 8.1.3, correct to read:







‘8.1.3.


Documentation associated with the emission-OBD family
…
In addition, the manufacturer shall provide a list of all electronic input, output and identification of the communication protocol utilised by each emission-OBD family.’
               





Annex 9B, Appendix 2, correct the first paragraph to read:


               ‘This appendix aims at illustrating the requirements set in paragraphs 4.3 and 4.6.5 of this Annex.’
            

Annex 9B, Appendix 3, amend to read (inserting also a new item 15):


                        ‘MONITORING REQUIREMENTS
The items of this appendix list the systems or components required to be monitored by the OBD system, according to paragraph 4.2. Unless specified otherwise, the requirements apply to both diesel and gas engines.
ITEM 1
ELECTRIC / ELECTRONIC COMPONENTS MONITORING
Electric/electronic components used to control or monitor the emission control systems described in this appendix shall be subject to Component Monitoring according to the provisions of paragraph 4.2 of this Annex. This includes, but is not limited to, pressure sensors, temperature sensors, exhaust gas sensors and oxygen sensors when present, knock sensors, in-exhaust fuel or reagent injector(s), in-exhaust burners or heating elements, glow plugs, intake air heaters.
Wherever a feedback control loop exists, the OBD system shall monitor the system's ability to maintain feedback control as designed (e.g. to enter feedback control within a manufacturer specified time interval, system fails to maintain feedback control, feedback control has used up all the adjustment allowed by the manufacturer) — component monitoring.
Note: These provisions apply to all electric-electronic components, even if they belong to any of the monitors described in the other items of this appendix.
ITEM 2
DPF SYSTEM
The OBD system shall monitor the following elements of the DPF system on engines so-equipped for proper operation:






(a)


DPF substrate: the presence of the DPF substrate — total functional failure monitoring










(b)


DPF performance: clogging of the DPF — total functional failure










(c)


DPF performance: filtering and regeneration processes (e.g. particulate accumulation during the filtering process and particulate removal during a forced regeneration process) — performance monitoring (for example, evaluation of measurable DPF properties such as backpressure or differential pressure, which may not detect all failure modes that reduce trapping efficiency).




ITEM 3
SELECTIVE CATALYTIC REDUCTION (SCR) MONITORING
For the purpose of this Item, SCR means selective catalytic reduction or other lean NOx catalyst device. The OBD system shall monitor the following elements of the SCR system on engines so-equipped for proper operation:






(a)


Active/intrusive reagent injection system: the system's ability to regulate reagent delivery properly, whether delivered via an in-exhaust injection or an in-cylinder injection — performance monitoring.










(b)


Active/intrusive reagent: the on-board availability of the reagent, the proper consumption of the reagent if a reagent other than fuel is used (e.g. urea) — performance monitoring.










(c)


Active/intrusive reagent: to the extent feasible the quality of the reagent if a reagent other than fuel is used (e.g. urea) — performance monitoring.










(d)


SCR catalyst conversion efficiency: the catalyst's SCR ability to convert NOx — emission threshold monitoring.




ITEM 4
LEAN-NOX TRAP (LNT, OR NOX ADSORBER)
The OBD system shall monitor the following elements of the LNT system on engines so-equipped for proper operation:






(a)


LNT capability: the LNT system’s ability to adsorb/store and convert NOx — performance monitoring.










(b)


LNT active/intrusive reagent injection system: the system’s ability to regulate reagent delivery properly, whether delivered via an in-exhaust injection or an in-cylinder injection — performance monitoring.




ITEM 5
OXIDATION CATALYSTS (INCL. DIESEL OXIDATION CATALYST — DOC) MONITORING
This item applies to oxidation catalysts that are separate from other after-treatment systems. Those that are included in the canning of an after-treatment system are covered within the appropriate item of this appendix.
The OBD system shall monitor the following elements of the oxidation catalysts on engines so-equipped for proper operation:






(a)


HC conversion efficiency: the oxidation catalysts ability to convert HC upstream of other after-treatment devices — total functional failure monitoring.










(b)


HC conversion efficiency: the oxidation catalysts ability to convert HC downstream of other after-treatment devices — total functional failure monitoring.




ITEM 6
EXHAUST GAS RECIRCULATION (EGR) SYSTEM MONITORING
The OBD system shall monitor the following elements of the EGR system on engines so-equipped for proper operation:







 


DIESEL


GAS










(a1)


EGR low/high flow: the EGR system’s ability to maintain the commanded EGR flow rate, detecting both “flow rate too low” and “flow rate too high” conditions – emission threshold monitoring.






X


 










(a2)


EGR low/high flow: the EGR system’s ability to maintain the commanded EGR flow rate, detecting both “flow rate too low” and “flow rate too high” conditions — performance monitoring.
(monitoring requirement to be further discussed)






 


X










(b)


Slow response of the EGR actuator: the EGR system’s ability to achieve the commanded flow rate within a manufacturer specified time interval following the command — performance monitoring.






X


X










(c)


EGR cooler under cooling performance: the EGR cooler system’s ability to achieve the manufacturer’s specified cooling performance — performance monitoring.






X


X




ITEM 7
FUEL SYSTEM MONITORING
The OBD system shall monitor the following elements of the fuel system on engines so-equipped for proper operation:







 


DIESEL


GAS










(a)


Fuel system pressure control: fuel system ability to achieve the commanded fuel pressure in closed loop control — performance monitoring.






X


 










(b)


Fuel system pressure control: fuel system ability to achieve the commanded fuel pressure in closed loop control in the case where the system is so constructed that the pressure can be controlled independently of other parameters — performance monitoring.






X


 










(c)


Fuel injection timing: fuel system ability to achieve the commanded fuel timing for at least one of the injection events when the engine is equipped with the appropriate sensors — performance monitoring.






X


 










(d)


Fuel injection system: ability to maintain the desired air-fuel ratio (incl. but not limited to self adaptation features) — performance monitoring.






