The apparatus comprises of two units: the manometer and gauge assembly and the calibration of a pressure gauge assembly. During test, calibration weights are placed onto the loading platform, which is an integral part of the piston assembly. All air is expelled from the system through a purge hole in the upper part of the cylinder. The internal mechanism of the gauge is clearly visible through the transparent dial.
The apparatus has been designed to allow the suction pressure or delivery pressure of a diaphragm pump to be measured on sloping or vertical manometers and Bourdon gauges, for comparison; and to investigate the calibration and internal workings of a Bourdon gauge.
