Improvements In The Determination Of Effective Area Through A Piston-Cylinder Pressure Calibration Chain

摘要

Since the mid-1980s, DH Instruments has maintained a pressure calibration chain made up of multiple, interconnected piston-cylinders both to assure the coherence of pressure measurements over the range of less than10 kPa to 500 MPa and as a vehicle to maintain traceability to national metrology institutes (NMIs). In 2001, a three year calibration chain maintenance cycle was completed. The results reflect changes made to the calibration chain that reduce the uncertainty in effective area over the covered range and thus the uncertainty in DHI's accredited scope of pressure. This paper summarizes the principles of the calibration chain, examines the improvements made over the past few years, and exposes the benefits realized. These benefits include lower uncertainty in effective area and pressure and better agreement in inter-laboratory comparisons with various standards laboratories around the world.