Council Directive of 20 March 1970 on the approximation of the laws of the Member States on measures to be taken against air pollution by emissions from motor vehicles (70/220/EEC) (repealed)

[F1 [F2 4. TEST EQUIPMENT FOR EVAPORATIVE TEST U.K.

4.1. Chassis dynamometer U.K.

The chassis dynamometer must meet the requirements of Annex III.

4.2. Evaporative emission measurement enclosure U.K.

The evaporative emission measurement enclosure must be a gas-tight rectangular measuring chamber able to contain the vehicle under test. The vehicle must be accessible from all sides and the enclosure when sealed must be gas tight in accordance with Appendix 1. The inner surface of the enclosure must be impermeable and non-reactive to hydrocarbons. The temperature conditioning system must be capable of controlling the internal enclosure air temperature to follow the prescribed temperature versus time profile throughout the test, and an average tolerance of ± 1 K over the duration of the test.

The control system must be tuned to provide a smooth temperature pattern that has a minimum of overshoot, hunting, and instability about the desired long-term ambient temperature profile. Interior surface temperatures must not be less than 278 °K (5 °C) nor more than 320 °K (55 °C) at any time during the diurnal emission test.

Wall design must be such as to promote good dissipation of heat. Interior surface temperatures must not be below 293 °K (20 °C), nor above 325 °K (52 °C) for the duration of the hot soak test.

To accommodate the volume changes due to enclosure temperature changes, either a variable-volume or fixed-volume enclosure may be used.

4.2.1. Variable-volume enclosure U.K.

The variable-volume enclosure expands and contracts in response to the temperature change of the air mass in the enclosure. Two potential means of accommodating the internal volume changes are movable panel(s), or a bellows design, in which an impermeable bag or bags inside the enclosure expand(s) and contracts(s) in response to internal pressure changes by exchanging air from outside the enclosure. Any design for volume accommodation must maintain the integrity of the enclosure as specified in Appendix 1 over the specified temperature range.

Any method of volume accommodation must limit the differential between the enclosure internal pressure and the barometric pressure to a maximum value of ± 5 hPa.

The enclosure must be capable of latching to a fixed volume. A variable volume enclosure must be capable of accommodating a ± 7 % change from its ‘ nominal volume ’ (see Appendix 1 section 2.1.1), taking into account temperature and barometric pressure variation during testing.

4.2.2. Fixed-volume enclosure U.K.

The fixed-volume enclosure must be constructed with rigid panels that maintain a fixed enclosure volume, and meet the requirements below.

4.2.2.1. The enclosure must be equipped with an outlet flow stream that withdrawns air at a low, constant rate from the enclosure throughout the test. An inlet flow stream may provide make-up air to balance the outgoing flow with incoming ambient air. Inlet air must be filtered with activated carbon to provide a relatively constant hydrocarbon level. Any method of volume accommodation must maintain the differential between the enclosure internal pressure and the barometric pressure between 0 and -5 hPa. U.K.

4.2.2.2. The equipment must be capable of measuring the mass of hydrocarbon in the inlet and outlet flow streams with a resolution of 0,01 gram. A bag sampling system may be used to collect a proportional sample of the air withdrawn from and admitted to the enclosure. Alternatively, the inlet and outlet flow streams may be continuously analysed using an on-line FID analyser and integrated with the flow measurements to provide a continuous record of the mass hydrocarbon removal. U.K.

4.3. Analytical systems U.K.

4.3.1. Hydrocarbon analyser U.K.

4.3.1.1. The atmosphere within the chamber is monitored using a hydrocarbon detector of the flame ionization detector (FID) type. Sample gas must be drawn from the mid-point of one side wall or roof of the chamber and any bypass flow must be returned to the enclosure, preferably to a point immediately downstream of the mixing fan. U.K.

4.3.1.2. The hydrocarbon analyser must have a response time to 90 % of final reading of less than 1,5 seconds. Its stability must be better than 2 % of full scale at zero and at 80 % ± 20 % of full scale over a 15-minute period for all operational ranges. U.K.

4.3.1.3. The repeatability of the analyser expressed as one standard deviation must be better than 1 % of full scale deflection at zero and at 80 % ± 20 % of full scale on all ranges used. U.K.

4.3.1.4. The operational ranges of the analyser must be chosen to give best resolution over the measurement, calibration and leak checking procedures. U.K.

4.3.2. Hydrocarbon analyser data recording system U.K.

4.3.2.1. The hydrocarbon analyser must be fitted with a device to record electrical signal output either by strip chart recorder or other data processing system at a frequency of at least once per minute. The recording system must have operating characteristics at least equivalent to the signal being recorded and must provide a permanent record of results. The record must show a positive indication of the beginning and end of the hot soak or diurnal emission test (including beginning and end of sampling periods along with the time elapsed between start and completion of each test). U.K.

