| 摘要 |
<p>Disclosed is a piston prover which enables smooth movement of a measuring piston through a measurement cylinder without applying more than necessary load to the measuring piston and which has a simplified structure with reduced parts count. The piston prover (1) includes the measurement cylinder (2) provided with an upstream end (3) and a downstream end (4); a hydraulic cylinder (12) coupled to the downstream end of the measurement cylinder (2); the measuring piston (9) which during measurement, a fluid drawn from the upstream end (3) causes to move by a predetermined distance from upstream towards downstream through the measurement cylinder (2) to displace a specified volume of fluid; and a piston rod (13) accommodated movably in the hydraulic cylinder (12). The measuring piston (9) and the piston rod (13) are separately constructed, in which to allow the measuring piston (9) to return to a predetermined upstream measurement standby position, the piston rod (13) moves the measuring piston (9) from downstream towards upstream to set the measuring piston (9) at the predetermined measurement standby position, and thereafter, the piston rod (13) is accommodated in the hydraulic cylinder (12).</p> |
