Quality requirement

1. The spring tube of a general pressure gauge has a certain cross-sectional shape (commonly used are flat circles and approximate ellipses), bent into a "C" shape, and can meet certain elastic requirements as a tubular spring. If the spring tube is too small, it will affect the accuracy level of the pressure gauge.

2. If the reading of the pressure gauge exceeds the allowable error, the reading adjustment screw of the gauge should be adjusted. If the gauge does not have a reading adjustment screw, it can only be judged as unqualified.

3. The division numbers and symbols on the pressure gauge dial should be complete and clear. The dial dividing scale should be evenly distributed, with a center angle of generally 270 °. The pointer of the pressure gauge should extend into all dividing lines, and the width of the pointer indicating end should not exceed 1/5 of the minimum dividing interval. The distance between the pointer and the dial plane should be within the range of 1-3mm. For cases with an outer diameter of 200mm or more (including 200mm), the distance between the pointer and the dial plane should be within the range of 2-4mm.

4. A pressure gauge with a stop pin should have its pointer tightly against the stop pin when there is no pressure or vacuum, and the "grid reduction" should not exceed the specified allowable error.

5. The pressure gauge case should be able to protect the internal components from contamination, and the pressure gauge should be equipped with a safety hole with a dust-proof device.

6. The digital pressure gauge depends on the rationality of the overall structure, the selected materials, the aging process of electronic components, and long-term stability.