Document ID: chunk:federal_register_of_legislation:F2023L01530:body:0:p47
Version: federal_register_of_legislation:F2023L01530
Segment Type: other
Provision Reference: 
Character Range: 131609–134474

a space that is large enough or ventilated to prevent the build-up of hydrogen to more than 10 per cent of the targeted criteria in the passenger and luggage compartments.
         Post-crash data collection in enclosed spaces commences when the vehicle comes to a rest. Data from the sensors are collected at least every 5 seconds and continue for a period of 60 minutes after the test. A first-order lag (time constant) up to a maximum of 5 seconds may be applied to the measurements to provide "smoothing" and filter the effects of spurious data points.
         The filtered readings from each sensor shall be below the targeted criteria of 4.0 per cent for hydrogen or 3.0 per cent for helium at all times throughout the 60 minutes post-crash test period.
         3. Compliance test for single failure conditions
         Either test procedure of Annex 5, paragraph 3.1. or paragraph 3.2. shall be executed:
         3.1.  Test procedure for vehicle equipped with hydrogen gas leakage detectors
         3.1.1. Test condition
         3.1.1.1 Test vehicle: The propulsion system of the test vehicle is started, warmed up to its normal operating temperature, and left operating for the test duration. If the vehicle is not a fuel cell vehicle, it is warmed up and kept idling. If the test vehicle has a system to stop idling automatically, measures are taken so as to prevent the engine from stopping.
         3.1.1.2. Test gas: Two mixtures of air and hydrogen gas: 3.0 per cent concentration (or less) of hydrogen in the air to verify function of the warning, and 4.0 per cent concentration (or less) of hydrogen in the air to verify the shut-down function. The proper concentrations are selected based on the recommendation (or the detector specification) by the manufacturer.
         3.1.2. Test method
         3.1.2.1. Preparation for the test: The test is conducted without any influence of wind by appropriate means such as:
              (a) A test gas induction hose is attached to the hydrogen gas leakage detector;
              (b) The hydrogen leak detector is enclosed with a cover to make gas stay around hydrogen leak detector.
         3.1.2.2. Execution of the test
              (a) Test gas is blown to the hydrogen gas leakage detector;
              (b) Proper function of the warning system is confirmed when tested with the gas to verify function of the warning;
              (c) The main shut-off valve is confirmed to be closed when tested with the gas to verify function of the shut-down. For example, the monitoring of the electric power to the shut-off valve or of the sound of the shut-off valve activation may be used to confirm the operation of the main shut-off valve of the hydrogen supply.
         3.2. Test procedure for integrity of enclosed spaces and detection systems.
         3.2.1. Preparation:
         3.2.1.1.