- 1 -  
 
 
  
 
National Standard  
of the People's Republic of China 
  
GB14621-200X 
Replacement of GB14621-2002 
 
 
 
Limits and measurement methods for exhaust 
pollutants from motorcycles and mopeds 
under two-speed idle conditions and simple 
transient driving mode conditions 
 
    
(Draft for approval) 
  
 
 
Issue Date: XX-XX-200X Impl ementation Date: XX-XX-2009 
 
 
Issued by the Ministry of Environmental Protection  
of the People's Republic of China 
General Administration of Quality Sup ervision, Inspection and Quarantine of 
the People's Republic of China  
 
- 2 -  
Contents 
 
Preface............................................................. 1 Scope............................................... 2 Normative references......................................... 3 Terms and definitions......................................... 4 Pollutants exhaust limits..................................... 5 Measurement methods........................................ 6 Single gaseous fuel vehicles  and dual-fuel vehicles................ 
7 Determination of measurement results....................................... 8 Implementation requirements..................................................... 9 Standard implementation........................................................... Appendix A (Informative annex) Recording Table for Pollutants in Two-speed Idle Mode Condition Appendix B (Normative annex) Measurement me thods for simple transient driving mode - 3 -  
Foreword 
This Standard is drawn up to implement the “Environmental Protection Law of the People's 
Republic of China” and the “Law of the People's Republic of China on th e Prevention and Control 
of Atmospheric Pollution”, to prevent and contro l environmental pollution from fuel evaporative 
pollutants from motorcycles and mopeds, and to improve the environmental air quality. 
This Standard defines the limits and measurement methods of evaporative po llutant emissions from 
motorcycles and mopeds under idle speed conditions and high idle speed conditions. It also specifies the measurement methods for simple tran sient driving mode conditions of motorcycles and 
mopeds. 
This Standard is a modification of the Limits and Measurement Methods for Exhaust Emissions 
from Motorcycles and Mopeds under Idle Speed (GB14621-2002). The modified  main contents are 
as below: 
− Added the exhaust limits and the measurem ent method under high idle speed conditions; 
− Added the measurement requirements for si mple transient driving mode conditions. 
 This Standard is the replacement for th e following standards: GB14621-1993, GB14621-2002. 
 Appendix A to this Standard is an informative anne x and Appendix B to this Standard is a normative 
annex.  This Standard was proposed and formulated by the Department of Science & Technology and Standards of the Ministry of Environmental Protection of the People's Republic of China. 
  The organisations responsible for th e drafting of this Standard are: 
Tianjin Motorcycle Technical Centre; 
The Chinese Research Academy of Environmental Sciences.  This Standard was approved by the Ministry of Environmental Protection on xx xx xxxx (date). 
 This Standard shall enter into force on xx xx xxxx (date).    The Ministry of Environmental Protection is resp onsible for the interpretation of this Standard. 
   - 4 -  
            
Limits and Measurement Methods for Exhaust Pollutants  
from Motorcycles and Mopeds unde r Two-speed Idle Conditions  
and Simple Transient Driving Mode Conditions 
 
 1  Scope 
This standard specifies the limits and meas urement methods for exhaust pollutants from 
motorcycles and mopeds under idle speed conditions and high idle speed conditions. It also specifies the measurement methods for simple tran sient driving mode conditions of motorcycles and 
mopeds.  This standard applies to the type-approval, insp ection for exhaust pollutant s from new and in-use 
motorcycles and mopeds with  positive-ign ition engines. 
 2  Normative References 
The provisions of the following documents will become provisions of this Standard after being 
referenced. The effective versions of the undate d references shall apply to this Standard. 
 GB 14622-2007 Limits and measurement methods for the emissions of pollutants from motorcycles 
on the running mode (China stage III) 
GB 17930-2006 Gasoline for motor vehicles GB 18047 Compressed natural gas as vehicle fuel GB 18176-2007 Limits and measurement methods for the emissions of pollutants from mopeds on 
the running mode (China stage III) 
GB 19159 Liquefied petroleum gas as vehicle fuel GB/T 5359.4 Terms for motorcycles and mopeds – Pa rt 4: Mass of vehicles with two and three 
wheels GB/T 5359.5 Terms for motorcycles and mopeds – Part 5: Mass of vehicles with two wheels 
GB/T 5359.6 Terms for motorcycles and mopeds – Pa rt 6: Mass of vehicles with three wheels 
GB/T 15089 Classification of power -driven vehicles and trailers 
HJ/T 3-1993 Gasoline-fuelled motor vehicles – Exhaust emissions analyser – Technical specialisation HJ/T 289-2006 Equipment specialisation and quality control requirements for gasoline vehicles in 
two-speed idle exhaust emission test HJ/T 290-2006 Equipment specialisation and qualit y control requirements for gasoline vehicles 
exhaust emission test in s hort transient loaded mode 
 
