1. Zero Adjustment Procedure

1.1 Side Mounting Type

1. Close the isolating valve completely.

2. Open the drain & test plug fully to release trapped liquid.

3. Wait for at least 3-5 minutes before proceeding.

1.2 Submersible Type

1. Remove the pressure transmitter or ensure the tank is empty.

2. Inspect the cable for any defects.

3. Measure the loop current using a multimeter. The output current should read 4.00mA when the tank is empty.

4. If the reading deviates from 4.00mA (±0.02mA):

   • Adjust the zero potentiometer on the PCB using a minus (-) screwdriver.

   • Do not touch the span potentiometer.

5. If a KFDO type barrier is installed, adjust the zero potentiometer to 3.80mA to compensate for current consumption.

2. Span Adjustment Procedure

2.1 Calibration Setup

• Submersible Type:

  1. Connect a pressure calibrator to the calibration adapter using a 1/8" connector and urethane tube after completing the zero adjustment.

• Side Mounting Type:

  1. Verify that the I.S. valve for the relevant tank is closed after completing the zero setting.

  2. Loosen the test plug and connect it to a 1/8" connector.

  3. Attach the pressure calibrator to the 1/8" connector using a urethane tube.

2.2 Span Adjustment

1. If the pressure transmitter’s range is 0-20 mH2O:

   • Apply 20.00 mH2O pressure using the calibrator.

   • Adjust the span potentiometer on the amplifier PCB to read 20.00mA on the ammeter.

3. Final Validation

1. Comparing Actual Level with C.R.T Display

• After setting zero, compare:
  • Actual tank level (volume)
  • C.R.T level (volume)
  • Current output from PCB
• If there is a large difference, voltage values should be checked.
• 

2. Voltage Measurement (With & Without Sensor)

• Measure the voltage between sensor wires in both connected and disconnected conditions.
• Record the Brown-Blue, Blue-Red, and Brown-Red voltage values for analysis.
• 
• 

3. Resistance Check for Sensor Cable

• • Using a multi-meter, measure and record resistance values for:
    • Brown-Red
    • Brown-Blue
    • Blue-Red
    • Brown-Earth
    • Red-Earth
    • Blue-Earth
  • These resistance values help diagnose faulty transducers or amplifiers.
  • 
  • 

4. Troubleshooting Guidelines

1. Zero Adjustment Issues:

   • If zero output does not stabilize at 4.00mA, check the wiring and connections.

   • Ensure there is no residual pressure in the system before calibration.

2. Span Adjustment Errors:

   • If the span reading is inaccurate, verify that the calibrator is applying the correct pressure.

   • Ensure the span potentiometer is adjusted precisely to 20.00mA.

3. Signal Fluctuations:

   • Inspect the cable and grounding connections for potential faults.

   • Confirm the power supply voltage is stable within the specified range.

   •