Dimensional Characterization and Effective Area Estimation of the 35 mm Piston/Cylinder Assembly -PG0806

Piston/cylinder assemblies are widely used in the calibration of pressure measuring equipment whose principle of operation is to generate pressure by positioning non-standard weights which generate radial forces when compressing the fluid. The dimensional characterization of the piston/cylinder assemblies is fundamental to the realizations the pressure measurement made with piston/cylinder assemblies. There diameter, straightness and roundness measurements were made for the PG 0806 of the pressure laboratory of the INM - Colombia, both for the cylinder and the piston itself. To do this measurement the Brown & Sharpe coordinate measuring machine (CMM) of the dimensional laboratory of the INM was used. With the measuring method described, we were capable to measure the effective area with a relative uncertainty about 9.7x10-5.