Understanding the working principle of pressure measurement is important. This article will walk you through the different kinds of pressure measurement and explain why a pressure gauge needs calibration.
What is pressure measurement?
Speaking about pressure measurement, it is essential to know what is the definition of pressure. In short, pressure is a force exerted in an area. But how do we measure it will depend on what kind of pressure we want to measure.
There are three kinds of pressure measurement and different devices to measure each: absolute, gauge, and differential pressure.
Pressure measurement devices
There is a multitude of pressure devices available for measuring different types of pressure or specialized for different applications. Some of them measure other variables as well.
If you would like to know more about pressure measurement devices, we have articles respectively on pressure transmitters, differential pressure transmitters, pressure transducers, pressure sensors, and pressure gauges. Take your pick!
Pressure gauge calibration
Calibration is the procedure of comparing a reference with a known error margin against a device (for example a pressure gauge) under test. If the device doesn’t match the reference, then we adjust it to match, or at least come close, the desired measuring accuracy.
The reference measurement instrument must be more accurate than the pressure gauge to be calibrated, and it must also be traceable. To calibrate a pressure gauge, we will need to check the values throughout the entire measuring range, zero point, intermediate values, and the full-scale value.
Following this, we can arrive at two scenarios:
- Deviation within the manufacturer’s specifications, where the calibration certificate confirmation is required
- Deviation out of specifications, where adjustments are needed to ensure that we can easily use the sensor again
Depending on the standards we want to use, we can differentiate between 3 similar cases:
Why do pressure gauges and other pressure devices need to be calibrated?
Almost all sensors, gauges and meters are subject to drift. Drift means that the instrument slowly becomes less accurate. It means that there might be quality problems with the products or there might also incur serious safety issues. This will finally result in an increased cost of the processes. This is the reason why we should schedule calibrations in our plants for every device. Pressure gauges are exposed to different influences (aggressive media, changing conditions, etc.), which makes them especially prone to drift.
To know more about pressure measurement and calibration, you can get in touch with our engineers and we will be happy to help.