The spring tube of a general pressure gauge is a tubular spring that has a certain cross-sectional shape (two commonly used flat circles and approximately oval shapes), is bent into a "C" shape, and can meet certain elastic requirements. If the spring tube is too small, it will affect the accuracy rating of the pressure gauge.
2. If the indication value of the pressure gauge exceeds the allowable error, the indication adjustment screw of the gauge should be adjusted. If the gauge does not have an indication adjustment screw, the gauge can only be judged as unqualified.
3. The division numbers and symbols on the dial of the pressure gauge should be complete and clear. The dial graduation scales should be evenly distributed, the central angle of the bag is generally 270°, the pointer of the pressure gauge should extend into the graduation line, and the width of the pointer indicating end should not be greater than 1/5 of the minimum graduation interval. The distance between the pointer and the plane of the index plate should be within the range of 1 to 3mm. If the outer diameter of the case is more than 200mm (including 200mm), the distance between the pointer and the plane of the index plate should be within the range of 2 to 4mm.
4. The case of the pressure gauge should be able to protect the internal parts from contamination, the pressure gauge should be equipped with safety holes, and there should be dust-proof devices on the safety holes.
5. For pressure gauges with stop pins, the pointer should be close to the stop pins when there is no pressure or vacuum, and the "shrinkage" should not exceed the specified allowable error.
6. Digital pressure gauge. It depends on the rationality of the overall structure, the selected materials, the aging process of electronic components, and long-term stability.
