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Division 3.9.2 PDP calibration calculations

United Kingdom

Original text. Later amendments are not shown.

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:

  1. (a)

    PDP volume pumped per revolution, V rev (m3/rev):

    V rev = ṅ ref – × R × T – in p – in × ƒ – n PDP (7-137)

    where:

    ṅ – ref
  2. mean value of reference molar flow rate [mol/s]

  3. R
  4. molar gas constant [J/(mol · K)]

  5. T – in
  6. mean inlet temperature [K]

  7. P – in
  8. mean inlet pressure [Pa]

  9. ƒ – n PDP
  10. mean rotational speed [rev/s]

  • (b)

    PDP slip correction factor, K s [s/rev]:

    K s = 1 ƒ – n PDP × p – out − p – in p – out (7-138)

    Where:

    ṅ – ref
  • mean reference molar flow rate [mol/s]

  • T – in
  • mean inlet temperature [K]

  • P – in
  • mean inlet pressure [Pa]

  • P – out
  • mean outlet pressure [Pa]

  • ƒ – n PDP
  • mean PDP revolution speed [rev/s]

  • R
  • 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 ƒ – n PDP :

    Table 7.4
    Example of PDP calibration data
    ƒ – n PDP [rev/min] ƒ – n PDP [rev/s] a 1 [m3/min] a 1 [m3/s] a 0 [m3/rev]
    755,012,5850,430,84050,056
    987,616,4649,860,831– 0,013
    1 254,520,948,540,8090,028
    1 401,323,35547,300,7883– 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).