 3  Terms and definitions  
The terms and definitions listed below apply to this Standard. 
 3.1 Motorcycle 
Any two-wheeled motorcycle (Category L3), three- wheeled motorcycle with  a side car (Category 
L4) or motor tricycles (Categor y L5) as specified in GB/T 15089. - 5 -  3.2 Mopeds 
Any two-wheeled mopeds (Category L1) or three- wheeled moped (Category L2) as specified in 
GB/T 15089. 
 3.3 Exhaust pollutants 
The carbon monoxide (CO), hydrocarbon (HC) a nd nitrogen oxide (NOx) emitted by the gas 
exhaust pipes. 
 3.4 Mode conditions of idle speed and high idle speed   
The mode condition of idle speed is when the e ngine is in normal running with no-load and in a 
minimum steady running state, and the transmission is in neutral, the throttle  controller is at its 
minimum position, the choke valve is completely  open, and the rotation speed of the engine 
conforms to the specificati ons of the technical documen tation of the manufacturer. 
The mode condition of high idle speed is when  the above mentioned conditions are met (the 
position of the throttle controller is not included.  In respect of vehicles equipped with automatic 
transmissions, the driving wheels must be in a free state).To adjust the throttl e controller, control the 
rotation speed of the engi ne under the high idle rota ting speeds which are specified in the technical 
documentation of the manufacturer, but note that th e rotation speed under high idle speed must not 
be lower than 2000r/min. If this is not specified in the technical documents, then the rotation speed 
of the engine shall be controlled to be in the range of 2500r/min ± 250r/min. 
 
 3.5 V olume fraction of carbon monoxide (C O), hydrocarbon (HC) and carbon dioxide (CO 2) 
The volume fraction of the carbon monoxide (CO) is the volume percentage of the CO contained in 
the exhaust gases, presented as  a percentage. The volume fracti on of hydrocarbon (HC) is the 
volume percentage of the HC contained in  the exhausted gases, presented as 10-6; the volume 
fraction of the carbon dioxide (CO 2) is the volume pe rcentage of the CO 2 contained in the exhausted 
gases, presented as a percentage. 
 3.6 Gaseous fuel 
The natural gas (NG) specified in GB18047 or the liquefied petroleum gas (LPG) specified in GB 
19159. 
 3.7 Dual-fuel vehicles 
Motorcycles that can use both gasoline and ga seous fuel, but not both at the same time. 
 3.8 Single-gaseous fuel vehicles 
Motorcycles that only use one type of gaseous fuel or that can use one type of gaseous fuel (natural 
gas NG) or liquefied petroleum gas (LPG) and gasoline; however, gaso line is only used in 
emergency situations or only used  at start-up of motorcycles. 
 3.9 Reference mass (RM) 
The total mass of complete vehicl e kerb mass of any motorcycle specified in GB/T 5359.5 or GB/T 
5359.6 and the body mass of the vehicle driver.  - 6 -  3.10 Newly-produced vehicles 
Any motorcycle or moped before it has been a llocated number plates but has passed the final 
production line inspection of the manufacturer. 
 3.11  In-use vehicles 
Any motorcycle or moped which has been regi stered and has been allocated number plates. 
 4 Limits of exhaust pollutants 
 4.1 Type approval and exhaust pollutant limits of newly-produced vehicles 
The type approval and the exhaus t pollutant limits of any newl y-produced motorcycle and moped 
shall not exceed the limited values specified in Table 1.  Table 1 Type approval and the exhaust pollutant  limit of any newly-produced motorcycle and 
moped (volume fraction)  
Idle speed conditions Hi gh idle speed conditions 
Vehicle type and 
production dates CO 
% HCa 
10-6 CO 
% HCa 
10-6 
Type approval and 
new vehicles produced since xx xx 200x (date) 2 250 2 250 
HCa the volume fraction value of the HCa shall be according to the n-hexane equivalent values. 
 
 4.2 The limits of exhaust pollutants of in-use vehicles 
The exhaust pollutant limits of any in-use motorc ycle and moped shall not exceed the limited values 
specified in Table 2.  Table 2 The exhaust pollutant limit of in-use vehicles (volume fraction) 
Idle speed conditions Hi gh idle speed conditions 
Vehicle type and 
production dates CO 
% HCa 
10-6 CO 
% HCa 
10-6 
Motorcycles and 
mopeds (two-stroke) produced before 1 July 2003 4.5 8000 / / 
Motorcycles and 
mopeds (four-stroke) produced before 1 July 2003 4.5 2200 / / 
Motorcycles and 
mopeds (two-stroke) produced 4.5 4500 / / - 7 - since 1 July 2003 
Motorcycles and 
mopeds (four-stroke) produced since 1 July 2003 4.5 1200 / / 
Motorcycles and 
mopeds produced since 1 July 2010 
Motorcycles and mopeds  produced since 1 July 2011 3 400 3 400 
HCa the volume fraction value of the HCa shall be according to the n-hexane equivalent values. 
 
