To Calibrate a Pressure Gauge Using a Dead Weight Pressure Gauge Calibrator

Apparatus

• Dead weight pressure gauge calibrator having the following main components,
• Cylinder
• Weights
• Leveling screws
• Spirit level
• Cylinder inlet
• A gauge to be calibrated
• Hydraulic bench

Concepts:

Calibration of guage:

To compare the values of an instrument with that of the standard ones is known as calibration of that instrument.

Pressure gauges:

The instruments with the help of which we measure the pressure are called as the pressure gauges.

Also Read: Calibration of Rectangular Notch | Other Fluid Mechanics Experiments

Absolute Pressure:

The pressure measured with reference to absolute zero is called as absolute pressure.

Gauge pressure:

The pressure measured with the atmospheric pressure is called as gauge pressure.

Vacuum pressure:

Negative gauge pressure is known as vacuum pressure.

Atmospheric pressure:

The pressure exerted by the atmosphere above us is known as the atmospheric pressure. Its standard values are given below.

Procedure:

• I placed the pressure gauge and calibrate assembly on bench top.

• I connected the inlet tube to the gauge manifold.

• A length of tube was connected to the calibrator drain and laid into the channel to prevent spillage of water on the bench top.

• The calibrator was leveled by the adjusting feel whilst observing the spirit level.

• I removed the piston and accurately determined its mass.

• I closed the control valve of the bench and open both cocks then I operated the pump starter and also open the control valve and admitted the water to the cylinder.

• After removal of air bubbles from the tube, I closed the cock along with flow control valve and switched of the pump.

• I noted the gauge readings corresponding to the piston mass of .5 kg.

• Then I added .5 kg mass each time and noted the corresponding gauge readings.

• Then I find out the Absolute gauge error by the following formula.

• Absolute gauge error = Pressure in cylinder – Gauge reading

• Then I find out the %age gauge error by the following formula.

• %Age gauge error = Absolute gauge error *100 / Pressure in cylinder

• Then I plotted a graph between %age gauge error and pressure in cylinder.