 


X




ITEM 8
AIR HANDLING AND TURBOCHARGER/BOOST PRESSURE CONTROL SYSTEM
The OBD system shall monitor the following elements of the Air Handling and Turbocharger/Boost Pressure Control System on engines so-equipped for proper operation:







 


DIESEL


GAS










(a1)


Turbo under/over boost: turbo boost system’s ability to maintain the commanded boost pressure, detecting both “boost pressure too low” and “boost pressure too high” conditions — emission threshold monitoring.






X


 










(a2)


Turbo under/over boost: turbo boost system’s ability to maintain the commanded boost pressure, detecting both “boost pressure too low” and “boost pressure too high” conditions — performance monitoring
(monitoring requirement to be further discussed).






 


X










(b)


Variable geometry turbo (VGT) slow response: VGT system’s ability to achieve the commanded geometry within a manufacturer specified time-performance monitoring.






X


X










(c)


Charge air cooling: Charge air cooling system efficiency — total functional failure.






X


X




ITEM 9
VARIABLE VALVE TIMING (VVT) SYSTEM
The OBD system shall monitor the following elements of the Variable Valve Timing (VVT) System on engines so-equipped for proper operation:






(a)


VVT target error: VVT system’s ability to achieve the commanded valve timing — performance monitoring.










(b)


VVT slow response: VVT system’s ability to achieve the commanded valve timing within a manufacturer specified time interval following the command-performance monitoring.




ITEM 10
MISFIRE MONITORING







 


DIESEL


GAS










(a)


No prescriptions.






X


 










(b)


Misfire that may cause catalyst damage (e.g. by monitoring a certain percentage of misfiring in a certain period of time) — performance monitoring
(monitoring requirement to be further discussed together with items 6 and 8).






 


X




ITEM 11
CRANKCASE VENTILATION SYSTEM MONITORING
No prescriptions.
ITEM 12
ENGINE COOLING SYSTEM MONITORING
The OBD system shall monitor the following elements of the engine cooling system for proper operation:






(a)


Engine coolant temperature (thermostat): Stuck open thermostat. Manufacturers need not monitor the thermostat if its failure will not disable any other OBD monitors — total functional failure.




Manufacturers need not monitor the engine coolant temperature or the engine coolant temperature sensor if the engine coolant temperature or the engine coolant temperature sensor is not used to enable closed-loop/feedback control of any emissions control systems and/or will not disable any other monitor.
Manufacturers may suspend or delay the monitor for the time to reach close loop to enable temperature if the engine is subjected to conditions that could lead to false diagnosis (e.g. vehicle operation at idle for more than 50 to 75 per cent of the warm-up time).
ITEM 13
EXHAUST GAS AND OXYGEN SENSORS MONITORING
The OBD system shall monitor:







 


DIESEL


GAS










(a)


the electrical elements of the exhaust gas sensors on engines so-equipped for proper operation according to item 1 to this appendix — component monitoring.






X


X










(b)


both the Primary and Secondary (fuel control) oxygen sensors. These sensors are considered as exhaust gas sensors to be monitored for proper operation according to item 1 to this appendix — component monitoring.






 


X




ITEM 14
IDLE SPEED CONTROL SYSTEM MONITORING
The OBD system shall monitor the electrical elements of the idle speed control systems on engines so-equipped for proper operation according to item 1 to this appendix.
ITEM 15
THREE-WAY CATALYST
The OBD system shall monitor the three-way catalyst on engines so-equipped for proper operation:







 


DIESEL


GAS










(a)


Three-way Catalyst Conversion efficiency: the catalyst ability to convert NOx and CO — performance monitoring.






 


X’





Annex 9B, Appendix 4, amend to read:


                        ‘Technical compliance report
This report …
FINAL COMPLIANCE REPORT
The documentation package and the herewith described OBD system / emission OBD family comply with the requirements of the following regulation:
Regulation … / version … / enforcement date …. / type of fuel …
…’
                  

Annex 9B, Appendix 4, item 4, paragraph 1.1, the table, line ‘Test information’, amend ‘Testing fuel’ to read ‘Reference fuel’.
Annex 9B, Appendix 5, table 3, amend to read:

‘Table 3
Optional information, if used by the emission or the OBD system to enable or disable any OBD information







 


Freeze frame


Data stream




Fuel level or tank fuel pressure (as appropriate)


X


X




Engine oil temperature


X


X




Vehicle speed


X


X




Status of the fuel quality adaptation (active / not active) in case of gas engines


 


X




Engine control computer system voltage (for the main control chip)


X


X’





Annex 9B, Appendix 5, table 4, amend to read:

‘Table 4
Optional information, if the engine is so equipped, senses or calculates the information







 


Freeze frame


Data stream




Absolute throttle position …


X


X




…


 


 




Oxygen sensor output


 


X




Secondary Oxygen sensor output (when fitted)


 


X




NOx sensor output


 


X’





Insert a new Annex 9C, to read:



‘ANNEX 9C
Technical requirements for assessing the in-use performance of on-board diagnostic systems (OBD)
1.   APPLICABILITY
In its current version, this Annex is only applicable to road-vehicles equipped with a Diesel engine
2.   (Reserved)
3.   DEFINITIONS
3.1.   “In-Use performance ratio”
The in-use performance ratio (IUPR) of a specific monitor m of the OBD system is: IUPRm = Numeratorm / Denominatorm

3.2.   “Numerator”
The numerator of a specific monitor m (Numeratorm) is a counter indicating the number of times a vehicle has been operated such that all monitoring conditions necessary for that specific monitor to detect a malfunction have been encountered.
3.3.   “Denominator”
The denominator of a specific monitor m (Denominatorm) is a counter indicating the number of vehicle driving events, taking into account conditions specific to that specific monitor.
3.4.   “General Denominator”
The general denominator is a counter indicating the number of times a vehicle has been operated, taking into account general conditions.
3.5.   “Ignition cycle counter”
The ignition cycle counter is a counter indicating the number of engine starts a vehicle has experienced.
3.6.   “Engine start”
An engine start consists of ignition-On, cranking and start of combustion, and is completed when the engine speed reaches 150 min–1 below the normal, warmed-up idle speed.
3.7.   “Driving cycle”
A driving cycle means a sequence consisting of an engine start, an operating period, an engine shut-off, and the time until the next engine start.
3.8.   Abbreviations






