Division 3.9.2 PDP calibration calculations
United Kingdom
For each restrictor position, the following values shall be calculated from the mean values determined in point 8.1.8.4 of Annex VI, as follows:
- (a)
PDP volume pumped per revolution, V rev (m3/rev):
(7-137) where:
Rmean value of reference molar flow rate [mol/s]
molar gas constant [J/(mol · K)]
mean inlet temperature [K]
mean inlet pressure [Pa]
mean rotational speed [rev/s]
- (b)
PDP slip correction factor, K s [s/rev]:
(7-138) Where:
mean reference molar flow rate [mol/s]
mean inlet temperature [K]
mean inlet pressure [Pa]
mean outlet pressure [Pa]
Rmean PDP revolution speed [rev/s]
molar gas constant [J/(mol · K)]
- (c)
A least-squares regression of PDP volume pumped per revolution, V rev, versus PDP slip correction factor, K s, shall be performed by calculating slope, a 1, and intercept, a 0, as described in Appendix 4;
- (d)
The procedure in subparagraphs (a) to (c) of this point shall be repeated for every speed that PDP is operated;
- (e)
Table 7.4 illustrates these calculations for different values of :
Table 7.4 Example of PDP calibration data [rev/min] [rev/s] a 1 [m3/min] a 1 [m3/s] a 0 [m3/rev] 755,0 12,58 50,43 0,8405 0,056 987,6 16,46 49,86 0,831 – 0,013 1 254,5 20,9 48,54 0,809 0,028 1 401,3 23,355 47,30 0,7883 – 0,061 - (f)
For each speed at which the PDP is operated, the corresponding slope, a 1, and intercept, a 0, shall be used to calculate flow rate during emission testing as described in point 3.6.3(b).