Vehicle Emissions



Vehicle Exhaust Emissions Test

If a passenger vehicles emission levels are to be determined precisely, then the vehicle must be tested in an emissions test cell under standardized conditions which provide an accurate reflection of the actual driving conditions.  This is the only means of ensuring that individual emissions tests remain mutually comparable.  

The vehicle to be tested is parked with its drive wheels on special rollers the rotating resistance of which can be adjusted to simulate friction losses and aerodynamic resistance.  Inertial masses can be switched in or out to simulate the vehicles weight.  The required cooling is provided by a fan mounted 30cm from the vehicle which tracks the vehicle speed to within +/- 5km/h.  The measurement of emissions levels is based on a simulated driving pattern which progresses through a precisely defined driving cycle incorporating various vehicle speeds.  

The exhaust gases produced during this driving cycle are collected for subsequent analysis of pollutant mass.  The analysis procedures (NDIR analysers for CO & CO2, flame-ionization analysers for HC, NMHC and chemiluminescent analysers for NOx) have in the meantime been made uniform.  The manner in which exhaust gases are collected and the procedures for determining emissions have largely been standardized in the various countries, but the driving cycles have not.  In some countries, regulations on exhaust emissions are supplemented by limits on evaporative-emissions losses from the fuel system.

Key Benefits

We can test any unleaded passenger vehicle that is required for licensing in Hong Kong within the range of 652kg to 3000Kg in vehicle weight.  Both our Dynamometer and Emissions systems are fully computer controlled and very simple to use, giving us detailed and accurate test results.  We can provide a fast turnaround in that it takes 40 minutes to actually test the car (the vehicle has to be soaked for a minimum of 6 hours previous to testing) but we generally return the vehicle and test report to customers the next day after delivery.  

Working Hours: Monday to Saturday 9:00am to 6:00pm


Our Facility is capable of performing the Drive Cycle test up to European Regulation (EC) 715/2007 and Commission Regulation (EC) 692/2008 amended up to 566/2011 (with OBD) (5b). This test cycle uses a hypothetical driving curve which is calculated to provide a reasonable approximation of driver behaviour in urban traffic. This new ECE/EC test cycle is presently binding in the following countries: Belgium, Denmark, France, Germany, Great Britain, Greece, Ireland, Luxemburg, Netherlands, Portugal & Spain. It is also adopted by the Hong Kong Environmental Protection Department as an acceptable method for approval of vehicles registered in Hong Kong. 

European Regulation (EC) 715/2007 and Commission Regulation (EC) 692/2008 amended up to 566/2011 (with OBD) (5b) Emission Limits

All Passenger Vehicles (GVW<2500Kg)

CO = 1000   mg/km 

HC = 100     mg/km 

NOx = 60     mg/km

NMHC = 68 mg/km

PM = 4.5     mg/km (Apply for GDI only)




Home Up

Send mail to with questions or comments about this web site.
Copyright 2016  Hong Kong Exhaust Emission Laboratory Limited

Last modified: 2016-08-29