This part of ISO 2859 establishes LQ sampling plans and pro-cedures for inspection by attributes compatible with ISO 2859/1 that can be used when the switching rules given in ISO 2859/lare not applied, for example, when lots are of an isolated nature.
The plans in this part of ISO 2859 are indexed by a preferred series of limiting qualities (LQ) with a consumer's risk usually below 10 %, but always below 13 %. This method of indexing permits the "ad-hoc" procedure mentioned in sub-clause 12.6 of ISO 2859/1 to be implemented as a standard procedure.
NOTE — The plans in ISO 2859/1 are indexed by a preferred series of AQL values and irjspection levels. During the inspection of a continu-ing series of lots the application of switching rules helps to ensure that the process average in that series of lots is kept below the specified AQL. Limiting quality does not have the same direct relationship with the process average (see 3.5.1).