IUPR


In-Use Performance Ratio




IUPRm



In-Use Performance Ratio of a specific monitor m




4.   GENERAL REQUIREMENTS
The OBD system shall have the capability of tracking and recording in-use performance data (paragraph 6) of the OBD monitors specified in this paragraph, of storing these data in computer memory and communicating them off-board upon request (paragraph 7).
The in-use performance data of a monitor consists of the numerator and denominator enabling the calculation of the IUPR.
4.1.   IUPR monitors
4.1.1.   Groups of monitors
Manufacturers shall implement software algorithms in the OBD system to individually track and report in-use performance data of the groups of monitors mentioned in Appendix 1 of this Annex.
Manufacturers are not required to implement software algorithms in the OBD system to individually track and report in-use performance data of monitors running continuously as defined in paragraph 4.2.3 of Annex 9B if these monitors are already part of one of the groups of monitors mentioned in Appendix 1 of this Annex.
In-use performance data of monitors associated to different exhaust lines or engine banks within a group of monitors shall be tracked and recorded separately as specified in paragraph 6 and reported as specified in paragraph 7.
4.1.2.   Multiple monitors
For each group of monitors which are required to be reported by paragraph 4.1.1, the OBD system shall separately track in-use performance data, as specified in paragraph 6, for each of the specific monitors belonging to that group.
4.2.   Limitation of the use of in-use performance data
In-use performance data of a single vehicle are used for the statistical evaluation of the in-use performance of the OBD system of a larger group of vehicles.
Contrary to other OBD data, in-use performance data cannot be used to draw conclusions concerning the road-worthiness of an individual vehicle.
5.   REQUIREMENTS FOR CALCULATING IN-USE PERFORMANCE RATIOS
5.1.   Calculation of the in-use performance ratio
For each monitor m considered in the present annex, the in-use performance ratio is calculated with the following formula:
IUPRm = Numeratorm / Denominatorm

where the Numeratorm and Denominatorm are incremented according to the specifications of this paragraph.
5.1.1.   Requirements for the ratio when calculated and stored by system
Each IUPRm ratio shall have a minimum value of zero and a maximum value of 7,99527 with a resolution of 0,000122 (7).
A ratio for a specific component shall be considered to be zero whenever the corresponding numerator is equal to zero and the corresponding denominator is not zero.
A ratio for a specific component shall be considered to be the maximum value of 7,99527 if the corresponding denominator is zero or if the actual value of the numerator divided by the denominator exceeds the maximum value of 7,99527.
5.2.   Requirements for incrementing the numerator
The numerator shall not be incremented more than once per driving cycle.
The numerator for a specific monitor shall be incremented within 10 seconds if and only if the following criteria are satisfied on a single driving cycle:






(a)


Every monitoring condition necessary for the monitor of the specific component to detect a malfunction and store a potential DTC has been satisfied, including enable criteria, presence or absence of related DTCs, sufficient length of monitoring time, and diagnostic executive priority assignments (e.g. diagnostic “A” shall execute prior to diagnostic “B”).
Note: For the purpose of incrementing the numerator of a specific monitor, it may not be sufficient to satisfy all the monitoring conditions necessary for that monitor to determine the absence of a malfunction.










(b)


For monitors that require multiple stages or events in a single driving cycle to detect a malfunction, every monitoring condition necessary for all events to have been completed shall be satisfied.










(c)


For monitors which are used for failure identification and that run only after a potential DTC has been stored, the numerator and denominator shall be the same as those of the monitor detecting the original malfunction.










(d)


For monitors that require an intrusive operation to further investigate the presence of a malfunction, the manufacturer may submit to the type approval authority an alternative way to increment the numerator. This alternative should be equivalent to that which would, had a malfunction been present, have permitted to increment the numerator.




For monitors that run or complete during engine-off operation, the numerator shall be incremented within 10 seconds after the monitor has completed during engine-off operation or during the first 10 seconds of engine start on the subsequent driving cycle.
5.3.   Requirements for incrementing the denominator
5.3.1.   General incrementing rules
The denominator shall be incremented once per driving cycle, if during this driving cycle






(a)


the general denominator is incremented as specified in paragraph 5.4, and










(b)


the denominator is not disabled according to paragraph 5.6, and










(c)


when applicable, the specific additional incrementing rules specified in paragraph 5.3.2 are met.




5.3.2.   Additional monitor specific incrementing rules
5.3.2.1.   Specific denominator for evaporative system (reserved)
5.3.2.2.   Specific denominator for secondary air systems (reserved)
5.3.2.3.   Specific denominator for components/systems that operate at engine start-up only
In addition to the requirements of paragraph 5.3.1(a) and (b), the denominator(s) for monitors of components or systems that operate only at engine start-up shall be incremented if the component or strategy is commanded “on” for a time greater than or equal to 10 seconds.
For purposes of determining this commanded “on” time, the OBD system may not include time during intrusive operation of any of the components or strategies later in the same driving cycle solely for the purposes of monitoring.
5.3.2.4.   Specific denominator for components or systems that are not continuously commanded to function
In addition to the requirements of paragraph 5.3.1(a) and (b), the denominator(s) for monitors of components or systems that are not continuously commanded to function (e.g. Variable Valve Timing systems — VVT- or EGR valves), shall be incremented if that component or system is commanded to function (e.g. commanded “on”, “open”, “closed”, “locked”) on two or more occasions during the driving cycle, or for a cumulative time greater than or equal to 10 seconds, whichever occurs first.
5.3.2.5.   Specific denominator for DPF
In addition to the requirements of paragraph 5.3.1(a) and (b), in at least one driving cycle the denominator(s) for DPF shall be incremented if at least 800 cumulative kilometres of vehicle operation or alternatively at least 750 minutes of engine run time have been experienced since the last time the denominator was incremented.
5.3.2.6.   Specific denominator for oxidation catalysts
In addition to the requirements of paragraph 5.3.1(a) and (b), in at least one driving cycle the denominator(s) for monitors of oxidation catalyst used for the purpose of DPF active regeneration shall be incremented if a regeneration event is commanded for a time greater than or equal to 10 seconds.
5.3.2.7.   Specific denominator for hybrids (reserved)
5.4.   Requirements for incrementing the general denominator
The general denominator shall be incremented within 10 seconds, if and only if, all the following criteria are satisfied on a single driving cycle:






