Directive 2005/55/EC of the European Parliament and of the Council (repealed)Show full title

2. DYNAMOMETER AND TEST CELL EQUIPMENT

The following equipment shall be used for emission tests of engines on engine dynamometers.

2.1. Engine dynamometer

An engine dynamometer shall be used with adequate characteristics to perform the test cycles described in Appendices 1 and 2 to this Annex. The speed measuring system shall have an accuracy of ± 2 % of reading. The torque measuring system shall have an accuracy of ± 3 % of reading in the range > 20 % of full scale, and an accuracy of ± 0,6 % of full scale in the range ≤ 20 % of full scale.

2.2. Other instruments

Measuring instruments for fuel consumption, air consumption, temperature of coolant and lubricant, exhaust gas pressure and intake manifold depression, exhaust gas temperature, air intake temperature, atmospheric pressure, humidity and fuel temperature shall be used, as required. These instruments shall satisfy the requirements given in Table 8:

Table 8
Accuracy of measuring instruments
Measuring instrument	Accuracy
Fuel consumption	± 2 % of engine's maximum value
Air consumption	± 2 % of engine's maximum value
Temperatures ≤ 600 K (327 °C)	± 2 K absolute
Temperatures >600 K (327 °C)	± 1 % of reading
Atmospheric pressure	± 0,1 kPa absolute
Exhaust gas pressure	± 0,2 kPa absolute
Intake depression	± 0,05 kPa absolute
Other pressures	± 0,1 kPa absolute
Relative humidity	± 3 % absolute
Absolute humidity	± 5 % of reading

2.3. Exhaust gas flow

For calculation of the emissions in the raw exhaust, it is necessary to know the exhaust gas flow (see Section 4.4 of Appendix 1). For the determination of the exhaust flow either of the following methods may be used:

a)

direct measurement of the exhaust flow by flow nozzle or equivalent metering system;

b)

measurement of the air flow and the fuel flow by suitable metering systems and calculation of the exhaust flow by the following equation:

G_EXHW = G_AIRW + G_FUEL (for wet exhaust mass)

The accuracy of exhaust flow determination shall be ± 2,5 % of reading or better.

2.4. Diluted exhaust gas flow

For calculation of the emissions in the diluted exhaust using a full flow dilution system (mandatory for the ETC), it is necessary to know the diluted exhaust gas flow (see Section 4.3 of Appendix 2). The total mass flow rate of the diluted exhaust (G_TOTW) or the total mass of the diluted exhaust gas over the cycle (M_TOTW) shall be measured with a PDP or CFV (Annex V, Section 2.3.1). The accuracy shall be ± 2 % of reading or better, and shall be determined according to the provisions of Annex III, Appendix 5, Section 2.4.