Pressure Differential Switch Calibration
Test Equipment Required:
- Pneumatic Calibration
- Digital Multimeter
- Test Gauge
Typical Test Set-up
a. Check and confirm instrument range as per specification.
b. Hook-up instrument as per typical test set-up.
For Switch Low
1) Apply the calibrating pressure above the reset value of the set pressure.
2) Slowly decrease the calibrating pressure and confirm switch contacts transfer from N.C. to N.O. (or vice versa).
3) Record the pressure where the switch contact transfer happened.
4) Increase the calibrating pressure until the switch resets (Multimeter continuity will change) and record the reset point.
For Switch High
1) Gradually increase the calibrating pressure to the set pressure and confirm switch contact transfers from NC to NO (or vice versa).
2) Record the pressure where the switch contact transfer.
3) Decrease the calibrating pressure until the switch resets (Multimeter continuity will change) and record the set point
Record all result in instrument Calibration (Switches) Test Check sheets or Calibration Check Sheet.