Patent ID: 8915115
Filing Date: 2014-12-23
Classification: G01F

Abstract:
1. A piston prover comprising a measurement cylinder having an upstream end through which a fluid flows in and a downstream end through which the fluid flows out; a hydraulic cylinder coupled with the downstream end of the measurement cylinder; a measuring piston that moves a predetermined distance L from upstream toward downstream through the measurement cylinder during a measurement due to a fluid flown from the upstream end to eject a reference volume of fluid; and a piston rod that is movably accommodated in the hydraulic cylinder, wherein the measuring piston and the piston rod are separately constructed, and when returning the measuring piston to a predetermined upstream measurement standby position, the piston rod moves the measuring piston from downstream to upstream to set the measuring piston at the predetermined measurement standby position, and thereafter only the piston rod is moved from upstream to downstream and is accommodated in the hydraulic cylinder.