WhenPressure transmitterWhen coordinating with the secondary instrument for calibration, the resistance of the connecting wires should be adjusted according to the requirements of the secondary instrument (the resistance required for the dynamic coil indicator is 5 ohms), and the internal resistance of the signal source (the output internal resistance of the pressure transmitter) should also be checked to see if it is 120 ± 20% ohms.
The verification steps are:
1. Install the standard pressure gauge and pressure transmitter onto the pressure calibrator, and connect the connecting wires according to the specified values.
2. Adjust the mechanical zero point of the secondary instrument when there is no pressure applied. After connecting the power supply, adjust the DC voltage supplied by the stabilized power supply to the Zier chip to 3 volts.
3. Slowly increase the pressure, select four or more calibration points for calibration, and record the readings.
4. After the pointer reaches the upper * and the pressure stops for 5 minutes, perform a pressure reduction reverse stroke verification.
During the verification process, if the reading of the secondary instrument is above or below the standard value, the amplitude modulation potentiometer can be adjusted to change the magnitude of the voltage supplied to the Hall sensor.