All guides

• How to choose an inspection level: I, II, III and S-1 to S-4

  What the seven inspection levels do, in the words of the sampling standard: level II is the normal one, I and III trade discrimination for sample size, and S-1 to S-4 keep samples small at a higher risk.

• How to read an AQL table, step by step

  Reading an AQL table in three steps: lot size and inspection level to a code letter, code letter and AQL to a sample size with Ac and Re, and what to do when you land on an arrow.

• What AQL 2.5 means, with the numbers from the table

  AQL 2.5 read from the table: the sample size, acceptance number and rejection number for every lot size at general inspection level II, and what the 2.5 does and does not promise.

• What is AQL? The definition in the sampling standard

  What AQL means in acceptance sampling, read from the definition in MIL-STD-105E: a limit on the process average over a series of lots, not a promise about any single lot.