Cause analysis of dial movement
A user returned two pressure gauges, reflecting that the two pressure gauges were installed on the user’s product-liquid oxygen tank. Everything was normal during the test of the thermal resistance, but after the product was in the hands of the user, the pressure gauge was often operated. Not working. When the meter was taken to the workbench for calibration, the meter was okay.
These two watches are used in two places, and there are two different situations. It seems that there are some abnormalities, but the abnormality must have the cause of the abnormality. After disassembling the instrument, it was found that the abnormal stainless steel pressure gauge was caused by the movement of the instrument dial. Under normal circumstances, the needle library of the pressure gauge should be in the middle of the center hole of the dial. If the dial moves to the left and right, when the movement is too large, the center hole of the dial will rub against the needle library, causing friction. In severe cases, it will hinder the operation of the pointer and cause pressure. The case where the watch pointer does not work.
Why does the dial appear to move?
1. The amount of frame between the fixed gaps on both sides of the dial and the fixed blocks on both sides of the ring is too large, which creates objective conditions for the left and right movement of the dial.
2. The cover is not pressed tightly, and the screws of the thermal resistor and the cover are not tightened, resulting in an unstable fixing of the dial ring to the dial.
3. In the process of transportation, the hydraulic tank may tilt, and the sudden vibration will cause the dial to move left and right. If the vibration is large, the deviation of the dial will be greater, and the inner side of the center hole of the dial may withstand the pointer needle. On the outside of the library, when pressurized, the stainless steel pressure gauge will appear "the pressure gauge does not work" phenomenon.
