ABSTRACT
The terms calibration, verification, proving, and validation are first examined in this chapter.
Calibration involves comparing the meter under test with an accredited calibration rig while verification/proving is carried out periodically to verify the accuracy against a prover. And validation typically involves self-diagnostic programmes that indicate that the unit is performing as originally calibrated.
A comparison is made between volumetric and gravimetric calibration rigs and the need to correct for air buoyancy.
A number of provers are examined including open- and closed-tank provers, displacement pipe provers, piston provers, and master meters. Particular attention is paid to the use of captive small volume provers for use in mobile applications and how pulse interpolation is used to effectively increase the resolution of a pulsed output by estimating the fraction of a pulse missed at the beginning and the end of a test. We also look at why their use is precluded for use with both ultrasonic and Coriolis meters.
