Document ID: chunk:federal_register_of_legislation:F2021C01210:reg:200:p7
Version: federal_register_of_legislation:F2021C01210
Segment Type: reg
Provision Reference: reg 200 (pt 7/8)
Character Range: 100520–103450

by-pass valve may be provided upstream of the opacimeter to isolate it from the exhaust-gas flow when no measurement is being made.
        3.3  A cooling system may also be required upstream of the opacimeter.
Annex 10
"ECE" METHOD OF MEASURING THE NET POWER OF C.I. ENGINES

  1.  PURPOSE
        These provisions apply to the method for representing the curve of the power at full load of an internal combustion engine as a function of engine speed.

  2.  SCOPE
        This method applies to internal combustion engines used for the propulsion of the vehicles covered by this Regulation and Regulation No. 15 (E/ECE/324-E/ECE/505/Rev.l/Add.14/Rev.3).
The engines belong to one of the following categories:
          Reciprocating piston engines (positive ignition or compression ignition) excluding free piston engines;
Rotary piston engines.
These engines may be naturally aspirated or supercharged.

  3.  DEFINITIONS
        For the purposes of these provisions,
        "Net power" means the power obtained on a test bench at the end of the crankshaft or its equivalent 1/ at the corresponding engine speed with the auxiliaries listed in table 1;
        "Standard production equipment"  means any equipment provided by the manufacturer for a particular engine application.

  4.  ACCURACY OF MEASUREMENTS
        4.1  Torque
+ 1 per cent of measured torque. 2/
        4.2  Engine speed
+ 0.5 per cent of measured speed.

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        l/ If power measurement can be carried out only on an engine with the gear-box mounted, the efficiency of the gear-box shall be taken into account.
        2/ The torque measuring system shall be calibrated to take friction losses into account. The accuracy in the lower half of the measuring range of the dynamometer bench may be + 2 per cent of measured torque.
4.3  Fuel consumption
+ 1 per cent of measured consumption.
        4.4  Fuel temperature
+ 2 K 4.5
        4.5  Air temperature
+ 2 K
        4.6  Barometric pressure
+ 100 Pa
        4.7  Pressure in intake duct (see note 1a to table 1)
+ 50 Pa
        4.8  Pressure in exhaust duct (see note lb to table 1)
+ 200 Pa

  5.  TEST FOR MEASURING NET ENGINE POWER
        5.1  Auxiliaries
        5.1.1 Auxiliaries to be fitted
        During the test, the auxiliaries necessary for the engine operation in the intended application (as listed in table 1) shall be installed on the test bench as far as possible in the same position as in the intended application.
        5.1.2 Auxiliaries to be removed
        Certain vehicle accessories necessary only for the operation of the vehicle and which may be mounted on the engine shall be removed for the test. The following non-exhaustive list is given as a sample.
Air compressor for brakes;
Power steering compressor;
Suspension compressor;
Air-conditioning system.
        Where accessories cannot be removed, the power they absorb in the unloaded condition may be