FM-1849-18 Dead Weight Apparatus

Experiments

  • Calibrating a Bourdon type pressure gauge.

Specification
   Pressure Gauge

  • Diameter: 6” or 150mm
  • Bourdon Tube Pressure Range: 0~400kN/m2 Pressure Least Count: 10kN/m2
  • Alternate Scale: PSI / bar

Description

Calibration is a process for detecting deviations in a  measuring instrument compared to a reference instrument  or universally accepted standard value. This observed  deviation is taken into account in the subsequent use of  the calibrated measuring instrument and adjusted if  necessary.

Dead Weight Pressure Calibrator is a device designed as an  introduction to the basics of checking and calibrating a  manometer (Pressure gauges/transmitter).  Dead Weight Pressure Calibrator apparatus consists of a  precision machined piston and cylinder assembly mounted  on leveling screws. A Bourdon gauge is supplied for  calibration.

A defined force is applied by loading the piston with dead  weights. The ratio of force / piston cross-sectional area  results in a defined test pressure. Hydraulic oil is used to  transfer the force. If the pressure in the system rises, the  force acts against the spring of the Bourdon tube pressure  gauge. The test pressure that is produced can be read on  the manometer’s dial. The Bourdon Tube mechanism of a pressure gauge working is clearly visible through the  transparent dial. Loading the calibrated piston manometer with weights produces a very accurate, reproducible  calibration pressure, which can be used to check and calibrate the manometer.

The weights supplied are added to the upper end of the piston rod which is rotated to minimize friction effects. The gauge  is thus subject to known pressures which may be compared with the gauge readings and an error curve drawn.