Document ID: chunk:federal_register_of_legislation:F2011C00805:reg:32:p8
Version: federal_register_of_legislation:F2011C00805
Segment Type: reg
Provision Reference: reg 32 (pt 8/8)
Character Range: 126507–128520

to the increased sample.

        4.  PROCEDURE TO BE FOLLOWED WITHOUT SEPARATE EVALUATION OF OUTLYING EMITTERS IN THE SAMPLE

        4.1. With a minimum sample size of three vehicles, the sampling procedure is set so that the probability of a batch passing a test with 40 per cent of the production defective is 0.95 (producer's risk = 5 per cent) while the probability of a batch being accepted with 75 per cent of the production defective is 0.15 (consumer's risk = 15 per cent).

        4.2. For each of the pollutants given in the table of paragraph 5.3.1.4. of this Regulation, the following procedure is used (see Figure 4/2 below).

        where:

            L = the limit value for the pollutant,

            xi = the value of the measurement for the i-th vehicle of the  sample,

            n = the current sample number.

        4.3. The test statistic quantifying the number of non-conforming vehicles, i.e. xi > L, is computed for the sample.

        4.4.  Then:

            (i) If the test statistic does not exceed the pass decision number for the sample size given in the following table, a pass decision is reached for the pollutant,

            (ii) If the test statistic equals or exceeds the fail decision number for the sample size given in the following table, a fail decision is reached for the pollutant,

            (iii) Otherwise, an additional vehicle is tested and the procedure is applied to the sample with one extra unit.

        In the following table the pass and fail decision numbers are computed in accordance with the International Standard ISO 8422:1991.

        5. A sample is regarded as having passed the test when it has passed both the requirements of paragraphs 3. and 4. of this Appendix.

        Figure 4/1

        In-service conformity checking – audit procedure

Table 4/1

TABLE FOR ACCEPTANCE/REJECTION SAMPLING PLAN BY ATTRIBUTES

Cumulative sample size (n)  Pass Decision number  Fail decision number