Posted 01 Dec 2010 11:10
When we test gauge gas regulator, usually to remove the pressure gauge on the gas pressure reducer, water as a pressure transmission medium, were seized by the comparison table to complete the standard test device, and then reinstall it. However, this test method has been unsatisfactory. Its problem is: when disassembly regulator gauge the possibility of leakage; was seized gauge easy to pollution (oil as a pressure transmission medium, were seized on the table and the standard features of the internal structure of the table does not cause it to clean the net); the direction of the gas regulator on the pressure gauge is not easy to observe the change in readings. In response to these problems, we developed a gas pressure reducer calibration device. Reference JJG52-1999 "Spring Tube general pressure gauges, pressure vacuum gauge and vacuum meter" test procedures and JJG913-1996 "buoy type oxygen inhaler" verification procedures, we use a gas regulator gas regulator on the overall calibration device calibrated. To calibrate the oxygen regulator is the main technical indicators of the table, for example, the calibration method proposed to discuss with you. First, the calibration device and associated equipment with the standard range of 0.1 to 25MPa and 4MPa each a Class A digital pressure gauge; gas pressure reducer calibration device; internal pressure nitrogen bottles in more than 9MPa; security guard. Second, the calibration and calibration verification device and method for oxygen gas regulator pressure reducer connected to the installation table 1. Stress that error, return error and tapping the gas pressure reducer displacement calibration gas regulator installed in the school inspection device, the indication of oxygen calibration table marked with numbers by dividing lines. Gradual smooth calibration step, when the indication to measure the cap, cut off the pressure source, pressure 3 minutes, then smooth the original calibration point buck reverse back to the examination. Pressure gauge indication scale value should be 1 / 5 of estimated time. (1) shows the error in the calibration points for each calibration step and the step-down, tapping the former case, the standard indication after the device shows the difference between the value should be less than that required to be calibrated instrument absolute tolerance. (2) return the same error in the calibration points on the ascending and descending pressure calibration, said after tapping case should not exceed the difference between the value of the instrument was calibrated absolute value of the allowable error. (3) tapping the shift in the calibration points for each calibration step and the step-down, tap the case said after the value changes caused by the amount should be less than the instrument is calibrated the absolute value of the allowable error of 1 / 2 . 2. Gas pressure reducer seal inspection (1) within the high and low gas pressure reducer of the main chamber pressure reducer and gas tightness check calibration device when connected to high voltage side of the oxygen regulator to the cylinder using the rated pressure (such as oxygen pressure reducer 15MPa calibration point), the oxygen regulator low pressure side connected with the calibration device. Pressure 1 minute, observe the low end of the standard meter readings, you can detect the seal within the gas regulator. This check can be high-pressure side pressure gauge in the gas regulator travel the calibration process is carried out. (2) Check the tightness of the gas pressure reducer external calibration device when the gas pressure reducer connected to the oxygen regulator of high end and low end to the use of the rated pressure cylinders, pressure 1 minute, observe the high-pressure standard table-side and low side readings, the standard form when the pressure drops rapidly, indicating that the external oxygen pressure reducer has leaks, you can use leak detection fluid leaking part. Third, the conclusion can be achieved using the calibration method to calibrate the gas regulator does not remove the pressure gauge. Since the use of nitrogen as the medium, so check the main parts of gas regulator will not cause corrosion within the main body. Calibrated by this method can not only form the oxygen pressure reducer, add or replace the appropriate standard device, you can calibrate the nitrogen (N2), argon (Ar), helium (He), hydrogen (H2), carbon dioxide (CO2) such as gas pressure reducer. Pressure gauge on the gas pressure reducer has rated pressure, calibration is not required to calibrate the instrument limit. Finally, I propose the organization as soon as possible to develop standardized calibration gas regulator. Because oxygen and other pressure instruments table in the industrial, scientific and other heavy use areas, the implementation of the scientific method not only with the calibration conditions, and is a priority.