A prover is a device with a “known traceable volume” designed to calibrate or prove a liquid flow meter’s accuracy and repeatability under actual operating conditions. Provers are used to calibrate and verify the accuracy and repeatability of both volumetric and mass flow meters with traceability.

Hydrocarbon liquid flow through pipelines needs frequent verification to ensure it is being transported under the right conditions. Flow meters that ensure the proper measurement of pipeline liquids may become faulty with prolonged use and give misleading performance monitoring and oil and gas measurements.

In custody transfer or allocation measurement applications, it is common practice to periodically prove liquid meters in the field. This is done to reduce uncertainty and maintain accuracy for fiscal measurement, establish meter factors at working conditions, and determine meter factors for different fluids. The measurement application or the customer contract generally determines the frequency at which it is proved