Calibration & Verification Of Analytical Balance

1.0 Objective
To lay down a guidelines for Calibration & Verification of Analytical Balance in Quality Control Department.
2.0 Scope
This SOP applies to Calibration of Analytical Balance used in Quality control Lab in abc company
3.0 Responsibility
3.1 Executive – Quality Control.
3.2 In charge/Head.
4.0 Abbreviations and Definitions
SOP : Standard Operating Procedure
QC : Quality Control
CC NO : Change Control Number
cGMP : Current Good Manufacturing Practice
C : Calibration
SD : Standard deviation
gm. : Gram
5.0 Procedure
5.1 Handling of Weight Box
5.1.1 Store the weight box in dust free area.
5.1.2 Do not touch the weight with bare hand, for handing the weight use a forceps.
5.1.3 Use certified weights only.
5.1.4 For cleaning of weights use a lint free cloth moistened with small amount of Di-ethyl ether and air dry.
5.1.5 Do not drop the weight on the pan to avoid any damage to the balance. Gently place the weight on the center

of the pan to eliminate comer weighing differences.
5.2 General Instruction
5.2.1 Clean the pan and Plat form of the balance after weighing is over.
5.2.2 Do not over load the balance of their maximum capacity.
5.2.3 Keep doors of the balance always closed.
5.2.4 Before closing and opening, ensure that the pan is empty.
5.2.5 Keep the balance in “STAND BY” position when not in use, by pressing I/Q’ key of the balance.
5.3 Cleaning
5.3.1 Before cleaning, disconnect the balance from the power supply.
5.3.2 Do not use any aggressive cleaning agents or strong solvents.
5.3.3 Use a piece of cloth which has been wet with a mild detergent (soap) to clean the weighing pan and balance housing.
5.3.4 Make sure that no liquid enters the balance housing.
5.3.5 After cleaning, wipe down the balance with a soft, dry piece of cloth.
5.3.6 Carefully remove any sample residue/ spilled powder by using a brush that is placed with the balance.
5.4 Daily verification of Analytical Balance
5.4.1 Internal calibration (Self-calibration/ Auto calibration)
5.4.1.1 Press “CAL” key. Balance will go into automatic self calibration mode and “CAL” will be displayed,

the “CC” will be displayed after self calibration is over display will show 0.000 g, then balance is

ready for use. Record the observation in the given Annexure-1.
5.4.2 With Secondary standard weight
5.4.2.1 Calibration the balance daily with the standard weights of 1 g, 10g, 100 g & 200 g individually. Record

the results as given in Annexure-1.
5.4.2.2 Acceptance Criteria: ±0.1% of the Certified weight.
5.5 Monthly Calibration od Analytical Balance
5.5.1 Measurement of Uncertainty
5.5.1.1 Ensure that the standard weights used are within the validity period of its calibration.
5.5.1.2 The weights selected for uncertainty measurement are 1 g, 5 g & 10 g.
5.5.1.3 Measure the weights by keeping the standard weight at the positions (10 times, individually)

as given in the following diagram.

5.5.1.6 Acceptance criteria for uncertainty measurement: NMT-0.001
5.5.1.7 Record the observations in annexure-2.
5.5.2 Calibration with standard weights
5.5.2.1 Place 1 g certified weight in the center of the pan. Close the door.
5.5.2.2 Wait until the weighing result is stable.
5.5.2.3 Now read the displayed weight.
5.5.2.4 Take out the 1 g weight and allow the balance to come to zero.
5.5.2.5 Repeat the above procedure for the certified weights of 2g, 5g, 10g, 20g, 50g, 100g and 200g.
5.5.2.6 Record the observations in annexure-2.
5.5.2.7 Acceptance Criteria: ±0.1% of the certified weight.
6.0 Forms and Records
6.1 Daily verification record of Analytical Balance – Annexure-1
6.2 Monthly calibration of Analytical Balance – Annexure-2
7.0 Distribution
7.1 Master copy – Documentation Cell (Quality Assurance)
7.2 Control copy – Quality Control
8.0 History