Document ID: chunk:federal_register_of_legislation:F2024L00446:reg:9:p34
Version: federal_register_of_legislation:F2024L00446
Segment Type: reg
Provision Reference: reg 9 (pt 34/37)
Character Range: 1872600–1875564

this annex.
               One of the methods specified in paragraphs 6.5.5.3. and 6.5.5.4. of this annex shall be used to precondition the evaporative canister. For vehicles with multiple canisters, each canister shall be preconditioned separately.
              6.5.5.2.1. Canister emissions are measured to determine breakthrough.
              Breakthrough is here defined as the point at which the cumulative quantity of hydrocarbons emitted is equal to 2 grams.
              6.5.5.2.2. Breakthrough may be verified using the evaporative emission enclosure as described in paragraphs 6.5.5.3. and 6.5.5.4. of this annex. Alternatively, breakthrough may be determined using an auxiliary evaporative canister connected downstream of the vehicle's canister. The auxiliary canister shall be well purged with dry air prior to loading.
              6.5.5.2.3. The measuring chamber shall be purged for several minutes immediately before the test until a stable background is obtained. The chamber air mixing fan(s) shall be switched on at this time.
              The hydrocarbon analyser shall be zeroed and spanned immediately before the test.
              6.5.5.3. Canister loading with repeated heat builds to breakthrough
              6.5.5.3.1. The fuel tank(s) of the vehicle(s) is (are) emptied using the fuel tank drain(s). This shall be done so as not to abnormally purge or abnormally load the evaporative control devices fitted to the vehicle. Removal of the fuel cap is normally sufficient to achieve this.
              6.5.5.3.2. The fuel tank(s) is (are) refilled with test fuel at a temperature of between 10 to 14 °C to 40  2 per cent of the tank's normal volumetric capacity. The fuel cap(s) of the vehicle shall be fitted at this point.
              6.5.5.3.3. Within one hour of being refuelled the vehicle shall be placed, with the engine shut off, in the evaporative emission enclosure. The fuel tank temperature sensor is connected to the temperature recording system. A heat source shall be properly positioned with respect to the fuel tank(s) and connected to the temperature controller. The heat source is specified in paragraph 4.9. of this annex. In the case of vehicles fitted with more than one fuel tank, all the tanks shall be heated in the same way as described below. The temperatures of the tanks shall be identical to within 1.5 °C.
              6.5.5.3.4. The fuel may be artificially heated to the starting diurnal temperature of 20 °C  1 °C.
              6.5.5.3.5. When the fuel temperature reaches at least 19 °C, the following steps shall be taken immediately: the purge blower shall be turned off; enclosure doors closed and sealed; and measurement initiated of the hydrocarbon level in the enclosure.
              6.5.5.3.6. When the fuel temperature of the fuel tank reaches 20 °C a linear heat build of 15 °C begins. The fuel shall be heated in such a way that the temperature of the fuel during the heating