Comparison of Piezo and Ball Copper Pressure Measurements in Closed Vessel System

Abstract

A series of Closed Vessel firings are carried out at different pressure levels in the range of 0 to 1800 kg/cm/sup 2/ covering the complete pressure range of ball copper and Marl 8 crusher gauge combination. The pressure are simultaneously measured by a piezo (tourmaline) gauge and the ball copper pressures are evaluated from the Tarage table for existing standard ball copper as required by U.K. ordnance, using suitable temperature corrections. The results indicated that the agreement between the piezo and ball copper pressures is generally very good. At the pressure levels of 600,1200 and 1800 kg/cm/sup 2/, the magnitudes of percentage deviation of ball copper pressures from piezo pressures are from 0.2 to 3.4, 2.6 to 4.2 and 2.0 to 4.6 respectively. The pressure recorded by ball coppers are found to be slightly on higher side compared to piezo pressure in nearly all the measurements.