 5 Measurement methods 
 5.1 Measurement instruments 
The measurement instruments for ex haust pollutants shall conform to the regulations set out in HJ/T 
289-2006. Exhaust monitors that conform to HJ/T  3-1993 shall also apply to the exhaust 
measurement tests under idle speed conditions wh ich are specified in Table 2. The measurement 
results do not need to be amended at present. 
 5.2 Measurement procedures 
5.2.1 The preparation and use of the instruments 
The preparation (including pre-heating) and use of the instruments shall be carried out in 
accordance with the manual instructions  of the instrument manufacturers. 
5.2.2 Fuel and vehicle preparation 5.2.2.1 The fuels used for the type approval tests shall conform to the requirements set out in the 
Appendix F to the GB 14622-2007, the fuels used fo r the inspection tests of any new produced 
vehicle and in-use vehicle shall conform to the regul ations set out in the t echnical documents of the 
manufacturer. If the mixed lubricat ion method is applied to any engine, then the engine oil quantity 
and grade which are added to the fuel shall confor m to the regulations specified in the technical 
documents of the manufacturers. 
5.2.2.2 Vehicles must be in the normal state speci fied by the manufacturers; the exhaust system 
must not have any leaks. 
5.2.2.3 Vehicles shall be pre-heated  in accordance with the regulations set out  in the technical 
documents of the vehicle manufacturer s. In the case that  no regulati ons are set out in the technical 
documents, four circulations shall be conducted on the chassis dynamometer in accordance with the 
mode conditions specified in GB 14622-2007 for motorcycles and GB 18176-2007 for mopeds, or 
driving on a normal road for 15 minutes to carry out pre-heating. The meas urements of exhaust 
emissions at idle speed and high idle speed shall be carried out w ithin 10 minutes of the vehicle 
being pre-heated. 
5.2.2.4 Add a length of 600 mm with an inner diameter  of 40mm special sealed connecting tube to 
the rear part of the exhaust muffler, the exhaus t back pressure shall be ensured not to exceed - 8 - 1.25kPa, and will not affect the normal operating of the engine. 
5.2.2.5 In the case of multiple exhaust pipes, a Y-shape shall be used to connect the tube to collect 
the emissions into an identical tube for measurem ent, or measuring the em issions individually, and 
take the mean value of the measurement results of all exhaust pipes as the measurement result. 
5.2.3 Measurement of the exhaust polluta nts under high idle speed condition 
5.2.3.1 Engines accelerating from idle speed to 70% of its maximum net power rotation speed; after 
operating for 10 seconds, it is then  reduced to high idle speed. 
5.2.3.2 Maintain the high idle speed, insert a sample  probe into the connecting tube and ensure the 
inserting depth is not less than 400 mm. After ma intaining for approximately 15 seconds, read the 
mean value with a mean value functional instru ment within 30 seconds, or manually read the 
maximum value and minimum value within 30 seconds. The average value shall be the measurement result of the pollutants under high idle speed condition. 
5.2.4 Measurement of the exhaust pollutants at idle speed  When the condition of the engine from high idle sp eed reduced to idle speed and after maintaining 
for 15 seconds, read the mean value with a mean value functional instrument  within 30 seconds, or 
manually read the maximum value and minimum va lue within 30 seconds. The average value shall 
be the measurement result of the po llutants under idle speed condition. 
5.2.5 Recording of measurement result The rotation speed of the engine at  test, as well as the measurement of the volume fraction values of 
the carbon monoxide (CO), carbon dioxide (CO2) and hydrocarbon cont aining in the exhaust gases 
shall be recorded. 
5.2.6 Amendment of the measurement results The amended concentration of the carbon monoxide (C
CO modification ) shall be amended with the 
measurement values of the carbon monoxide (C CO) concentration an d carbon dioxide (C CO2) 
concentration in accordance with the following formula, the amended value shall be used as the measurement result. 
5.2.6.1 The amended concentration of the carbon monoxi de (CO) for two-stroke engines shall be: 
Cco modification =Cco×10
Cco×Cco2% 
5.2.6.2 The amended concentration of the carbon monoxi de (CO) for four-stroke engines shall be: 
Cco modification =Cco×15
Cco×Cco2% 
5.2.6.3 For the total measured concentration value (Cco  + Cco2) of any two-stroke engine which is 
not less than 10%, or the total measured concentration value (C co + Cco2) of any four-stroke 
engine which is not less than 15%, then the co ncentration value of the measured carbon monoxide 
(CO) shall not need to be modified in the above formulas 5.2.6.1 and 5.2.6.2. 
5.2.7 Number rounding off  One decimal place shall be kept for the roundi ng-off of the exhaust value for carbon monoxide 
(CO); the tens digit place shall be kept for th e rounding-off of the exha ust value for hydrocarbon 
(HC). 
5.2.8 Data recording - 9 - Enter the entire measurement data into Appendix A. 
 6 Single-gas fuel vehicl es and dual-fuel vehicles 
With regards to vehicles using single-gas fuel, de tection of emissions shall only be conducted with 
the relevant gas fuel; in respect of vehicles using dual-fuels, it is required to conduct emission 
detection with both fuels respectively. 
 7 Determination of the measurement results 
If there is any one inspection item value of the exhaust pollutants of  any vehicle which has 
exceeded the corresponding limit specified in Chapter 4, then the exhaust emissions of this vehicle 
shall be regarded as unqualified. 
 8 Implementation requirement 
8.1 From the implementation date of this Standard, the exhaust limits specified in Table 1 shall be 
applied to the type approval of motorcycles and mopeds and the exhaust monitoring of new 
vehicles; the manufacturers of th e motorcycles and mopeds shall treat the two-speed idle speed 
measurement results of the type approval tests as  the consistency guarantee of the enterprise 
production and the reference ba sis of its self-inspection. 
 From the implementation date of this Standa rd, the exhaust limits and measurement methods 
specified in Table 2 shall be applied to the e xhaust monitoring of any in-use motorcycles and 
mopeds. 
8.2 On the basis of the local actual situation, the local administrative depa rtments may select the 
two-speed idle speed method or the simple tran sient driving method as  the exhaust detection 
method for in-use vehicles in areas which are heavily polluted and have a large number of 
motorcycles and mopeds. With regard to any t ype of the same model in-use vehicles, when 
conducting routine environmental protection detect ion, only one type of the exhaust pollutant 
detection methods can be selected. 
8.3 Areas using a simple transient driving method shall be specified an em ission limit for each local 
exhaust pollutant, and the said limits shall be a pproved by the government departments at provincial 
levels, and be filed by the admi nistrative department for envir onmental protection of the State 
Council prior to implementation. 
 9 Implementation of this Standard 
The implementation date of this Standard shall be xx xx 200x (date). - 10 - Appendix A 
Recording Table for Pollutants  in Two-speed Idle Mode 
(Informative Annex) A.1 Vehicle information Vehicle model: __________ Manufacturer: ________________ Vehicle Identificati on Number (VIN): ___________ 
Engine Identificati on Number (EIN): ____________ 
Number of strokes per minute: ___________________ Idle speed (r/min): ____________________ Maximum net power rotation speed (r/min): ___________ High idle rotation speed________________ Fuel specification: ______________________ Lubricant specification: _________________ Fuel supply method: Carburet tor /electric injection ___________ 
Fuel injection system: ope n type/ closed type ____________ 
Pollution control unit: _________________ 
A.2 Test instruments 
Model number of the exha ust gas analyser: ______________ 
Model number of the tachometer: _______________ 
A.3 Test environment 
Atmospheric pressure: ____________ 
Temperature: _____________ Relative humidity: ________________ Test location: ________________________ Test date: _______________________ 
Test technician: ____________________ 
High idle speed Idle speed 
Contents 
Rotation 
speed r/min CO 
% CO 2 
% HC 
10-6 Rotation speed r/min CO 
%  
CO
2 
%  
HC 10
-6 
Measurement result         
Result /  / / /  / / - 11 - amendment 
Result 
rounding-off /    /    
 
