In the process of industrial process control and technical measurement, mechanical pressure gauges are becoming increasingly widely used due to the high mechanical strength and convenient production characteristics of their elastic sensing elements.

So how to understand the pressure in a pressure gauge? The concept of pressure here actually refers to the pressure intensity in physics, which is the magnitude of pressure exerted on a unit area. Absolute pressure: pressure above the absolute pressure zero point, based on the absolute pressure zero point as a benchmark. Positive pressure: pressure above atmospheric pressure, based on atmospheric pressure as a benchmark. Negative pressure (vacuum): pressure below atmospheric pressure, based on atmospheric pressure as a benchmark. Differential pressure: the difference between two pressures. Gauge pressure: pressure above or below atmospheric pressure, based on atmospheric pressure as a benchmark. Pressure gauge: an instrument used to measure pressures below or above atmospheric pressure, based on atmospheric pressure as a benchmark.

In addition, in industrial process control and technical measurement, mechanical pressure gauges are becoming increasingly widely used due to their high mechanical strength and convenient production characteristics of the elastic sensing elements.

The elastic sensing element in a mechanical pressure gauge undergoes elastic deformation as pressure changes. Mechanical pressure gauges employ sensing elements such as Bourdon tubes, diaphragms, capsule elements, and bellows, categorized accordingly. The pressure measured is generally considered relative pressure, with the reference point typically set at atmospheric pressure. The elastic deformation of the elastic element under the influence of the medium's pressure is amplified by the gear transmission mechanism of the pressure gauge, which then displays the relative value (higher or lower) relative to atmospheric pressure. The pressure value within the measurement range is indicated by the pointer, and the dial scale typically spans 270 degrees.

It is understood that pressure gauges can be classified based on their measurement accuracy, indicated pressure, measurement range, etc. Specifically, pressure gauges can be divided into precision pressure gauges and general pressure gauges according to their measurement accuracy. The measurement accuracy levels of precision pressure gauges are respectively 0.1, 0.16, 0.25, and 0.4; while the measurement accuracy levels of general pressure gauges are respectively 1.0, 1.6, 2.5, and 4.0.

Pressure gauges are categorized into general pressure gauges, absolute pressure gauges, and differential pressure gauges based on the reference pressure they indicate. General pressure gauges use atmospheric pressure as the reference; absolute pressure gauges use absolute pressure zero as the reference; and differential pressure gauges measure the difference between two measured pressures.

Pressure gauges are categorized into vacuum gauges, pressure-vacuum gauges, micropressure gauges, low-pressure gauges, medium-pressure gauges, and high-pressure gauges based on their measurement ranges. Vacuum gauges are used to measure pressure values less than atmospheric pressure; pressure-vacuum gauges are used to measure pressure values both less than and greater than atmospheric pressure; micropressure gauges are used to measure pressure values less than 60,000 Pa; low-pressure gauges are used to measure pressure values ranging from 0 to 6 MPa; medium-pressure gauges are used to measure pressure values ranging from 10 to 60 MPa; and high-pressure gauges are used to measure pressure values exceeding 100 MPa.

The casing of the shock-resistant pressure gauge is made into a fully sealed structure, and damping oil is filled inside the casing. Due to its damping effect, it can be used in measurement sites with vibrations in the working environment or pulsations in medium pressure (load). Pressure gauges with electric contact control switches can achieve signaling alarm or control functions, while pressure gauges with remote transmission mechanisms can provide the electrical signals required in industrial engineering (such as resistance signals or standard DC current signals).

In addition, the isolator (chemical seal) used in diaphragm gauges can isolate the measured medium from the instrument through the isolating diaphragm, facilitating the measurement of pressure in strongly corrosive, high-temperature, and easily crystallizing media.