Procedure for Operation and Calibration of Top Load Balance

1.0 Purpose   :      

            To lay down the Procedure for Operation and Calibration of Top Load Balance.

2.0       Scope   :

This procedure is to be followed during operation and calibration of Top Load Balance with the following details.           

3.0       Responsibility:

3.1       The responsibility of operation and calibration of top load balance lies with Microbiologist.

4.0       Definitions/Abbreviations     : Nil

5.0       Procedure      :

5.1       Operating Procedure for Top Load Balance:

5.1.1    The balance shall be leveled by rotating the level screws at the rear of the balance housing until the air bubble is in the center of the level indicator if required.

5.1.2    Switch ON the main switch.

5.1.3Press “ON/OFF” key.

5.1.4Wait for about 30 seconds for the initialization of the balance. After initialization the balance displays ‘0.00’ g.

5.1.5When ‘0.00’ g is displayed, the balance is ready for operation.

5.1.6Place the empty container / butter paper on the center of the pan.

5.1.7Wait till the balance shows stable reading.

5.1.8Tare the weight by pressing ‘TARE’ key briefly. The display changes to ‘0.00’ g Now the weight of the container / paper is tarred.

5.1.9Add weighing sample to the container / paper till the required weight is displayed.

5.1.10Wait until the balance shows stable reading.

5.1.11Transfer the sample carefully into the flask and place the butter paper or weighing object on the pan carefully.

5.1.12Wait till the balance shows stable reading.

5.1.13Absolute value of the negative reading displayed is the actual weight of the sample.

5.1.14Note down the transferred weight.

5.1.15Press and hold the mode off until “OFF” appears in the display and release the key.

5.2       Precautions    :

5.2.1    The balance should be free from vibration, air thrust, strong heat and moisture.

5.2.2    Do not weigh beyond the weighing range (300.0g).

5.3       Calibration     :

5.3.1    Daily Calibration:

5.3.1.1 With the balance turned ON, press and hold ‘MODE’ key until “CAL” is displayed.

5.3.1.2 Press the ‘TARE” key.

5.3.1.3 The value of the weight to be used for calibration flashes on the display (300.00 g).

5.3.1.4 Place the indicated span calibration mass of 300g on the pan.

5.3.1.5 Press ‘TARE’ key, when the balance shows stable reading.

5.3.1.6Zero shall be displayed (0.00 g).

5.3.1.7Remove the calibration mass from the pan and press the ‘TARE’ key, when the balance shows stable reading.

5.3.1.8“End” shall be appeared on the display and returns to the weighing mode.

5.3.1.9Place the calibrated weight of 1g, 50g and 200g on the pan of the balance and record the observed weight in the calibration record of top load balance.

5.3.2Quarterly calibration with a multiple standard weights:

5.3.2.1Check the calibration of the balance by using standard weights.

5.3.2.2Place 1g, , 5g, 10g, 50g, 100g and 200g weights on the pan and record the observed weight in the calibration record of top load balance.

5.3.3Acceptance Criteria:

Quarterly calibration shall be performed once in 3 months ± 7 days     

6.0       Related Documents:  Nil

Microbiology, calibration, standard weights