 - 12 - Appendix B 
(Normative Annex) 
Measurement methods for simple transient driving mode 
B.1 Scope 
This Appendix specifies the test procedures for th e simple transient drivi ng mode conditions which 
are mentioned in 8.1 of this Standard. 
B.2 Test running cycle 
In accordance with the specifications set out in CA.2 of the GB14622-2007, an urban district 
running cycle must be conducted on the test motorcycle chassis dynamometer; and in accordance with the specifications  set out in C.2.1 of the GB18176-2007, a running cycle must be conducted to 
the test moped chassis dynamometer. 
B.3 Vehicles and fuels 
B.3.1 Test vehicles 
B.3.1.1 The mechanical condition of the test vehicl es must be sufficient, there must be no 
mechanical failures which may affect sa fety or lead to test deviations. 
B.3.1.2 There must be no leakage in the exhaust syst em, to avoid a decrease in the quantity of the 
exhaust gas collection. 
B.3.1.3 There must be no liquid leakage from the e ngine, gear-box and cooling system of the test 
vehicles. 
B.3.1.4 The tyre pressure shall be  within the normal range, the tyres shall be dry and clean. 
B.3.1.5 The driving wheels of the vehicles must be on the roller, the vehicl es must be laterally 
stable and well-spaced. 
B.3.1.6 Before conducting the test, the test vehicles sh all be pre-heated in accordance with the rules 
specified in the technical documents of the vehi cle manufacturer. The exhaust measurement must be 
started within 10 minutes  after the test vehicle has been pre-heated. 
B.3.2 Test fuels 
Commercially available fuels which conform to  the specifications set out in the technical 
documents of the vehicle manufacturers shall be used. 
B.4 Test equipment 
B.4.1 Chassis dynamometer 
A chassis dynamometer is mainly composed of a power-absorbing unit, a roller, an inertia 
simulation unit, a driving motor and a rotation speed  sensor. It is used to simulate the road 
resistance of vehicles. As a minimum, a chassis dynamometer mu st be able to simulate the 
acceleration and inertia of a vehicl e under normal road conditions. It must also simulate the mode 
conditions of a vehicle while the vehicle’s road  driving speed is steady or is accelerating – by 
controlling the power-absorbing unit. The mode of  speed deceleration is simulated by general 
flywheels, or by a chassis dynamometer which is able  to simulate the entire inertia of a vehicle 
driving on the road. - 13 - The chassis dynamometer must also be suitable for motorcycles or mopeds w ith a complete vehicle 
kerb mass not more than 400 kg. 
B.4.1.1 Power-absorbing unit B.4.1.1.1 Power-absorption of chassis dynamometer The total absorbed power of a chassis dynamomete r (Pa) includes the indi cated horsepower (IHP) 
and the parasitic power (PLHP) in  two parts. Unless otherwise spec ified, the power value displayed 
by the chassis dynamometer shall be the Pa value: 
Pa = IHP + PLHP 
IHP – Indicated horsepower, the absorbed  power of the power-absorb unit, kW; 
PLHP – Parasitic power, the power absorbed by the friction of the rotating parts, kW; B.4.1.1.2 See Section 4.12 of HJ/T 290-2006 for the t echnical requirements of  the coast-down test 
for parasitic power. 
B.4.1.1.3 See Section 4.13 of HJ/T 290- 2006 for the technical requiremen ts of the load  coast-down 
test for the chassis dynamometer. 
B.4.1.1.4 See Section 4.14 of HJ/T 290-2006 for the tec hnical requirements of the pressure sensor 
calibration for the chassis dynamometer. 
B.4.1.1.5 See Section 4.16.2 and Secti on 4.16.3 of HJ/T 290-2006 for th e technical requirements of 
the response time for the chassis dynamometer. 
B.4.1.1.6 The power absorbed by the power-absorb un it shall use 0.01kW as the adjustable unit. 
Within the environmental temperature range of 0
oC to 40oC, after the chassis dynamometer is pre-
heated, its power deviation shall not exceed ± 0.02kW or ± 2% of the power absorption, among 
these two, the larger value shall be selected. 
B.4.1.2 Roller technical requirements B.4.1.2.1 The chassis dynamometer shall be equipped w ith a single roll er, with a diameter of not 
less than 400 mm. 
B.4.1.2.2 The surface treatment of the roller must ensu re the tyre will not skid; the surface of the 
roller shall be dry; be able to ensure the measuring distance and speed accuracy; and the tyre 
abrasion and noise must be  kept to a minimum. 
B.4.1.3 Inertia B.4.1.3.1 Dynamometer inertia weight The chassis dynamometer shall be equipped with a machine flywheel; the to tal dynamometer inertia 
