Example 4 - Double Sampling

Q 

Tightened inspection is in use, AQL is 10, the batch size is 2000, double inspection and the inspection level is II. What is the double sampling plan?

A 

1. Set the batch size (1201 to 3200) in the upper window

2. Look next to the Inspection Level II to find Code Letter K.

3. Next turn over the AQL Inspector's Rule and set the AQL window to 10, looking under Code Letter K in Tightened inspection we find a first sample size of 80, with an acceptance number of 9 and a rejection number of 14.

4. If the number of defects is 9 or less accept the batch the inspection of the batch is complete.

5. If the number of defects is 14 or more reject the batch and inspection of the batch is complete.

6. If the defect count is between 9 and 14 (10 to 13) continue to the second inspection. Take second sample of 80 pieces.

7. Add the defects in found the first and second samples.

8. If the combined defect count is 23 or less accept the batch.

9. If the combined defect count is 24 or more reject the batch.