We can see its detailed information on the transmitter’s nameplate: such as its operating voltage, accuracy level, and its range, etc.
The pressure transmitter can convert the pressure value of the measured medium into a current value of 4~20 mA for output. 4 mA represents the 0 bit and 20 mA represents the full scale. The content of our verification is to observe whether the pressure value of the transmitter at the corresponding milliampere value is correct. Let’s start the calibration of the pressure transmitter!
Calibration of pressure transmitter
Tool
The tools we need to prepare are: intelligent analyzer, calibration bench, pressure transmitter, identification table and test pen.
Check appearance
First check the appearance to make sure it is intact and not damaged.
Install calibration equipment
Before installation, confirm that the calibration bench is not pressurized. Open the analyzer, tighten the pressure relief valve, energize the transmitter, and perform calibration after 10 minutes.
Calibration
Measure the pressure value of the pressure transmitter at 4 mA, 8 mA, 12 mA, 16 mA and 20 mA output signals. And record the value on the identification form.
After recording the output value of the upper stroke, continue to record the output value of the lower stroke, repeat three times to reduce the error as much as possible.
When calibration of zero and full positions is required during the calibration process, we can open the nameplate of the transmission. There are adjustment holes for zero and full positions under it, which can be adjusted by inserting them.
After the calibration is completed, first remove the pressure from the calibrator. Then open the pressure relief valve. It is strictly forbidden to open the valve under pressure, disassemble the transmission, and restore the instrument.
Calculate whether the actual error of the pressure transmission is within the allowable error range by using the data recorded on the identification table. Pressure transmissions that fail to pass the calibration need to be calibrated in depth. Only pressure transmitters that pass the calibration will be affixed with a certificate of conformity and the calibration date will be recorded.
This verification is over.