(a)


Cumulative time since start of driving cycle is greater than or equal to 600 seconds while remaining:






(i)


at an elevation of less than 2 500 meters above sea level; and










(ii)


at an ambient temperature of greater than or equal to 266 K (–7 degrees Celsius); and










(iii)


at an ambient temperature of lower than or equal to 308 K (35 degrees Celsius).














(b)


Cumulative engine operation at or above 1 150 min–1 for greater than or equal to 300 seconds while under the conditions specified in the above subparagraph (a); as alternatives left to the manufacturer an engine operation at or above 15 per cent calculated load or a vehicle operation at or above 40 km/h may be used in lieu of the 1 150 min–1 criterion.










(c)


Continuous vehicle operation at idle (e.g. accelerator pedal released by driver and either vehicle speed less than or equal to 1,6 km/h or engine speed less than or equal to 200 min–1 above normal warmed-up idle) for greater than or equal to 30 seconds while under the conditions specified in the above subparagraph (a).




5.5.   Requirements for incrementing the ignition cycle counter
The ignition cycle counter shall be incremented once and only once per engine start.
5.6.   Incrementing disablement of the numerators, of the denominators and of the general denominator
5.6.1.   Within 10 seconds of a malfunction being detected (i.e. a potential or a confirmed and active DTC is stored), which disables a monitor, the OBD system shall disable further incrementing of the corresponding numerator and denominator for each monitor that is disabled.
When the malfunction is no longer detected (e.g. the potential DTC is erased through self-clearing or through a scan-tool command), incrementing of all corresponding numerators and denominators shall resume within 10 seconds.
5.6.2.   Within 10 seconds of the start of operation of a Power Take-Off unit (PTO) that disables a monitor as permitted in paragraph 5.2.5 of Annex 9B, the OBD system shall disable further incrementing of the corresponding numerator and denominator for each monitor that is disabled.
When the PTO operation ends, incrementing of all corresponding numerators and denominators shall resume within 10 seconds.
5.6.3.   In the case of a malfunction (i.e. a potential or confirmed and active DTC has been stored) preventing determination of whether the criteria for the Denominatorm of a monitor m mentioned in paragraph 5.3 are satisfied (8), the OBD system shall disable further incrementing the Numeratorm and Denominatorm within 10 seconds.
Incrementing the Numeratorm and Denominatorm shall resume within 10 seconds when the malfunction is no longer present (e.g. pending code erased through self-clearing or by a scan tool command).
5.6.4.   In the case of a malfunction (i.e. a potential or confirmed and active DTC has been stored) preventing determination of whether the criteria for the General denominator mentioned in paragraph 5.4 are satisfied (9), the OBD system shall disable further incrementing the general denominator within 10 seconds.
Incrementing the general denominator shall resume within 10 seconds when the malfunction is no longer present (e.g. pending code erased through self-clearing or by a scan tool command).
The general denominator may not be disabled from incrementing for any other condition.
6.   REQUIREMENTS FOR TRACKING AND RECORDING IN-USE PERFORMANCE DATA
For each group of monitors listed in Appendix 1 to this Annex, the OBD system shall separately track numerators and denominators for each of the specific monitors listed in Appendix 3 of Annex 9B and belonging to that group.
It shall report only the corresponding numerator and denominator for the specific monitor that has the lowest numerical ratio.
If two or more specific monitors have identical ratios, the corresponding numerator and denominator for the specific monitor that has the highest denominator shall be reported for the specific group of monitors.
In order to determine without bias the lowest ratio of a group, only the monitors specifically mentioned in that group shall be taken into consideration (e.g. a NOx sensor when used to perform one of the monitors listed in Annex 9B, Appendix 3, item 3 “SCR” will be taken into consideration into the “exhaust gas sensor” group of monitors and not in the “SCR” group of monitors).
The OBD system shall also track and report the general denominator and the ignition cycle counter.
Note: according to paragraph 4.1.1, manufacturers are not required to implement software algorithms in the OBD system to individually track and report numerators and denominators of monitors running continuously.
7.   REQUIREMENTS FOR STORING AND COMMUNICATING IN-USE PERFORMANCE DATA
Communication of the in-use performance data is a new use-case and is not included in the three existing use-cases which are dedicated to the presence of possible malfunctions
7.1.   Information about in-use performance data
The information about in-use performance data recorded by the OBD system shall be available upon off-board request according to paragraph 7.2.
This information will provide type approval authorities with in use performance data.
The OBD system shall provide all information (according to the applicable standard set in Appendix 6) for the external IUPR test equipment to assimilate the data and provide an inspector with the following information:






(a)


the VIN (vehicle identification number);










(b)


the numerator and denominator for each group of monitors recorded by the system according to paragraph 6;










(c)


the general denominator;










(d)


the value of the ignition cycle counter;










(e)


the total engine running hours.




