L 290/572
EN
Official Journal of the European Union
4.5.3.
The recording or data processing system shall be capable of resolving time to ± 15 seconds.
4.6.
Fans
10.11.2022
The fans shall meet the requirements of paragraphs 4.6.1. and 4.6.2. of this annex.
4.6.1.
By the use of one or more fans or blowers with the Sealed Housing Evaporative Determination (SHED) door(s) open, it shall be possible to reduce the hydrocarbons concentration in the chamber to the ambient hydrocarbon level.
4.6.2.
The chamber shall have one or more fans or blowers of like capacity 0.1 to 0.5 m3/sec. with which to thoroughly mix the atmosphere in the enclosure.
It shall be possible to attain an even temperature and hydrocarbon concentration in the chamber during measurements.
The vehicle in the enclosure shall not be subjected to a direct stream of air from the fans or blowers.
4.7.
Calibration gases The gases shall meet the requirements of paragraphs 4.7.1. and 4.7.2. of this annex.
4.7.1.
The following pure gases shall be available for calibration and operation: Purified synthetic air: (purity < 1 ppm C1 equivalent, ≤ 1 ppm CO, ≤ 400 ppm CO2, ≤ 0.1 ppm NO); Oxygen content between 18 and 21 per cent by volume.
Hydrocarbon analyser fuel gas: (40 ± 2 per cent hydrogen, and balance helium with less than 1 ppm C1 equivalent hydrocarbon, less than 400 ppm CO2), Propane (C3H8):
99.5 per cent minimum purity.
Butane (C4H10):
98 per cent minimum purity.
Nitrogen (N2):
98 per cent minimum purity.
4.7.2.
Calibration and span gases shall be available containing mixtures of propane (C3H8) and purified synthetic air.
The true concentrations of a calibration gas shall be within 2 per cent of the stated figures.
The accuracy of the diluted gases obtained when using a gas divider shall be to within ± 2 per cent of the true value.
The concentrations specified in paragraphs 4.2.3. and 4.3.3. of this annex may also be obtained by the use of a gas divider using synthetic air as the dilutant gas.
4.8.
Carbon canister weighing scale for depressurisation puff loss overflow measurement The carbon canister weighing scale shall have an accuracy of ± 0.02 g.
4.9.
Fuel tank heating (only applicable for gasoline canister load option)
4.9.1.
The fuel in the vehicle tank(s) shall be heated by a controllable source of heat; for example a heating pad of 2 000 W capacity is suitable.
The heating system shall apply heat evenly to the tank walls beneath the level of the fuel so as not to cause local overheating of the fuel.
Heat shall not be applied to the vapour in the tank above the fuel.
4.9.2.
The tank heating device shall make it possible to heat the fuel in the tank evenly by 14 °C from 16 °C within 60 minutes, with the temperature sensor position as in paragraph 4.9.3. of this annex.
The heating system shall be capable of controlling the fuel temperature to ± 1.5 °C of the required temperature during the tank heating process.
4.9.3.
The fuel tank of the vehicle shall, without introducing any leaks, be equipped with a temperature sensor to enable the temperature to be measured at the mid-point of the fuel in the fuel tank when filled to 40 per cent of its capacity.
5.
Procedure for carbon canister bench ageing and PF determination
5.1.
Carbon canister bench ageing Before performing the hot soak and diurnal losses sequences, the carbon canister shall be aged according to the procedure described in Figure C3/1.