3.1 General

A pipe prover is a pipe or cylinder whose volume is used to verify and/or calibrate flow measuring systems for liquids. A process of calibration is accomplished by a displacer (usually a sphere or piston) passing through the pipe that actuates a pair of position detectors defining the calibrated section within a certain time. The known volume of this section (base volume) is used as a standard to determine the instrumental error of the measuring system which is connected to the prover. The measured volume is corrected for the errors due to the differences in temperature and pressure of the liquid from the reference condition. The travel time between the detectors is used to determine the flowrate.