weight shall be 120 kg ± 15 kg. The deviation betw een the dynamometer inertia weight and 120 kg 
must be quantified, and a modification of coast- down test time shall be conducted in accordance 
with the actual dynamometer inertia weight. The accu racy of the actual dynamometer inertia weight 
shall be ± 2.5 kg, and shall be cl early stated on the plate of th e chassis dynamometer or the 
flywheel. 
B.4.1.3.2 Inertia simulation The chassis dynamometer must be able to simulate the inertia of any motorc ycle or moped with a 
complete vehicle kerb mass not exceeding 400 kg when using the acceleration of 1.47 m/s
2 as the 
accelerated speed. The simulation difference of the electrical inertia must not exceed 2%, and must 
be able to provide a 1 kg mass increment.  
B.4.1.4 Other requirements - 14 - B.4.1.4.1 The test vehicles on the chassis dynamometer must be horizontally positioned; and the 
chassis dynamometer must have a spacing gr ipping holder to hold the test vehicles. 
B.4.1.4.2 The chassis dynamometer must be suitable for vehicles with a maximum safe driving 
speed of 90 km/h or greater. 
B.4.1.4.3 In order to avoid the engi nes of the test vehicles beco ming over-heated during the test 
process, a cooling blower shall be  fitted. This cooling blower shall be located on the right front side 
of the test vehicle, at a distan ce of 30-40 cm away from the end of  the front wheels, the lower part 
of the cooling blower shall be 15-20 cm off the ground, the area of the air outlet shall be at least 
0.4m2, the ventilation quantity shall not be lower than 85m3/min and the wind speed shall not be 
lower than 4.5 m/s. 
B.4.1.4.4 The chassis dynamometer shal l be equipped with a system to  measure the rotation of the 
roller. The rotation measurement is used to calculate  the driving speed of a vehicle and the accuracy 
of the speed measurement must be ± 0.16 km/h. 
B.4.1.4.5 The chassis dynamometer will be able to measure the equivalent driving speed of a 
vehicle, with a distance accuracy of ± 2%. 
B.4.2 Exhaust gas sampling system and five gas analyser B.4.2.1 The main components of the five gas analys er and sampling system shall conform to the 
specifications set out in Section 5.1 of HJ/T 290-2006. 
B.4.2.2 The sampling system shall be designed so that  the materials which it is made of, and its 
materials which come into contact with the samp led gases are not contaminated or do not change 
the properties of the analysing gases, and also do not lead to any corrosion caused by any sampled 
gases. The sampling system must conform to the specifications set out in Section 5.2 of HJ/T 290-
2006. 
B.4.2.3 The sample tube shall conform to the spec ifications set out in Section 5.3 of HJ/T 290-2006. 
B.4.2.4 The length of the sample probe shall be insert ed into the gas exhaust extension tube at least 
400 mm, and shall conform to the specificati ons set out in Section 5.4 of HJ/T 290-2006. 
B.4.2.5 The five-gas analyser shall use the principles mentioned be low to check the concentration 
of the exhaust pollutants: use th e Non-Dispersive Infr ared (NDIR) method to  check the carbon 
monoxide (CO), hydrocarbon (H C) and carbon dioxide (CO
2); use the electrochemical method to 
check the nitric oxide (NO) and oxygen (O 2). Other principles shall be approved by the Ministry of 
Environmental Protection’s designated units before being used. The five-gas analyser shall conform 
to the specifications set out in Se ction 5.5 and Section 5.6 of HJ/T 290-2006. 
B.4.2.6 The analyser must be able to  maintain the test accuracy. When  considering the suitability of 
the calibrated gases and test gases, the following ca librated gases can be used, with an error margin 
of ± 1%. 
I, Zero gases: Concentration: O
2, 20.9%; N 2, balance. Impurity level: THC, CO, NO<1 x 10-6; CO 2 < 200 x 10-6. 
II, Low-range standard gases: 200 x 10
-6                             C 3H3 (Propane) 
0.50%                                    CO 6.0%                                      CO
2 
300 x 10-6                              NO - 15 - 99.99% pure balance gases   N 2 
III, High-range standard gases: 
3200 x 10-6                             C 3H3 (Propane) 
8.00%                                    CO 12.0%                                      CO
2 
3000 x 10-6                              NO 
99.99% pure balance gases   N 2 
B.4.3 Effusion meter B.4.3.1 The main components of an effusion meter must conform to the re gulations set out in 
Section 6.1 of HJ/T 290-2006. 
B.4.3.2 The specifications of the effusion meter and its  technical requirements  must conform to the 