This information shall be available through “read-only” access (i.e. no clearing).
7.2.   Access to in-use performance data
Access to in-use performance data shall be provided only in accordance with the standards mentioned in Appendix 6 of Annex 9B and the following sub-paragraphs (10).
Access to the in-use performance data shall not be dependent on any access code or other device or method obtainable only from the manufacturer or its suppliers. Interpretation of the in-use performance data shall not require any unique decoding information, unless that information is publicly available.
The access method (i.e. the access point/node) to in-use performance data shall be the same as the one used to retrieve all OBD information. This method shall permit access to the complete in-use performance data required by this Annex.
7.3.   Reinitialising in-use performance data
7.3.1.   Reset to zero
Each number shall be reset to zero only when a non-volatile random access memory (NVRAM) reset occurs (e.g. reprogramming event). Numbers may not be reset to zero under any other circumstances including when a scan tool command to clear fault codes is received.
7.3.2.   Reset in case of memory overflow
If either the numerator or denominator for a specific monitor reaches 65 535 ± 2, both numbers shall be divided by two before either is incremented again to avoid overflow problems.
If the ignition cycle counter reaches the maximum value of 65 535 ± 2, the ignition cycle counter may rollover and increment to zero on the next ignition cycle to avoid overflow problems.
If the general denominator reaches the maximum value of 65 535 ± 2, the general denominator may rollover and increment to zero on the next driving cycle that meets the general denominator definition to avoid overflow problems.




‘APPENDIX 1
GROUPS OF MONITORS
The groups of monitors considered in this Annex are the following:






A.


Oxidation catalysts
The monitors specific to that group are those listed in item 5 of Appendix 3 to Annex 9B.










B.


Selective Catalytical Reduction systems (SCR)
The monitors specific to that group are those listed in item 3 of Appendix 3 to Annex 9B.










C.


Exhaust gas and oxygen sensors
The monitors specific to that group are those listed in item 13 of Appendix 3 to Annex 9B.










D.


EGR systems and VVT
The monitors specific to that group are those listed in items 6 and 9 and of Appendix 3 to Annex 9B.










E.


DPF systems
The monitors specific to that group are those listed in item 2 of Appendix 3 to Annex 9B.










F.


Boost pressure control system
The monitors specific to that group are those listed in item 8 of Appendix 3 to Annex 9B.










G.


NOx adsorber
The monitors specific to that group are those listed in item 4 of Appendix 3 to Annex 9B.










H.


Three-way catalyst
The monitors specific to that group are those listed in item 15 of Appendix 3 to Annex 9B.










I.


Evaporative systems (reserved)










J.


Secondary Air system (reserved)




A specific monitor shall belong only to one of these groups.



Insert a new Annex 10, to read:




                        ‘ANNEX 10
TECHNICAL REQUIREMENTS ON OFF-CYCLE EMISSIONS (OCE)
1.   APPLICABILITY
This annex establishes performance-based off-cycle emission requirements and a prohibition on defeat strategies for heavy-duty engines and vehicles so as to achieve effective control of emissions under a broad range of engine and ambient operating conditions encountered during normal in-use vehicle operation.
2.   Reserved (11)

3.   DEFINITIONS
3.1.   
                           “Auxiliary Emission Strategy” (AES) means an emission strategy that becomes active and replaces or modifies a base emission strategy for a specific purpose or purposes and in response to a specific set of ambient and/or operating conditions and only remains operational as long as those conditions exist.
3.2.   
                           “Base Emission Strategy” (BES) means an emission strategy that is active throughout the speed and load operating range of the engine unless an AES is activated.
3.3.   
                           “Defeat strategy” means an emission strategy that does not meet the performance requirements for a base and/or auxiliary emission strategy as specified in this Annex.
3.4.   
                           “Element of design” means:






(a)


the engine system;










(b)


any control system, including: computer software; electronic control systems; and computer logic;










(c)


any control system calibration; or










(d)


the results of any interaction of systems.




3.5.   
                           “Emission strategy” means an element or set of elements of design that is incorporated into the overall design of an engine system or vehicle and used in controlling emissions.
3.6.   
                           “Emission control system” means the elements of design and emission strategies developed or calibrated for the purpose of controlling emissions.
3.7.   
                           “Engine family” means a manufacturer's grouping of engines as defined in gtr No 4 (12).
3.8.   
                           “Engine starting” means the process from the initiation of engine cranking until the engine reaches a speed 150 min–1 below the normal, warmed up idle speed (as determined in the drive position for vehicles equipped with an automatic transmission).
3.9.   
                           “Engine system” means the engine, the emission control system and the communication interface (hardware and messages) between the engine electronic control unit(s) and any other powertrain or vehicle control unit.
3.10.   
                           “Engine warm-up” means sufficient vehicle operation such that the coolant temperature reaches a minimum temperature of at least 70 °C.
3.11.   
                           “Periodic regeneration” means the regeneration process of an exhaust after-treatment system that occurs periodically in typically less than 100 hours of normal engine operation.
3.12.   
                           “Rated speed” means the maximum full load speed allowed by the governor as specified by the manufacturer in his sales and service literature, or, if such a governor is not present, the speed at which the maximum power is obtained from the engine, as specified by the manufacturer in his sales and service literature.
3.13.   
                           “Regulated emissions” means “gaseous pollutants” defined as carbon monoxide, hydrocarbons and/or non-methane hydrocarbons (assuming a ratio of CH1,85 for diesel, CH2,525 for LPG and CH2,93 for NG, and an assumed molecule CH3O0,5 for ethanol fuelled diesel engines), methane (assuming a ration of CH4 for NG) and oxides of nitrogen (expressed in nitrogen dioxide (NO2) equivalent) and “particulate matter” (PM) defined as any material collected on a specified filter medium after diluting exhaust with clean filtered air to a temperature between 315 K (42 °C) and 325 K (52 °C), as measured at a point immediately upstream of the filter, this is primarily carbon, condensed hydrocarbons, and sulphates with associated water.
4.   GENERAL REQUIREMENTS
Any engine system and any element of design liable to affect the emission of regulated pollutants shall be designed, constructed, assembled and installed so as to enable the engine and vehicle to comply with the provisions of this Annex.
4.1.   Prohibition of defeat strategies
Engine systems and vehicles shall not be equipped with a defeat strategy.
4.2.   World-harmonised Not-To-Exceed emission requirement
This annex requires that engine systems and vehicles comply with the WNTE emission limit values described in paragraph 5.2. For laboratory based testing according to paragraph 7.4, no test result shall exceed the emissions limits specified in paragraph 5.2.
5.   PERFORMANCE REQUIREMENTS
5.1.   Emission strategies
Emission strategies shall be designed so as to enable the engine system, in normal use, to comply with the provisions of this Annex. Normal use is not restricted to the conditions of use as specified in paragraph 6.
5.1.1.   Requirements for Base Emission Strategies (BES)
A BES shall not discriminate between operation on an applicable type approval or certification test and other operation and provide a lesser level of emission control under conditions not substantially included in the applicable type approval or certification tests.
5.1.2.   Requirements for Auxiliary Emission Strategies (AES)
An AES shall not reduce the effectiveness of the emission control relative to a BES under conditions that may reasonably be expected to be encountered in normal vehicle operation and use, unless the AES satisfies one the following specific exceptions:






(a)


Its operation is substantially included in the applicable type approval or certification tests, including the WNTE provisions of paragraph 7;










(b)


It is activated for the purposes of protecting the engine and/or vehicle from damage or accident;










(c)


It is only activated during engine starting or warm up as defined in this Annex;










(d)


Its operation is used to trade-off the control of one type of regulated emissions in order to maintain control of another type of regulated emissions under specific ambient or operating conditions not substantially included in the type approval or certification tests. The overall affect of such an AES shall be to compensate for the effects of extreme ambient conditions in a manner that provides acceptable control of all regulated emissions.




5.2.   World-harmonised Not-To-Exceed limits for gaseous and particulate exhaust emissions
5.2.1.   Exhaust emissions shall not exceed the applicable WNTE emission limits specified in paragraph 5.2.2 when the engine is operated in accordance with the conditions and procedures set out in paragraphs 6 and 7.
5.2.2.   The applicable WNTE emission limits are determined, as follows:
WNTE Emission Limit = WHTC Emission Limit + WNTE Component
Where:






“WHTC Emission Limit”


is the emission limit (EL) to which the engine is certified pursuant to the WHDC gtr; and




“WNTE Component”


is determined by equations 1 to 4 in paragraph 5.2.3.




5.2.3.   The applicable WNTE components shall be determined using the following equations, when the ELs are expressed in g/kWh:







For NOx:


WNTE Component = 0,25 × EL + 0,1


(1)




For HC:


WNTE Component = 0,15 × EL + 0,07


(2)




For CO:


WNTE Component = 0,20 × EL + 0,2


(3)




For PM:


WNTE Component = 0,25 × EL + 0,003


(4)




Where the applicable ELs are expressed in units other than units of g/kWh, the additive constants in the equations shall be converted from g/kWh to the appropriate units.
The WNTE component shall be rounded to the number of places to the right of the decimal point indicated by the applicable EL in accordance with the rounding method of ASTM E 29-06.
6.   APPLICABLE AMBIENT AND OPERATING CONDITIONS
The WNTE emission limits shall apply at:






(a)


All atmospheric pressures greater than or equal to 82,5 kPa;










(b)


All temperatures less than or equal to the temperature determined by equation 5 at the specified atmospheric pressure:
T = –0,4514 × (101,3 – pb) + 311 (5)
Where:






T


is the ambient air temperature, K




pb



is the atmospheric pressure, kPa














(c)


All engine coolant temperature above 343 K (70 °C).




The applicable ambient atmospheric pressure and temperature conditions are shown in figure 1.
WNTE Atmospheric Pressure and Temperature Range




Figure 1


Illustration of atmospheric pressure and temperature conditions

Temperature (C)
Atmospheric Pressure (kPa)
WNTE Maximum Temperature
7.   WORLD-HARMONISED NOT-TO-EXCEED METHODOLOGY
7.1.   World-harmonised Not-To-Exceed control area
The WNTE control area consists of the engine speed and load points defined in paragraphs 7.1.1 through 7.1.6. Figure 2 is an example illustration of the WNTE control area.
7.1.1.   Engine speed range
The WNTE control area shall include all operating speeds between the 30th percentile cumulative speed distribution over the WHTC test cycle, including idle, (n30) and the highest speed where 70 per cent of the maximum power occurs (nhi). Figure 3 is an example of the WNTE cumulative speed frequency distribution for a specific engine.
7.1.2.   Engine torque range
The WNTE control area shall include all engine load points with a torque value greater than or equal to 30 per cent of the maximum torque value produced by the engine.
7.1.3.   Engine power range
Notwithstanding the provisions of paragraphs 7.1.1 and 7.1.2, speed and load points below 30 per cent of the maximum power value produced by the engine shall be excluded from the WNTE Control Area for all emissions.
7.1.4.   Application of engine family concept
In principal, any engine within a family with a unique torque/power curve will have its individual WNTE control area. For in-use testing, the individual WNTE control area of the respective engine shall apply. For type approval (certification) testing under the engine family concept of the WHDC gtr the manufacturer may optionally apply a single WNTE control area for the engine family under the following provisions:






(a)


A single engine speed range of the WNTE control area may be used; if the measured engine speeds n30 and nhi are within ±3 per cent of the engine speeds as declared by the manufacturer. If the tolerance is exceeded for any of the engine speeds, the measured engine speeds shall be used for determining the WNTE control area;










(b)


A single engine torque/power range of the WNTE control area may be used, if it covers the full range from the highest to the lowest rating of the family. Alternatively, grouping of engine ratings into different WNTE control areas is permitted.








