5.9.1.2 The settings of inlet restriction and exhaust back pressure shall be adjusted to the upper limits as specified by the manufacturer in accordance with 5.2.4 and 5.2.5, respectively.
5.9.1 Main exhaust components CO, CO2, HC, NOx9, O2
5.9.2.1 An analytical system for the determination of the gaseous emissions is the raw exhaust gas shall be based on the use of the following analysers:
.1 HFID analyser for the measurement of hydrocarbons;
.2 NDIR analyser for the measurement of carbon monoxide and carbon dioxide;
.3 HCLD or equipment analyser for the measurement nitrogen oxides; and
.4 PMD, ECS or ZRDO for the measurement of oxygen.
5.9.2.2 For the raw exhaust gas, the sample for all components may be taken with one sampling probe or with two sampling probes located in close proximity and internally split to the different analysers. Care must be taken that no condensation of the exhaust components (including water and sulphuric acid) occurs at any point of the analytic system.
5.9.2.3 Specifications and calibration of these analysers shall be as set oils in appendices 5 and 6 of this Code, respectively.
5.9.3 Sampling for gaseous emissions
5.9.3.1 The sampling probes for the gaseous emissions shall be fitted at least 0.5m or 3 times the diameter of the exhaust pipe - whichever is the larger - upstream of the exit of the exhaust gas system, as far as practicable, but sufficiently close sit the engine so as so ensure an exhaust gas temperature of at least 343 K (70｡?) at the probe.
5.9.3.2 In the case of a multi-cylinder engine with a branched exhaust manifold, the inlet of the probe shall be treated sufficiently far downstream so as to ensure that the sample is representative of the average exhaust emission from all cylinders. In multi-cylinder engines having distinct groups of manifolds, such as is a "Vee" engine configuration, it is permissible to acquire a sample from each group individually and calculate an average exhaust emission. Other methods which have been shown to correlate with the above methods may be used. For exhaust emission calculation, the total exhaust mass flow must be used.
5.9.3.3 If the composition of the exhaust gas is influenced by any exhaust after treatment system, the exhaust sample must be taken downstream of this device.
5.9.4 Checking of the analysers
The emission analysers shall be set at zero and spanned.
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5.9.5 Teat cycles
All engines shall be tested in accordance with the teat cycles as defined in 3.2. This takes into account the variations in engine application.
5.9.6 Test sequence
5.9.6.1 After the procedures in 5.9.1 to 5.9.5 have been completed, the test sequence shall be started. The engine shall he operated in each mode in accordance with the appropriate seas cycles defined in 3.2.
5.9.6.2 During each mode of the test cycle after the initial transition period, the specified speed shall be held so within ± 1% of rated speed or ±3 min -1, whichever is greater, except for low idle which shall be within the tolerances declared by the manufacturer. The specific torque shall be held so that the average, over the period during which the measurements are to be taken, is within ± 2% of the maximum torque as the test speed.
5.9.7 Analyser response
The output of the analysers shall be recorded, birth during the test and during all response checks (zero and span), on a strip chart recorder or measured with an equivalent data acquisition system with the exhaust gas flowing through the analysers as least during the last ten minutes of each mode.
5.9.8 Engine conditions
The engine speed and load, intake air temperature and fuel flow shall be measured as each mode once the engine has been stabilised. The exhaust gas flow shall be measured or calculated and recorded.
5.9.9 Re-checking the analysers
After the emission test, the calibration of the analysers shall be re-checked using a zero gas and the same span gas as used prior to the measurements. The test shall be considered acceptable if the difference between the two calibration results is less than 2%.
5.10 TEST REPORT
5.10.1 For every engine tested for pre-certification or for initial certification on board without pre-certification, the engine manufacturer shall prepare a test report which shall contain, as a minimum, the data asset out in appendix 4 of this Code. The original of the test report shall be maintained on file with the engine manufacturer' and a certified true copy shall be maintained on file by the Administration.
5.10.2 The test report, either an original or certified true copy, shall be attached as a permanent part of an engine's Technical File.
5.11 DATA EVALUATION FOR GASEOUS EMISSIONS
For the evaluation of the gaseous emissions, the chart reading of the last 60 seconds of each mode shall be averaged, and the average concentrations (cone) of CO, CO2, NOx, and O2 during each mode shall be determined from the average chart readings and the corresponding calibration data.
