Level Transmitter SERVO Type SMP

Instrumentation Level
1

A change in liquid level varies the apparent weight of the displacer, which increases or decreases load on the torque tube by an amount directly proportional to the change in liquid level.

The resulting rotation of the torque rod modifies the magnetic field of a frictionless, non-contacting, Hall Effect sensor. The signal generated by the sensor varies current in the loop in proportion to the level in the vessel.

Calibration Procedure of SERVO Level Transmitter

  1. Remove process hazards by cleaning the transmitter.

  2. Make connections.

  3. Adjust input to 0%, 25%, 50%, 75% & 100% range value. Allow input pressure to stabilize for 10 seconds before taking further readings.

  4. Note down the transmitter output reading in calibration table, marked as ‘Before Adjustment’.

  5. If output is not within limits then to calibrate transmitter connect HHT to transmitter, irrespective of polarity.

  6. To access the calibration mode first select MATRIX PARAMETER mode by pressing  key , then in MATRIX PARAMETER MENU select CALIBRATION mode by pressing  key.

  7. To set or reset the 0% of range input, select SET 4 mA VALUE by pressing  key and press  key.

  8. Apply lower range value(LRV) pressure to the transmitter and, wait for 10 seconds to stabilize the pressure then enter this pressure by numeric keys and then press ENTER. Press  key to return Calibration menu & send data to transmitter.

  9. To set or reset the 100% of range input, select SET 20 mA VALUE by pressing  key and press  key.

  10. Apply upper range value (URV) pressure to the transmitter and, wait for 10 seconds to stabilize the pressure then enter this pressure by numeric keys and then press ENTER. Press  key to return Calibration menu & send data to transmitter.

  11. Disconnect HHT and put it OFF.

  12. Apply 0%, 25%, 50%, 75%, 100% pressure and measure ‘mA’. It should be 4mA, 8mA,12mA, 16mA, 20mA and note down the corresponding output of reading in calibration table, marked as ‘After Adjustment’.

  13. Affix a calibration sticker with date and signature on the transmitter.

  14. Enter transmitter tag no. and date of calibration in records.