The pressure gauge needs to be verified in many aspects before installation and use. After the verification result is qualified, it can be formally put into use. When verifying the indication error of the pressure gauge, the calibration test bench with higher precision can be used as the standard table for auxiliary verification.

1. Verification of indication error

The pressure indication value test is carried out successively (boost or buck) according to the numbered index line. In the verification process, the pressure is increased evenly and slowly from zero to the standard meter pointer to the corresponding index line, and the detected value is read. Then tap the gauge housing, and then read, record the value after tapping and the tap displacement (the difference between the value before and after tapping). When the indicated value reaches the upper limit of the measurement, close the pressure supply valve of the tester, cut off the pressure source (or vacuum source), withstand the pressure for 3 minutes, and then perform step-down verification successively until zero. The return error and tapping displacement should meet the requirements specified in the verification regulations.

If the gauge is a pressure and vacuum gauge, the vacuum part is verified, if the gauge is a special pressure gauge, additional verification should be carried out for different situations. However, it is necessary to implement the verification regulations and record the relevant situation.

Two, indicating the value of the error reading

According to the requirements of the regulations, the value of the pressure gauge should be evaluated according to 1/5 of the index value, the standard table uses the line reading, and the meter to be inspected uses the estimated reading. As for the comparison of the two reading methods, the accuracy of the line reading is higher than that of the estimated reading. The end width of the standard meter pointer, the scribbling interval and the mirror background on the dial are more conducive to accurate estimation of the reading than the meter being checked, and can usually be estimated to 1/10 of the index value. All the verification results are filled in the original records, and the verification data are calculated and processed to ensure that the data is accurate and reliable.

Iii. Processing of verification results

The certified pressure gauge shall be removed from the calibrator, stamped with the lead seal of the metrological verification institution, affixed with the metrological qualification label, and finally issued a metrological verification certificate. To verify the unqualified pressure gauge, the unqualified items should be repeatedly adjusted, repaired and verified, and the above verification procedures should be re-implemented after adjustment and repair; If the damage is serious and can not be repaired, the notification of verification results shall be issued, and the unqualified items and contents shall be indicated.

The above are the three steps to verify the indicating error of the pressure gauge with the calibration test bench. To master the verification process of the error of the pressure indication value and the operation method of the calibration test bench is helpful to obtain accurate and effective verification results and ensure the product quality of the pressure gauge.