Reliable measured values thanks to the right accuracy class of pressure gauges

Pressure gauges are components for measuring and displaying the pressure of a medium in the process industry and are available in different accuracy classes. The accuracy class of pressure gauges indicates the maximum deviation between the displayed measured value and the actual value of the measured pressure. It therefore indicates how accurately the pressure gauge can measure and display the pressure. The accuracy class is given as a percentage of the full scale value and is shown accordingly on the dial.

For example, if a pressure gauge has an accuracy class of 1.0% and a measuring range of 0-10 bar with a full scale value of 10 bar, the pressure measurement must not deviate by more than 1.0% x 10 bar = 0.1 bar. A display of 5.9bar or 6.1bar on the dial with an actual pressure of 6bar is therefore within the tolerance of the pressure gauge.

The accuracy of pressure gauges is already defined by the nominal size of the device. Put simply, the smaller the housing of the device and therefore the smaller the measuring element, the less accurate the measurement and the higher the accuracy class. Pressure gauges below the nominal size of 100mm usually have an accuracy of 1.6% or 2.5%. From a nominal size of 100mm, the accuracy is 1.0%. Even higher accuracies of 0.6%, 0.25% or even 0.1% can be realised with precision gauges from a housing size of 160mm or 250mm.

In order to achieve the most accurate measurement possible with the pressure gauge, the measuring range is also important in addition to selecting the appropriate accuracy. Ideally, the pressure to be measured should be between 60% and 75% of the display range. The accuracy is highest in this range. For a measurement of 7 bar, for example, a 0-10 bar device should be selected.

TRI-MATIC pressure gauges are available customised to your requirements for many sectors and industries. Each pressure gauge is subjected to a 100% function and accuracy test at the factory. In this way, we guarantee that the measuring devices comply with the declared accuracy class on delivery.

Benefit from our pressure gauges for reliable measured values. Contact us at +41 41 780 22 22 or info@tri-matic.ch.