1.1 This guide is intended to assist laboratories in maintaining precision and controlling bias in testing. It includes statistical procedures for detecting lack of control, changes in calibration constants, and in operator technique. Suggestions are given for the correction of some out of control situations.

1.2 This guide includes the following topics:

1.3 This standard does not give all of the details for preparing statistical quality control charts or the statistical tests used to interpret them, but such information may be found easily in a number of publications.