There are many types of pressure gauges

   There are many types of pressure gauges, including not only general (ordinary) pointer indication type, but also numerical type; There are not only conventional types, but also special types; Not only contact type, but also remote transmission type; There are not only vibration resistant types, but also seismic resistant types; Not only diaphragm type, but also corrosion-resistant type.

   The pressure gauge series is complete. It not only has a regular series, but also a digital series; There are not only ordinary media application series, but also special media application series; There are not only switch signal series, but also remote transmission signal series, etc., all of which originate from practical needs and have successively formed a complete series. The specifications and models of pressure gauges are complete, and the structural types are complete.

   From the nominal diameter perspective, there are various sizes such as Φ 40mm, Φ 50mm, Φ 60mm, Φ 75mm, Φ 100mm, Φ 150mm, Φ 200mm, and Φ 250mm. From the perspective of installation structure types, there are direct installation type, embedded type, and convex type. Among them, embedded type is further divided into radial embedded type and axial embedded type, and convex type is also divided into radial convex type and axial convex type. Direct installation type is divided into radial direct installation type and axial direct installation type. The radial direct installation type is the basic installation type, and generally refers to the radial direct installation type when the installation structure type is not specified. Axial direct installation type considers the stability of its own support and is generally only selected for pressure gauges with a nominal diameter less than 150mm.

   The so-called embedded and convex pressure gauges are commonly referred to as edge (mounting ring) pressure gauges. Axial embedded type refers to pressure gauges with a forward edge, radial embedded type refers to pressure gauges with a forward edge, and radial convex type (also known as wall mounted type) refers to pressure gauges with a backward edge.

   From the perspective of measurement range and range section, the positive pressure measurement range is divided into micro pressure range section, low pressure range section, medium pressure range section, high pressure range section, and ultra-high pressure range section.

   Each range section is further subdivided into several measurement ranges (instrument range); There are three types of negative pressure (vacuum gauge) in the negative pressure range (vacuum); A pressure gauge with a combination of positive and negative pressure is a type of pressure gauge that spans multiple measurement ranges. Its standard name is pressure vacuum gauge, also known as vacuum pressure gauge. It can measure not only positive pressure but also negative pressure.

   The accuracy classification of pressure gauges is very clear. Common accuracy levels include 4, 2.5, 1.6, 1, 0.4, 0.25, 0.16, 0.1, etc. The accuracy level should generally be marked on its dial, and there are corresponding regulations for its identification, such as "①" indicating that its accuracy level is level 1. For some pressure gauges with very low accuracy levels, such as those below level 4, and some that do not require accurate pressure measurement and only need to indicate the pressure range, such as pressure gauges on fire extinguishers, the accuracy level can be omitted.