Hydraulic gauges (hydraulic pressure gauges) are mainly classified according to measurement range, internal structure/components, functional characteristics, and accuracy level:
1. Classified by measurement range (range)
Micro pressure gauge: measuring range less than 0.1 MPa (<100 kPa).
Low pressure gauge: measuring range between 0.1 MPa and 6 MPa.
• Medium pressure gauge: The measurement range is between 10 MPa and 60 MPa.
High pressure gauge: The measurement range is between 60 MPa and 600 MPa.
Ultra high pressure gauge: measuring range greater than 600 MPa.
2. Classify by internal pressure sensing components
Bourdon tube (C-shaped spring tube) hydraulic gauge: The most common type, which uses the principle that an elliptical cross-section C-shaped spring tube tends to circular and undergoes elastic deformation under pressure to indicate pressure.
Diaphragm hydraulic gauge: uses the elastic deformation of the diaphragm to measure pressure, suitable for high viscosity, granular or corrosive media.
Bellows hydraulic gauge: commonly used for measuring lower pressures, with high sensitivity.
3. Classify by function and filling liquid
Ordinary hydraulic gauge: The internal structure is dry, without filling fluid, suitable for environments without severe vibration and corrosion.
• Shock resistant hydraulic gauge (filled pressure gauge): The case is filled with damping fluid such as silicone oil or glycerin, which can effectively absorb mechanical vibration and pressure pulsation, protect the internal movement, and stabilize the pointer reading.
Diaphragm hydraulic gauge: By using an external isolation diaphragm device, it prevents highly corrosive, crystalline, and high viscosity liquids from directly entering the gauge.
Electric contact pressure gauge: equipped with an electric contact switch device, when the pressure reaches the set upper or lower limit, it can automatically send an electrical signal to achieve alarm or automatic control.
4. Classified by measurement accuracy level
Precision hydraulic gauge: High accuracy level, commonly used levels include 0.1, 0.16, 0.25, and 0.4.
General (industrial) hydraulic gauges: low accuracy level, commonly used levels include 1.0, 1.6, 2.5, 4.0