Measurement of flow to flares is important from accounting, mass balance, energy conservation, emissions reduction, and regulatory perspectives. Flares are safety relief systems that typically receive highly unpredictable rates of flow and varying compositions, and for safety reasons do not often lend themselves to being taken out of service to accommodate measurement concerns, even for short periods.

The standard addresses measurement of flow to flares, and includes:
- application considerations;
- selection criteria and other considerations for flare meters and related instrumentation;
- installation considerations;
- limitations of flare measurement technologies;
- calibration;
- operation;
- uncertainty and propagation of error;
- calculations.

The scope of this standard does not include analytical instrumentation.

This second edition includes discussion on using tracer technology and incorporates reference to API MPMS Chapter 22.3, Testing Protocol for Flare Gas Metering, another API standard that supports industry safety, sustainability, and emission reductions.