Safety First With Industrial Equipment and Supplies

Six Mistakes That Need To Be Avoided When Pressure Gauges Are Calibrated

24 January 2019

Lucille Palmer

At many industrial facilities, pressure gauges are essential to keeping equipment productive and safe. Regular calibration of gauges is essential to ensuring that they continue to function properly and accurately.

It's important to avoid the following six mistakes during pressure gauge calibration to ensure that calibrations are accurate:

Calibrating a contaminated gauge without cleaning it out

Contamination is a significant problem when it comes to gauge accuracy. Unfortunately, dirt and residue can easily get into calibration equipment that is used in industrial environments.

Before calibration, gauges should be inspected and cleaned out as necessary. If you're using gas gauges, you can minimize contamination issues by choosing a model that includes a moisture and dirt trap. However, you'll have to be particularly thorough with cleanings if you are using a liquid pressure gauge.

Failing to inspect piping for leaks

During every calibration, it's important to make sure that no leaks have developed or are developing in the piping of the gauge.

In fact, it's best to perform a leak test periodically to make sure there are no leaks. A leak test involves pressurizing the system and allowing the pressure to stabilize. If the pressure goes down significantly on its own, it's an indication that there is a leak.

Not accounting for differing heights between the gauge and the calibration equipment

When liquid pressure gauges are used, height differences between the gauge and the calibration equipment can create accuracy issues due to hydrostatic pressure. It's best to calibrate when the gauge and equipment are at the same height to avoid errors due to the pressure media in the piping.

Not exercising the gauge before it is calibrated

It's a good idea to exercise the gauge a bit before calibration to minimize friction. The gauge can be exercised by supplying maximum pressure to the gauge and leaving it for a few moments and then venting the pressure out. It's best to do this a few times before calibration for maximum accuracy.

Being fooled by adiabatic effect during calibration

Adiabatic effect occurs when temperatures inside a gas medium rise quickly along with a sudden increase in pressure. This will cause the pressure to read excessively high.

The way to avoid inaccuracies due to adiabatic effect is to make sure you let pressure stabilize after any sudden increases in pressure before calibration.

Calibrating gauges used at high pressures with air rather than liquid pressure media

Pressure gauges are generally calibrated with a pressure media of either gas or liquid. If you are working with very high pressure applications with your gauges, you should always be calibrating with liquid pressure media rather than gas. Liquids function more practically and safely as pressure media at higher pressures. 

Contact a pressure gauge distributor for more help.

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