At this point, first check whether the connection between the pressure gauge and the pressure gauge calibrator leaks oil. If there is no oil leakage and the calibrator is in good condition, it means there is leakage inside the spring tube, and the scale plate should be removed for further inspection.
1. The machine base itself has trachoma, which gradually leaks after long-term use. It is necessary to replace the machine base of the same specification, and it can be repaired by measuring low pressure.
2. After being subjected to pulse pressure for a long time, the spring tube is fatigued or there is leakage at the sealing parts at both ends. The two sealing parts can be repaired or re-tightened, and the spring tube will be scrapped if broken.
3. Long-term corroded by the measured medium, the spring tube will cause leakage. Corrosion-resistant pressure gauges should be selected, and spring tubes should be replaced if necessary.
4. Due to the quality of the spring tube, there are obvious cracks or ruptures. It is necessary to replace the high-quality spring tube of the same specification and take corresponding protective measures.
5. Improper selection of specifications, the measured pressure is close to the upper limit of the gauge, and the long-term pressure will cause fatigue and rupture. The pressure gauge of the appropriate specification should be carefully selected, and if the spring tube is broken, the tube of the same specification should be replaced.
1. The spring tube is deformed and fails, and the displacement is not proportional to the pressure. The spring tube needs to be replaced.
2. The transmission ratio between the free end of the spring tube, the sector gear and the wheel rod is not properly adjusted, and it needs to be checked and adjusted again.
3. The combination position of the gear splint and the bottom plate is wrong. The splint should be driven counterclockwise by loosening the joint screw.
4. The displacement of the pointer of the pressure gauge causes the tension of the hairspring to vary forward or backward. The tension of the hairspring can be adjusted to rotate the central gear.
During the pressurization process of the pressure gauge, the pointer of the pressure gauge jumps, becomes sluggish, and the variation is large. It means that there is friction in the transmission mechanism, and the instrument must be disassembled to check the meshing condition of the transmission mechanism and take necessary measures.
According to the characteristics of this error, we can draw the conclusion that the error of the pressure gauge to be inspected increases or decreases by an equal amount as the pressure increases. In the entire measurement range, the pointer reading is always different from the standard indication by a fixed value. This is a systematic error caused by the incorrect installation of the pointer. We do not need to worry about it because it is very easy to adjust this error.