1. Install a 2-wire 4-20mA analog output pressure transmitter on the testing device

2. Connect the power lead to the positive terminal and the output lead to the negative terminal

3. Now pressurize the transmitter to 100% of the range and hold the pressure for a few seconds, then release the pressure.

4. The digital multimeter should display a zero pressure reading of 4mA and a full range value of 20mA. Check the low and high voltage values.

5. If any deviation is observed by rotating the potentiometer provided on the pressure transmitter, please perform zero and range adjustments. The KELLER pressure transmitter is calibrated using the endpoint method, and its accuracy includes zero position and span, repeatability, and hysteresis error. Therefore, our transmitter does not provide zero and span adjustment screws.

6. Record the readings of the upper and lower three points at 0%, 50%, and 100% of the pressure range. The 4-20mA output should be 4 mA, 12 mA, and 20 mA at three points. After reaching the testing point, let the tested equipment and measuring instruments stabilize before moving to the next point. According to application requirements, pressure transmitters can be calibrated at three or more points.

7. Compare the results with the reference main instrument to ensure that the error is within the limit range.