Pressure gauges are used as particularly versatile measuring instruments in industrial, chemical and process engineering. The manometers serve primarily to display a physical pressure in a gaseous medium such as air. In addition, however, pressures in other units in the form of liquids such as water and oils can be measured very precisely. In principle, a distinction is made between direct and indirect measuring devices in the case of pressure gauges. In the case of direct pressure gauges, the definition of the measurand is based on a physical quantity such as the prevailing atmospheric pressure. The indirect pressure gauges derive their measurement method from the derivation of the measured quantities by other physical effects. In addition, however, there are special pressure gauges such as barometers and various pressure sensors
Application areas for pressure gauges
In many areas of industrial and process engineering, a defined display of print sizes is required. It is possible to measure general fluids such as water or oils in the hydraulic application or compressed air in the respective application areas. Special applications for pressure gauges can also be found in chemistry. In addition, the measuring instruments are also differentiated according to pressure ranges and divided into low-pressure, high-pressure or vacuum measuring instruments. The display resolution and the accuracy is divided into different areas of the general utility meters and the precise precision meters.
Different measuring methods
Another important aspect is the measuring method used for pressure gauges. In particular, mechanical, electrical and mechatronic measuring methods have become established here. In the case of indirect measuring instruments, secondary physical quantities are usually used for the measurement. These can be derived from the compression of gases, the friction of measuring bodies or the temperature line, for example, of a gas and displayed. In direct measuring instruments, for example, the force on a defined surface serves as a measured variable. This procedure is usually found again with piston or liquid manometers. In addition to the standard displays for single measurements, there are also differential pressure manometers. The determination of the measured variable in this case so-called plate spring measuring devices is used. A deformable spring determines the difference between two opposite measuring chambers.