SOP For calibration of balance is described in this post which you can follow in the section of the General Industry SOP.

OBJECTIVE

To calibrate the equipment for reliable and accurate results.

SCOPE

This procedure is applicable for balance installed in the quality control department.

RESPONSIBILITY

QC Analyst

ACCOUNTABILITY

Manager Quality Control

PROCEDURE

  • Operate the instrument as per respective Standard Operating Procedure.
  • Switch ‘ON’ the instrument.
  • Switch ‘ON’ the balance.
  • After few seconds, the display will show 0.00 g.
  • If display is not stable, press the TARE key & wait till the display shows 0.00 g.
  • Perform internal calibration.

For Accuracy

  • Place 5 gm. on the weighing pan.
  • Note the weight.
  • Calculate the difference between the weight in certificate and observed weight.
  • Repeat the above steps using 50gm & 100 gm. weights.
  • Record the reading.

For precision

  • Place 5 gm. in the weighing pan.
  • Note the weight .
  • Repeat the above two steps nine times.
  • Record the weight.
  • Calculate the Standard deviation.

Calculate the measurement uncertainty using following equation.


                                                                                     2 X SD

                 Measurement uncertainty =    ------------------------------------

                                                                    Actual weight from certificate

Frequency

Internal calibration and accuracy: Daily

Precision: Once in a month