Figure 2


Example WNTE control area

Engine Torque
WNTE Control Area
Engine Speed




Figure 3


Example of WNTE cumulative speed frequency distribution

Cumulative Frequency
Engine Speed
7.1.5.   Compliance exclusion from certain WNTE operating points
The manufacturer may request that the approval authority excludes operating points from the WNTE control area defined in paragraphs 7.1.1 through 7.1.4 during the certification/type approval. The approval authority may grant this exclusion if the manufacturer can demonstrate that the engine is never capable of operating at such points when used in any vehicle combination.
7.2.   Minimum World-harmonised Not-To-Exceed event duration and data sampling frequency
7.2.1.   To determine compliance with the WNTE emissions limits specified paragraph 5.2, the engine shall be operated within the WNTE control area defined in paragraph 7.1 and its emissions shall be measured and integrated over a minimum period of 30 seconds. A WNTE event is defined as a single set of integrated emissions over the period of time. For example, if the engine operates for 65 consecutive seconds within the WNTE control area and ambient conditions this would constitute a single WNTE event and the emissions would be averaged over the full 65 second period. In the case of laboratory testing, the integrating period of time of 7,5 seconds shall apply.
7.2.2.   For engines equipped with emission controls that include periodic regeneration events, if a regeneration event occurs during the WNTE test, then the averaging period shall be at least as long as the time between the events multiplied by the number of full regeneration events within the sampling period. This requirement only applies for engines that send an electronic signal indicating the start of the regeneration event.
7.2.3.   A WNTE event is a sequence of data collected at the frequency of at least 1 Hz during engine operation in the WNTE control area for the minimum event duration or longer. The measured emission data shall be averaged over the duration of each WNTE event.
7.3.   World-harmonised Not-To-Exceed in-use testing
Where the provisions of this Annex are used as basis for in-use testing, the engine shall be operated under actual in-use conditions. The test results out of the total data set that comply with the provisions of paragraphs 6, 7.1 and 7.2 shall be used for determining compliance with the WNTE emission limits specified in paragraph 5.2. It is understood that emission during some WNTE events may not be expected to comply with the WNTE emission limits. Therefore, statistical methods should be defined and implemented for determining compliance that are consistent with paragraphs 7.2 and 7.3.
7.4.   World-harmonised Not-To-Exceed laboratory testing
Where the provisions of this Annex are used as the basis for laboratory testing the following provision shall apply:
7.4.1.   The specific mass emissions of regulated pollutants shall be determined on the basis of randomly defined test points distributed across the WNTE control area. All the test points shall be contained within 3 randomly selected grid cells imposed over the control area. The grid shall comprise of 9 cells for engines with a rated speed less than 3 000 min–1 and 12 cells for engines with a rated speed greater than or equal to 3 000 min–1. The grids are defined as follows:






(a)


The outer boundaries of the grid are aligned to the WNTE control area;










(b)


2 vertical lines spaced at equal distance between engine speeds n30 and nhi for 9 cell grids, or 3 vertical lines spaced at equal distance between engine speeds n30 and nhi for 12 cell grids; and










(c)


2 lines spaced at equal distance of engine torque (1/2) at each vertical line within the WNTE control area.




Examples of the grids applied to specific engines are shown in Figures 5 and 6.
7.4.2.   The 3 selected grid cells shall each include 5 random test points, so a total of 15 random points shall be tested within the WNTE control area. Each cell shall be tested sequentially; therefore all 5 points in one grid cell are tested before transiting to the next grid cell. The test points are combined into a single ramped steady state cycle.
7.4.3.   The order in which each of the grid cells are tested, and the order of testing the points within the grid cell, shall be randomly determined. The 3 grid cells to be tested, the 15 test points, the order of testing the grid cells, and the order of the points within a grid cell shall be selected by the Type Approval or Certification Authority using acknowledged statistical methods of randomisation.
7.4.4.   The average specific mass emissions of regulated gaseous pollutants shall not exceed the WNTE limit values specified in paragraph 5.2 when measured over any of the cycles in a grid cell with 5 test points.
7.4.5.   The average specific mass emissions of regulated particulate pollutants shall not exceed the WNTE limit values specified in paragraph 5.2 when measured over the whole 15 test point cycle.
7.5.   Laboratory test procedure
7.5.1.   After completion of the WHSC cycle, the engine shall be preconditioned at mode 9 of the WHSC for a period of three minutes. The test sequence shall start immediately after completion of the preconditioning phase.
7.5.2.   The engine shall be operated for 2 minutes at each random test point. This time includes the preceding ramp from the previous steady state point. The transitions between the test points shall be linear for engine speed and load and shall last 20 ± 1 seconds.
7.5.3.   The total test time from start until finish shall be 30 minutes. The test of each set of 5 selected random points in a grid cell shall be 10 minutes, measured from the start of the entry ramp to the 1st point until the end of the steady state measurement at the 5th point. Figure 5 illustrates the sequence of the test procedure.
7.5.4.   The WNTE laboratory test shall meet the validation statistics of paragraph 7.7.2 of the WHDC gtr.
7.5.5.   The measurement of the emissions shall be carried out in accordance with paragraph 7.8 of WHDC gtr.
7.5.6.   The calculation of the test results shall be carried out in accordance with paragraph 8 of WHDC gtr.




