There are many kinds of pressure gauges, it is not only general (ordinary) pointer indicator type, and digital type; There are not only conventional types, but also special types; Not only has the contact type, also has the far transmission type; There are not only vibration resistant, but also seismic; Not only have diaphragm type, and corrosion resistant type.
Pressure gauge series complete. It has not only regular series, but also digital series; There are not only ordinary media application series, there are special media application series; There are not only switch signal series, but also remote transmission signal series and so on. They all originate from practical requirements and constitute a complete series successively.
The pressure gauge has complete specifications and types and perfect structure. From the nominal diameter, there are 40 mm, 50 mm Φ, Φ Φ 60 mm, 75 mm, 100 mm Φ Φ, Φ 150 mm, 200 mm, 250 mm Φ Φ, etc.
From the view of the installation structure type, there are direct installation type, embedded type and convex installation type, among which the embedded type is divided into radial embedded type and axial embedded type, and the convex type is also divided into radial convex type and axial convex type. Direct installation type, divided into radial direct installation type and axial direct installation type. Among them, radial direct installation type is the basic installation type. Generally, it refers to radial direct installation type when the installation structure type is not specified. Axial direct mounting considering the stability of its own support, generally only in the nominal diameter of less than 150mm pressure gauge selection. The so-called built-in and convex pressure gauges, we often say edge (installation ring) pressure gauges. Axial inlaid type both axial front side, radial inlaid type refers to the radial front side, radial convex type (also known as wall type) refers to the radial back side pressure gauge.
From the perspective of measurement area and measuring range, the positive pressure measurement area is divided into micro pressure measurement range, low pressure measurement range, medium pressure measurement range, high pressure measurement range and ultra-high pressure measurement range. There are three kinds of negative pressure in the negative pressure field (vacuum). The pressure gauge with positive and negative pressure linkage is a pressure gauge that spans the range of quantities. Its specification name is pressure vacuum gauge, also known as vacuum pressure gauge. It can measure not only positive pressure but also negative pressure.
The accuracy classes of pressure gauges are very clear. The common precision grade is 4, 2.5, 1.6, 1, 0.4, 0.25, 0.16, 0.1, etc. Accuracy grade should be marked on its dial in general, and its mark has corresponding provisions, such as "1" means its accuracy grade is 1. For some pressure gauges with low accuracy grade, such as those under grade 4, and some that do not need to measure the exact pressure value, only need to indicate the pressure range, such as the pressure gauge on the fire extinguisher, can not mark the accuracy grade.
The above contents are sorted out according to the problems students encounter in the actual work, for reference, please timely communicate and correct any problems.
