SOP for Operation and Calibration of Moisture Analyzer

To lay down a procedure for the Operation and Calibration of the Moisture analyzer.

This procedure applies to the production department in the Pharmaceutical Manufacturing Facilities of XYZ Limited.

The concerned staff is responsible for the implementation of the process.
The Production In-Charge is responsible for the execution and compliance of the procedure.


  • Ensure that the power supply to be moisture balanced is switched off before cleaning.
  • Lift the body & clean the inside of the moisture balance with a brush.
  • Clean the outside of the moisture balance with a clean & dry lint-free duster every day.

  • Frequency of calibration: monthly & after each maintenance job.
  • Self-calibration procedure:
  1. Clean the balance as per the procedure given above.
  2. Check that the air bubble is at the center of the level indicator & if required adjust the level by turning the leveling screws.
  3. Place aluminum dish on.
  4. Switch on the moisture balance and allow it to stabilize for 30 minutes.
  5. Press the ‘Ca‘ button.
  6. After a few seconds, the display should read 100.000 gm., then place a std. 100.000 gm. Wt. on an aluminum dish, then it denotes 0.000 gm. that denotes the end of self-calibration.
  7. In case of display ‘error,’ tare & press cal repeat the procedure to ensure 0.000 gm.
  • Calibration against standards weights:
  1. Clean the balance as per the procedure given above.
  2. Check the weight of the standard weights. (1.000 gm., 0.500 gm., 0.200 gm. and 0.100 gm.).
  3. Records the observations in the calibration record.
  4. If the variation is more than the least count label the balance ‘out of order’.
  5. An error must be rectified and the balance should be calibrated before use.

  • Ensure that the moisture balance is properly connected to the power supply.
  • Check that the air bubble of the level indicator is at the center, and if required adjust the level by turning the leveling screws.
  • Switch on the main switches, and then the moisture balance displays 0.000 gm.
  • Place a clean aluminum dish and press the tare button on the bar to take the aluminum dish weight. This display should record 0.000 gm.
  • Place approx. 2.000 gm. of powder on an aluminum dish and close the main body.
  • Set the temperature by pressing the temperature key.
  • Then press the START button.
  • Wait till % of the moisture is displayed on the balance.

Shut down
  • Clean the moisture balance as per the procedure given above.
  • Switch off the balance.
  • Switch off the mains.
  • All the calibration details shall be entered in the calibration record.


Q.A : Quality Assurance
SOP : Standard Operating Procedure
No. : Number
P.D : Production
gm : Grams
Cal : Calibration

Annexure 1 - Calibration record for moisture analyzer


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