First, the concept of pressure in the pressure gauge
The concept of pressure here actually refers to the physical pressure, that is, the amount of pressure per unit area.
Absolute pressure: The pressure above the absolute pressure zero, based on the absolute pressure zero.
Positive pressure: A pressure above atmospheric pressure based on atmospheric pressure.
Negative pressure (vacuum): A pressure below atmospheric pressure based on atmospheric pressure.
Differential pressure: The difference between the two pressures.
Gauge: A pressure greater or less than atmospheric pressure based on atmospheric pressure.
Pressure gauge: A gauge used to measure less than or greater than atmospheric pressure based on atmospheric pressure.
Second, the pressure gauge
In the process of industrial process control and technical measurement, mechanical pressure gauges have become more and more widely used due to the high mechanical strength and convenient production of elastic sensitive components of mechanical pressure gauges.
The elastic sensitive element in the mechanical pressure gauge is elastically deformed as the pressure changes. Mechanical pressure gauges use spring tubes (Bourdon tubes), diaphragms, bellows and bellows and other sensitive components and are classified accordingly. The measured pressure is generally considered to be relative pressure. Generally, the relative point is selected as atmospheric pressure. The elastic deformation of the elastic element under the pressure of the medium is amplified by the gear transmission of the pressure gauge, and the pressure gauge displays a relative value (high or low) with respect to atmospheric pressure.
The pressure value in the measurement range is displayed by the pointer, and the indication range of the dial is generally 270 degrees.
