CALIBRATION LABORATORY BALANCE / TOP LOADING DIGITAL BLANCES And TOP LOADING MECHANICAL SCALES

1. PURPOSE

1. To provide a procedure for maintenance and calibration of Laboratory balances, Top Loading digital balances and Top loading mechanical scales.

2. SCOPE

1. This procedure covers all scales and balance being calibrated.

3. EQUIPMENT USED

1. Dead Weights

4 PROCEDURE


Note down all relevant information of instrument in the Calibration Record Sheet.
Clean the balance.
djust zero error if applicable, check level of balance also and adjust it if required
The scales has to be checked on its complete span or working range.
Calibration should be done on at least four set points of complete span. The set points are normally taken as: 25% of FS, 50% of FS, 75% of FS and 100% of FS or any convenience reading.
Take calibrated weights equal to first set point and note down the reading in column marked SET VALUE data sheet.
Place the weight on scale and note down the reading of scale in the column marked
TRUE VALUE.
Repeat the step 6 and 7 for all other set points.
Now analyze the deviation. If the deviation. If the deviation is out of the specified deviation of the instrument it is to be adjusted until the deviation come within required deviation.
If the deviation is within specified deviation affix the calibration sticker on the instrument and submit the data sheet of Calibration incharge.
Calibration incharge prepares the calibration report and submit to the Manager maintenance.
The calibration report is sign by concern calibration incharge and then by Manager
Maintenance.