Pressure gauges are one of the most commonly used instruments in industrial production. They are mainly tested with elastic components as sensitive parts and indicate instruments that are different from ambient pressure. Pressure gauges are widely used in various industries, so it is very important to learn to identify the quality of pressure gauges.
First, the appearance check
1. Before getting the pressure gauge, we should carefully observe the outer packaging and whether the packaging box is clear and clear.
2. After getting the pressure gauge, you should carefully observe whether the appearance of the pressure gauge is even and smooth, no rust, and the weld should be smooth and free of cracks.
3. Whether the dial reading part is clear and the transparent cover is stained.
4. Pressure gauge with stop pin, when there is no pressure, the pointer should be close to the stop pin. For pressure gauges without a stop, the pointer should be at zero when there is no pressure.
5. Filling pressure gauge, the liquid should be clear and transparent without impurities, and its liquid level should be located 1/3 to 1/4 above the center of the case.
Second, the meter
1. Select the appropriate standard to verify its accuracy.
3. Verification of indication error, return error, and tapping displacement
1. The indication error, the indication of the pressure gauge is carried out according to the index line marked with numbers, and the gradual smooth boost (or step-down) is detected. When the index reaches the detection upper limit, the pressure source is cut off, withstand voltage for three minutes, then Check back in the reverse order of the original verification point.
2. Return error, the absolute value of the specified allowable error at the same point check, at the boost (or buck) and buck (or boost) check.
3. Tap the displacement, check the timing of each verification point. At the step of boost (or buck) and buck (or boost), the indicator change caused by the light case is not greater than the absolute value of the specified allowable error. 1/2.