Figure 4


Schematic example of the start of the WNTE test cycle

End of preconditioning (WHSC Mode 9)
Enter 1st cell
Point 1
Point 2
Point 3
Point 4
Exit 1st cell
Point 5
Enter 2nd cell
Point 6
20s max.
1 m 40s min.
2 minutes
10 minutes



Engine Rated Speed < 3000 rpm
WNTE Area
Engine Torque [N.m]
30 % Maximum Torque
n30
Engine Speed [rpm]
nHigh




Figures 5 and 6


WNTE test cycle grids

Engine Rated Speed ≥ 3000 rpm
WNTE Area
Engine Torque [N.m]
30 % Maximum Torque
n30
Engine Speed [rpm]
nHigh
7.6.   Rounding
Each final test result shall be rounded in one step to the number of places to the right of the decimal point indicated by the applicable WHDC emission standard plus one additional significant figure, in accordance with ASTM E 29-06. No rounding of intermediate values leading to the final brake specific emission result is permitted.
8.   WORLD-HARMONISED NOT-TO-EXCEED DEFICIENCIES
The concept of a deficiency is to allow an engine or vehicle to be certified as compliant with a regulation even though specific requirements, limited in scope, are not fully met. WNTE deficiency provision would allow a manufacturer to apply for relief from the WNTE emission requirements under limited conditions, such as extreme ambient temperatures and/or severe operation where vehicles do not accumulate significant mileage.
9.   WORLD-HARMONISED NOT-TO-EXCEED EXEMPTIONS
The concept of a WNTE exemption is a set of technical conditions under which the WNTE emission limits set out in this Annex would not apply. A WNTE exemption shall apply to all engine and vehicle manufacturers.
It may be decided to provide a WNTE exemption, in particular with the introduction of more stringent emission limits. For example a WNTE exemption may be necessary if the Approval Authority determines that certain engine or vehicle operation within the WNTE control area cannot achieve the WNTE emission limits. In such a case, the Approval Authority may determine that it is not necessary for engine manufacturers to request a WNTE deficiency for such operation, and that the granting of a WNTE exemption is appropriate. The Approval Authority can determine both the scope of the exemption with respect to the WNTE requirements, as well as the period of time for which the exemption is applicable.
10.   STATEMENT OF OFF-CYCLE EMISSION COMPLIANCE
In the application for certification or type approval, the manufacturer shall provide a statement that the engine family or vehicle complies with the requirements of this Annex. In addition to this statement, compliance with the WNTE limits shall be verified through additional tests and certification procedures defined by the Contracting Parties.
10.1.   Example statement of Off-Cycle Emission compliance
The following is an example compliance statement:

                           “(Name of manufacturer) attests that the engines within this engine family comply with all requirements of this Annex. (Name of manufacturer) makes this statement in good faith, after having performed an appropriate engineering evaluation of the emissions performance of the engines within the engine family over the applicable range of operating and ambient conditions.”
                        
10.2.   Basis for Off-Cycle Emission compliance statement
The manufacturer shall maintain records at the manufacturer’s facility which contain all test data, engineering analyses, and other information which provides the basis for the OCE compliance statement. The manufacturer shall provide such information to the Certification or Type Approval Authority upon request.
11.   DOCUMENTATION
The Approval Authority may decide to require that the manufacturer provides a documentation package. This should describe any element of design and emission control strategy of the engine system and the means by which it controls its output variables, whether that control is direct or indirect.
The information may include a full description of the emission control strategy. In addition, this could include information on the operation of all AES and BES, including a description of the parameters that are modified by any AES and the boundary conditions under which the AES operate, and indication of which AES and BES are likely to be active under the conditions of the test procedures in this Annex.’
                     





(1)  The numbering of this Annex is consistent with the numbering of the WHDC gtr. However, some sections of the WHDC gtr are not needed in this Annex.

(1)  depending on fuel.

(2)  atλ = 2, dry air, 273 K, 101,3 kPa.

(3)  
            u accurate within 0,2 % for mass composition of: C = 66 - 76 %; H = 22 - 25 %; N = 0 - 12 %.

(4)  NMHC on the basis of CH2,93 (for total HC the u
gas coefficient of CH4 shall be used).

(5)  
            u accurate within 0,2 % for mass composition of: C3 = 70 - 90 %; C4 = 10 - 30 %.

(6)  depending on fuel.

(7)  atλ = 2, dry air, 273 K, 101,3 kPa.

(8)  
            u accurate within 0,2 % for mass composition of: C = 66 - 76 %; H = 22 - 25 %; N = 0 - 12 %.

(9)  NMHC on the basis of CH2,93 (for total HC the u
gas coefficient of CH4 shall be used).

(10)  
            u accurate within 0,2 % for mass composition of: C3 = 70 - 90 %; C4 = 10 - 30 %.

(2)  The values quoted in the specification 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 statistical 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 question as to whether a fuel meets the requirements of the specifications, the terms of ISO 4259 should be applied.

(3)  Even though oxidation stability is controlled, it is likely that shelf life will be limited. Advice shall be sought from the supplier as to storage conditions and life.

(4)  Oxidation stability can be demonstrated by EN-ISO12205 or by EN 14112. This requirement shall be revised based on CEN/TC19 evaluations of oxidative stability performance and test limits.

(5)  FAME quality according EN 14214 (ASTM D 6751).

(6)  The latest version of the respective test method applies.

(7)  This value corresponds to a maximum hexadecimal value of 0xFFFF with a resolution of 0x1.

(8)  E.g. vehicle speed / engine speed / calculated load, ambient temperature, elevation, idle operation, or time of operation.

(9)  The manufacturer is allowed to use an additional on-board diagnostic display, such as a dashboard mounted video display device, for providing access to in-use performance data. Such an additional device is not subject to the requirements of this Annex.

(10)  The manufacturer is allowed to use an additional on-board diagnostic display, such as a dashboard mounted video display device, for providing access to in-use performance data. Such an additional device is not subject to the requirements of this Annex.

(11)  The numbering of this Annex is consistent with the numbering of the gtr on OCE. However, some paragraphs of the OCE gtr are not needed in this Annex.

(12)  Test Procedures for Compression-Ignition (CI) Engines and Positive-Ignition (PI) Engines Fuelled with Natural Gas (NG) or Liquefied Petroleum Gas (LPG) with regard to the Emission of Pollutants (established in the Global Registry on 15 November 2006). References to gtr No 4 relate to the document established on 15 November 2006. Later changes to the WHDC gtr will have to be revaluated as to their applicability to this Annex.