Pressure measuring instruments

All pressure measuring instruments are classified according to several criteria:

By type of measured pressure: manometers, manometers, manometers, manometers, micromanometers, drawbars, drawbars, barometers, differential manometers.

Manometers — These are instruments used to measure gauge or absolute pressure (difference in pressure). The «zero» of the manometer is at the level of atmospheric air pressure.

Vacuum gauges are used to measure the pressure of rarefied gases.

A manovacuum meter allows you to determine the overpressure and rarefaction of the gas.

Formerly measure a small overpressure (not more than 40kPa), gravimeters — a small vacuum gauge.

Differential pressure gauges determine the difference in pressure at two points.

Micromanometers — differential manometers for determining small pressure differences.

Barometers determine atmospheric air pressure.

According to the principle of action: liquid, deformation (spring, sleeve, diaphragm), deadweight, electrical and other devices.

Liquid manometers consist of communication vessels, the pressure is determined by one or more levels. In deformation manometers, the pressure is determined by the deformation or elastic force of a deforming element — spring, membrane, sleeve. In deadweight testers, the desired pressure value is determined by balancing the mass of the weights and the piston. Electric pressure gauges operate on primary pressure transducers.

By appointment: general technical for pressure measurement in technological processes and verification standard.

Accuracy class: from 0.4 to 4.0. This indicator characterizes the measurement error of the device.

According to the characteristics of the measured medium: general technical, corrosion resistant, vibration resistant, special, oxygen, gas.

Special manometers are used for viscous and crystallizing substances, as well as substances that contain solid particles.

In addition to the above, pressure measuring instruments differ in the limit (range) of measurements, the degree of protection against water (eight degrees), the type of protection against external objects (six degrees), the degree of vibration resistance, degree of resistance to humidity and temperature (11 groups).

Manometers

Pressure gauges and pressure gauges are designed to withstand short-term overload.

On the dial of the device are marked the scale markings, pressure units, minus sign for vacuum pressure, mounting position of the device, accuracy class, name / designation of the medium, sign of the state register, trademark of the manufacturer.

Examples of the use of electrical contact pressure gauges in electrical circuits, see here: Automation of pumps and pumping stations