Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:32
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 32
Character Range: 148414–150411

32                                                 − 2.112                  − 2.112

           Appendix 2 Procedure for production conformity testing when standard deviation is unsatisfactory or unavailable
A.2.1. This appendix describes the procedure to be used to verify production conformity for the emissions of pollutants when the manufacturer's production standard deviation is either unsatisfactory or unavailable.
A.2.2. With a minimum sample size of three engines the sampling procedure is set so that the probability of a lot passing a test with 40 per cent of the engines defective is 0.95 (producer's risk = 5 per cent) while the probability of a lot being accepted with 65 per cent of the engines defective is 0.10 (consumer's risk = 10 per cent).
A.2.3. The values of the pollutants given in paragraph 5.3. of this Regulation, after having applied the relevant DF, are considered to be log normally distributed and should be transformed by taking their natural logarithms. Let m0 and m denote the minimum and maximum sample size respectively (m0 = 3
and m = 32) and let n denote the current sample number.
A.2.4. If the natural logarithms of the measured values (after having applied the relevant DF) in the series are x1, x2, … xi and L is the natural logarithm of the limit value for the pollutant, then, define:

A.2.5. Table 3 shows values of the pass (An) and fail (Bn) decision numbers against current sample number. The test statistic result is the ratio  and shall be used to determine whether the series has passed or failed as follows:
 For m0 ≤ n ≤ m:
 (a) Pass the series if

 (b) Fail the series if

(c) Take another measurement if

A.2.6. Remarks
 The following recursive formulae are useful for calculating successive values of the test statistic:

Table 3
       Pass and fail decision numbers of Appendix 2 sampling plan
       Minimum sample size: 3
Cumulative number of engines tested (sample size)  Pass decision number An  Fail decision number Bn