Document ID: chunk:federal_register_of_legislation:F2015L02109:body:0:p32
Version: federal_register_of_legislation:F2015L02109
Segment Type: other
Provision Reference: 
Character Range: 92896–95537

Δt = VCHSS x NWP /1000 x ((-0.028 x NWP +5.5) x Rs – 0.3) – 2.6 x Rs
where Rs = Ps / NWP, Ps is the pressure range of the pressure sensor (MPa), NWP is the Nominal Working Pressure (MPa), VCHSS is the volume of the compressed storage system (L), and Δt is the time interval (min).
5.1.3.                        If the value of Δt is less than 60 minutes, Δt is set to 60 minutes.
5.2.                              The initial mass of helium in the storage system is calculated as follows:
Po' = Po x 288 / (273 + T0)
ρo' = –0.0043 x (P0')2 + 1.53 x P0' + 1.49
Mo = ρo' x VCHSS
5.3.                              The final mass of helium in the storage system at the end of the time interval, Δt, is calculated as follows:
Pf' = Pf x 288 / (273 + Tf)
ρf' = –0.0043 x (Pf')2 + 1.53 x Pf' + 1.49
Mf = ρf' x VCHSS
where Pf is the measured final pressure (MPa) at the end of the time interval, and Tf is the measured final temperature (°C).
5.4.                              The average helium flow rate over the time interval is therefore:
VHe = (Mf-Mo) / Δt x 22.41 / 4.003 x (Ptarget/ Po)
where VHe is the average volumetric flow rate (NL/min) over the time interval and the term (Ptarget/Po) is used to compensate for differences between the measured initial pressure (Po) and the targeted fill pressure (Ptarget).
5.5.                              Conversion of the average volumetric flow of helium to the average hydrogen flow is done with the following expression:
VH2 = VHe / 0.75
where VH2 is the corresponding average volumetric flow of hydrogen.

6.                                   Post-crash concentration measurement for enclosed spaces
6.1.                              Post-crash data collection in enclosed spaces commences when the vehicle comes to a rest. Data from the sensors installed in accordance with paragraph 3.2. of this annex 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.

Annex 7

Impact reference line
Figure 7-1
Vehicle to be impacted on left side (overhead plan view)
Figure 7-2
Vehicle to be impacted on right side (overhead plan view)

Annex 8

Impact angle
Figure 8-1
Left side impact (overhead plan view)
Figure 8-2
Right side impact (overhead plan view)

Annex 9

Pitch and roll angle references
Figure 9-1
Example of a linear reference connecting two reference points on a left door sill
Figure 9-2
Example of a linear reference connecting two reference points on a rear body

Annex 10