ASTM D7720 Statistical Alarm Limits

ASTM D7720 is the guide for statistically evaluating measurand alarm limits when oil analysis is used to monitor equipment and oil for fitness and contamination. Alarm limits are the thresholds that turn a result into “normal,” “watch,” or “act.” D7720 is about whether those thresholds are statistically honest — not about how to run D445 or D2272 on the bench.

This is a different job from ASTM D6299, which charts the measurement system. It is also not a substitute for D4378 or D6224, which define the in-service programs. Programs that copy a generic OEM table and never look at their own distribution are exactly the audience this guide was written for.

This page is original prose and is not a reproduction of the standard. Buy the official text from the ASTM store.

ASTM Standard at a Glance

Related software

This guide is cited by VeroOCM.

Where this guide shows up at Vero

D7720 is the statistical alarm-limit guide in the OCM standards library. It sits next to the instrument-QC practice (D6299) and the two in-service monitoring practices (D4378, D6224).

See VeroOCM for the platform that applies that logic to live results.