Analytical Balance - Mettler

SOP FOR CLEANING, CALIBRATION AND OPERATION

1.0 OBJECTIVE
To lay down a procedure for cleaning, calibration & operation of the analytical balance (METTLER AR 104).

2.0 SCOPE
Module-4.

3.0 RESPONSIBILITY
Production officer.
QA chemist.

4.0 ACCOUNTABILITY
Production Executive.

5.0 PROCEDURE
5.1. Cleaning.
5.2. Calibration.
5.3. Operation.
5.4 Shut down.


5.1 Cleaning
5.1.1 Ensure that the power supply to the balance is switched ‘off’ before cleaning.
5.1.2 Clean the pan and inside of the balance with brush.
5.4.1 Clean the outside of the balance with clean and dry lint free duster every day.

5.2 Calibration
5.2.1 Frequency of calibration
5.2.2 Self Calibration Procedure

Frequency daily and after each maintenance job.
5.2.2.1 Clean the balance as per procedure given in 5.1
5.2.2.2 Check that air bubble is at the center of the level indicator and if required adjust the level by turning the leveling screws.
5.2.2.3 Switch on the balance and allow it to stabilize for 30 minutes.
5.2.2.4 Press the ‘cal’ button.The display should read ‘CAL’ followed by the blinking of 100.0000
5.2.2.5 Place 100.00g standard weight (METTLER).The display will blink 0.0000 g. Remove standard weight from balance.
5.2.2.6 After a few seconds the display should read ‘CAL DONE. This denotes end of self calibration.

5.2.3 Calibration against Standard weights
Frequency every month and after each maintenance job.
5.2.3.1 Clean the balance as per procedure given in 5.1
5.2.3.2 Check the weight of the standard weights 0.1000g, 0.2000g, 0.5000 g & 1.000 gms
5.2.3.3 Record the observations in calibration record.
5.2.3.4 If the variation is more than the least count label the balance ‘out of order’.
5.2.3.5 Error must be rectified and balance should be calibrated before use.

5.3. Operation
5.3.1 Ensure that balance is properly connected to the power supply.
5.3.2 Check that the air bubble of level indicator is at the center, and if required adjust the level by turning the leveling screws.
5.3.3 Switch on the main switch, this balance displays ‘88888888’ followed by 0.0000 g.
5.3.4 Place a clean petridish, close the balance door and press tare button on the bar to tare the petridish weight. The display should read
        0.0000g.
5.4.1 Place the required No. of tablets/capsules on petridish and close the balance door.
5.3.6 Wait until the stability symbol “O” displayed, then read of weight.

5.3 Shout down
5.4.1 Clean the balance as per procedure given in 5.1
5.4.2 Switch ‘off’ the balance.
5.4.3 Switch ‘off’ the mains