regulations set out in Section 6.2 of HJ/T 290-2006. 
B.4.3.3 Technical requirements of the effusion meter components B.4.3.3.1 The diameter of the gas collecting tube must  be within the range of 60 – 75 mm, the gas 
pump shall ensure the output gases go through the ef fusion meter is within th e range of (30 - 70)L/s. 
B.4.3.3.2 Other technical requiremen ts of the effusion meter components must conform to the 
regulations set out in Section 6.3 of HJ/T 290-2006. 
B.4.3.4 The technical characteristic requirements of the effusion meter must conform to the 
regulations set out in Section 6.4.1 and Section 6.4.2 of the HJ/T 290-2006. 
B.4.4 Computer control system B.4.4.1 The test procedure, data collecting and analysis system is automatic. According to the 
parameter database of the vehicle, the software is able to automatically set up the vehicle load. 
B.4.4.2 The system is equipped with a clearly visi ble driver guide device (driver assistant). The 
guide device shall continuously display the requir ed speed, time (in seconds ) under test conditions, 
actual driving speed and time, e ngine rotation speed, brake applic ation and any other necessary 
reminders and warnings. The guide device shall also be able to display the state of the test and 
equipment and other required information. 
B.4.4.3 The system must be able to accurately reco rd and display the test procedure data, and be 
able to automatically carry out calculations and modifications. 
B.5 Test preparation 
B.5.1 Test environmental requirements 
Environmental temperature: 0
oC ~ 40oC; 
Relative humidity: < 85%. B.5.2 Before starting the test, record the information required by Appendix BA. 
B.5.3  Add a length of 600 mm with an inner diamet er of 40mm special seal ed connecting tube to 
the rear part of the exhaust muffler, the exhaust back pressure must not exceed 1.25 kPa, and will 
not affect the normal operation of the engine. The ma terials used to make th e exhaust tube extension 
must not affect the exhaust emissions, and are al so not affected by the chemical composition of the 
exhaust emissions. - 16 - B.5.4 Preparation and set up of the test equipment 
B.5.4.1 Pre-heat the analyser; it will reach a stable state after the pow er is connected for 30 minutes. 
If not adjusted within five minutes, the zero ga s and the measuring distan ce reading of HC, CO, 
NO, CO 2 shall be kept within the range  of the accuracy specification. 
B.5.4.2 Before the machine is switched off the samp ling system must be con tinuously cleaned for at 
least 15 minutes. At least 5 minutes  cleaning is required if the back -flush cleaning method has been 
used. 
B.5.4.3 The sample probe is inserted into the spec ial sealed connecting tu be for at least 400mm. 
B.5.4.4 Samples from independently-operated multi-exha ust tubes shall be taken at the same time. 
B.5.4.5 Within 2 minutes before each test, the analys er must complete its auto-zero purification, 
determination of ambient air and detection of HC residue. 
B.5.4.5.1 Use zero gases to purify HC, CO, CO 2, NO and O 2. 
B.5.4.5.2 After the ambient air has been  filtered by the sample probe, soft tube, filter and moisture 
separator, it is sent into the analyser through th e sampling pump. The concentr ation of all five test 
gases shall be directly recorde d, and not require any modification. 
B.5.4.5.3 The analyser shall determine the pollution le vel of the ambient air and the HC residue. 
When the collected sample gases: (1) in the ambient air, have reached, HC <7 x10-6, CO<0.02%, 
NO <25x10-6; (2) have a residue concentr ation of the HC in the sampling system higher than the 
sampling concentration of the ambient air but does not exceed 7 x10-6, then the instrument can be 
used. 
B.5.4.6 Chassis dynamometer pre-heat  When the chassis dynamometer is switched on, it must be pre-heated. When the chassis 
dynamometer is switched off or the required temper ature is not met, the chassis dynamometer shall 
automatically start to pre-heat and standby. 
B.5.4.7 Coast-down test After it is started and pre-heated, conduct a coas t-down test according to the programs set by the 
chassis dynamometer, after the coast-down test is qualified, the exhaust test under simple transient 
driving mode can be conducted. 
B.5.4.8 Load set of simple transient driving mode Before conducting the exhaust test, according to the ve hicle parameters, the syst em must be able to 
automatically set up the chassis dynamometer loa d. For motorcycles, it shall be conducted in 
