1 The assembly of the pressure gauge components should be firm and not loose.

2 The newly manufactured pressure gauge should be uniform, smooth and without obvious peeling.

3 The pressure gauge should have a safety hole, and the safety hole must have a dustproof device. (The pressure gauge does not allow the measured medium to overflow outside the instrument)

4 The pressure gauge index plate shall have the following signs, manufacturing units or trademarks; product names; signs and numbers of measurement units and manufacturing licenses for digital measuring instruments. The vacuum gauge should have "-" or "negative" characters, and the accuracy grade is the serial number.

5 In the reading part, the watch glass should be colorless and transparent, and there should be no defects that hinder reading. The signs should be flat and clean, and all markings should be legible.

6 The pointer indicating end should cover 1/3~2/3 of the length of the shortest scale line, and the width of the pointer indicating end should not be greater than the width of the scale line.

7The accuracy levels are 1, 1.6, 2.5, and 4.

8 zero position, pressure gauge with stop pin. When there is no pressure or vacuum, the pointer should be close to the stop pin, and the "indentation" should not exceed the allowable error value specified in Table 1. Or in a vacuum, the pointer should be located at the zero mark, and the zero mark shall not exceed 2 times the absolute value of the allowable error specified in Table 1.