Note: U.K.

1. Evaporative emission control families — details clarified. U.K.

2. Tailpipe emissions may be measured during type I test drive, but these are not used for legislative purposes. Exhaust emission legislative test remains separate. U.K.

4.4. Fuel tank heating (only applicable for gasoline canister load option) U.K.

4.4.1. The fuel in the vehicle tank(s) must be heated by a controllable source of heat; for example a heating pad of 2 000  W capacity is suitable. The heating system must apply heat evenly to the tank walls beneath the level of the fuel so as not to cause local overheating of the fuel. Heat must not be applied to the vapour in the tank above the fuel. U.K.

4.4.2. The tank heating device must make it possible to heat the fuel in the tank evenly by 14 °K from 289 °K (16 °C) within 60 minutes, with the temperature sensor position as in 5.1.1. The heating system must be capable of controlling the fuel temperature to ± 1,5 °K of the required temperature during the tank heating process. U.K.

4.5. Temperature recording U.K.

4.5.1. The temperature in the chamber is recorded at two points by temperature sensors which are connected so as to show a mean value. The measuring points are extended approximately 0,1 m into the enclosure from the vertical centre line of each side wall at a height of 0,9 ± 0,2 m. U.K.

4.5.2. The temperatures of the fuel tank(s) are recorded by means of the sensor positioned in the fuel tank as in 5.1.1 in the case of use of the gasoline canister load option (5.1.5). U.K.

4.5.3. Temperatures must, throughout the evaporative emission measurements, be recorded or entered into a data processing system at a frequency of at least once per minute. U.K.

4.5.4. The accuracy of the temperature recording system must be within ± 1,0 °K and the temperature must be capable of being resolved to ± 04, °K. U.K.

4.5.5. The recording or data processing system must be capable of resolving time to ± 15 seconds. U.K.

4.6. Pressure recording U.K.

4.6.1. The difference Δ _p between barometric pressure within the test area and the enclosure internal pressure must, throughout the evaporative emission measurements, be recorded or entered into a data processing system at a frequency of at least once per minute. U.K.

4.6.2. The accuracy of the pressure recording system must be within ± 2 hPa and the pressure must be capable of being resolved to ± 0,2 hPa. U.K.

4.6.3. The recording or data processing system must be capable of resolving time to ± 15 seconds. U.K.

4.7. Fans U.K.

4.7.1. By the use of one or more fans or blowers with the SHED door(s) open it must be possible to reduce the hydrocarbon concentration in the chamber to the ambient hydrocarbon level. U.K.

4.7.2. The chamber must have one or more fans or blowers of likely capacity 0,1 to 0,5 m ³ s ^-1 with which to thoroughly mix the atmosphere in the enclosure. It must be possible to attain an even temperature and hydrocarbon concentration in the chamber during measurements. The vehicle in the enclosure must not be subjected to a direct stream of air from the fans or blowers. U.K.

4.8. Gases U.K.

4.8.1. The following pure gases must be available for calibration and operation: U.K.

• purified synthetic air (purity: < 1 ppm C ₁ equivalent ≤ 1 ppm CO, ≤ 400 ppm CO ₂ , ≤ 0,1 ppm NO); oxygen content between 18 % and 21 % by volume,

• hydrocarbon analyser fuel gas (40 % ± 2 % hydrogen, and balance helium with less than 1 ppm C ₁ equivalent hydrocarbon, less than 400 ppm CO ₂ ),

  • propane (C ₃ H ₈ ), 99,5 % minimum purity,

  • butane (C ₄ H ₁₀ ), 98 % minimum purity,

  • nitrogen (N ₂ ), 98 % minimum purity.

4.8.2. Calibration and span gases must be available containing mixtures of propane (C ₃ H ₈ ) and purified synthetic air. The true concentrations of a calibration gas must be within ± 2 % of stated figures. The accuracy of the diluted gases obtained when using a gas divider must be to within ± 2 % of the true value. The concentrations specified in Appendix 1 may also be obtained by the use of a gas divider using synthetic air as the diluent gas. U.K.

4.9. Additional equipment U.K.

4.9.1. The absolute humidity in the tests area must be measurable to within ± 5 %.] ] U.K.

Textual Amendments

F1 Substituted by Council Directive of 26 June 1991 amending Directive 70/220/EEC on the approximation of the laws of the Member States relating to measures to be taken against air pollution by emissions from motor vehicles (91/441/EEC).

F2 Substituted by Directive 98/69/EC of the European Parliament and of the Council of 13 October 1998 relating to measures to be taken against air pollution by emissions from motor vehicles and amending Council Directive 70/220/EEC.