accordance with the regulations specified in Section C.5.4 of GB14622-2007; for mopeds, it shall 
be conducted in accordance with the regulations  specified in Secti on C.5.2 of GB18176-2007.  
B.6 Test procedure 
B.6.1 Starting the engine 
B.6.1.1 Start the engine according to the inst ructions provided by the vehicle manufacturer. 
B.6.1.2 The engine maintains its idle speed for 40 seconds; when 40 seconds has passed, start 
operating circulation, meanwhile start taking samples. 
B.6.2 Idle speed B.6.2.1 Hand/foot operated transmission - 17 - B.6.2.1.1 During idle speed ope ration, the clutch must be engaged and the transmission must be in 
neutral. 
B.6.2.1.2 In order to allow acceleration to be performed as the test re quires, after the idle speed and 
5 seconds before acceleration, the cl utch of the motorcycle is dise ngaged and the transmission is put 
into first gear. 
B.6.2.1.3 The first idle speed period of each circul ation includes the 6 s econds of the clutch 
engagement and neutral position of the transmission, and the 5 seconds of the clutch disengagement 
and the first gear posi tion of the transmission. 
B.6.2.1.4 The middle idle speed period of each circul ation includes the 16 seconds of the clutch 
engagement and neutral position of the transmission, and the 5 seconds of the clutch disengagement 
and the first gear posi tion of the transmission. 
B.6.2.1.5 The last idle speed period of each circulat ion refers to the 7 seconds of the clutch 
engagement and neutral position of the transmission. 
B.6.2.2 Semi-automatic transmission To be carried out in accordance with the specifica tion of the manufacturer. If  it is not specified by 
the manufacturer, then it shall be  carried out as manual transmission. 
B.6.2.3 Automatic transmission The gear selector is not used during the test , unless specified by the manufacturer. If the 
manufacturer specifies use of the gear selector, th en the procedure shall be carried out using manual 
transmission. 
B.6.3 Acceleration B.6.3.1 During acceleration, the specified acceleration sh all be ensured, and the changing rate of the 
acceleration shall be kept as stable as possible. 
B.6.3.2 If the acceleration of the motorcycle does not use accelerat ed rotation for its specified 
range, then the accelerator must be fully depressed until the required vehicle speed is reached, then 
normal operations will be carried out as specified. 
B.6.4 Deceleration 
B.6.4.1 All speed decelerati on shall be carried out when the accelerator is completely disengaged 
and the clutch is engaged. When the vehicle speed  has decreased to 10 km/h, disengage the engine. 
B.6.4.2 In the case that the period of speed decele ration is longer than th e corresponding specified 
circulation rate, then the vehicle brake must be used in order to slow the vehicle to the specified 
circulation rate. 
B.6.4.3 In the case that the period of speed decelera tion is shorter than th e corresponding specified 
circulation rate, then there must be a period of st eady speed or idle speed to recover the specified 
circulation rate.  
B.6.4.4 When the speed deceleration is complete (the  motorcycle on the roller has stopped), engage 
the clutch and shift the transmission to neutral. 
B.6.5 Steady speed B.6.5.1 During the period of transition from acceleration to even speed, sudden increases or 
decreases in speed must be avoided. 
B.6.5.2 During even speed, the accelerator  position must be kept unchanged. - 18 - B.7 Limits to determine the exhaust pollutants 
B.7.1 The dilution ratio of the exhaust emissions  shall be calculated according to the formula 
below: 
 DR=[O2]amb−[O2]dil
[O2]amb−[O2]raw 
In which: DR – Dilution Ratio 
[O2]amb – the oxygen concentration (volume fraction)  in the surrounding ambient air, percentage 
[O2]dil – the reading of the oxygen concentration ( volume fraction) of the oxygen sensor in the 
effusion meter, percentage. 
[O2]raw – the reading of the oxygen  concentration (volume fraction)  of the oxygen sensor in the 
five-gas analyser, percentage. 
B.7.2 The actual flow rate of the exhaust emissi ons shall be calculated according to the formula 
below: 
 Qe=Qact×P
T×273.2
101.3×DR 
In which: Q e – the actual flow rate of  the exhaust emissions, L/s; 
Qact -the actual flow rate of the volumetric dilution; 
P – the reading of the pressure sensor of the diluted exhaust emissions, kPa; 
T – the reading of the temperature sensor  of the diluted exhaust emissions, K. 
B.7.3 Measurement result of the exhaust emissions B.7.3.1 The measurement result of the emitted CO 
 
