How Accurate Are Pressure Gauges?

Pressure gauges are a critical tool for monitoring pressure in many types of industrial systems. They are also important in safety applications such as measuring hazardous media like oxygen, acetylene, or toxic and combustible gases. When working with such dangerous substances, it is imperative to choose a pressure gauge that has built in safety features including a blow-out device on the back of the scale to prevent leaks or bursts from damaging anyone standing behind the gauge.

The accuracy of a pressure gauge depends on the medium being measured and the method used to measure it. Different pressure gauges use different methods to read and display the measurement. These include the flexing of a diaphragm to deflect a needle, the movement of a piston to a dial indicator, or the attraction between magnets to move a pointer.

One of the earliest and most basic pressure gauges is the Bourdon tube gauge invented by Eugene Bourdon in 1849. It consists of a U-shaped tube half-filled with liquid, the end connected to the area of interest and the other exposed to atmospheric pressure or a reference vacuum. The liquid column rises or falls until the weight of the liquid counterbalances the differential pressure and causes the gauge to register an accurate reading.

Modern digital pressure gauges offer clear and easy-to-read displays that are more accurate than analog. They also feature international measurement units on their digital display and can record MIN/MAX settings for quick recall. They are often the preferred choice for corrosive liquids, gases, or high viscosity media. They are typically sealed to provide protection from impacts, pulsations, and vibrations.