COM=∑mco
S 
In which: CO M – the amount of CO emitted per kilometre during the test, g/km; 
S – the driving distance of the vehicle during test, km; 
∑mCO  the total amount of CO emitted per second during the test, g; 
In the formula, the ∑mCO shall be calculated according to the formula below: 
 mco=10−2×[CO]×Dco×Qe 
In which: m co – the actual amount of CO emitted, g/s; 
[CO] – the actual emitted CO concentration (volume fraction), %; D
co – the CO density under standard conditions, g/L. 
 B.7.3.2 The measurement result of the emitted HC 
 HCM=∑mHC
S 
In which: HC M – the amount of HC emitted per kilometre during the test, g/km; 
S – the driving dist ance of the vehicle during the test, km; 
∑mHC – the total amount of HC emitted per second during the test, g; - 19 - In the formula, the ∑mHC shall be calculated according to the formula below: 
 mHC=10−6×[HC]×DHC×Qe 
In which:  m HC– the actual amount of HC emitted, g/s; 
[HC] – the actual concentration of HC emitted (volume fraction), 10-6; D
HC – the HC density under standard conditions, g/L. 
B.7.3.3 The measurement result of the emitted NOx The nitrogen oxide (NOx) is presented by the equivalent of NO
2. The measured value of NO shall 
be automatically calculated and rounde d-off by the system main processor. 
 NOxM=46
30×∑mNO
S 
In which: NOx M – the amount of NOx emitted per kilometre during the test, g/km; 
S – the driving dist ance of the vehicle during the test, km; 
∑mNO – the total amount of NO emitted per second during the test, g; 
In the formula, the ∑mNO shall be calculated accord ing to the formula below: 
 mNO=10−6×[NO]×DNO×Qe 
In which: m NO – the actual amount of NO emitted, g/s; 
[NO] – the actual concentration of NO emitted (volume fraction), 10-6; 
DNO – the NO density under standard conditions, g/L. 
B.7.4 The test procedures and results data shall be recorded and kept in the system database. 
 - 20 - Appendix BA 
Report format of the test result Test Result of the Exhaust Pollutants under Simple Transient Driving Mode Conditions 
 Name of test station: ________________ Test date: _____________________________ Test operator: _________________________ Test driver: _________________________  BA.1 Vehicle information Vehicle model: ____________________ Vehicle manufacturer: _______________________ Reference mass: ______________________ Tyre pressure: _________________ Transmission model: _________________ Gear number: __________________________ Engine model: _______________________ Engine manufacturer: __________________________ Cylinder numbers: __________________________ Engine displacement: ______________________________ Fuel supply method: _______________________________ Catalytic converter model: ______________________ Total mileage: ______________________________ Fuel specification: ________________________ Number of number plate: _______________________ Vehicle identifica tion number: _____________ 
Vehicle registration date: _______________________ 
Name and contact information of vehicle owner: __________________  BA.2 Test equipment Equipment authentication code: Equipment name: __________________________ Model number: _____________________________ Manufacturer: _______________________________ Chassis dynamometer: _________________________ - 21 - Exhaust emission analyser: _______________ 
 BA.3 Test environment state: Temperature: ______________________________ Atmospheric pressure: ________________________ Relative humidity: __________________________________  BA.4 Test result and determination: 
Exhaust pollutants HC CO NOx 
Test results (g/km)    
Limits (g/km)    
Determination result Qualified/unqualified Qualified/unqualified Qualified/unqualified 
Determination Passed/Failed