Operation and Calibration of Sartorius Analytical Balance

Operation and Calibration of Sartorius Analytical Balance

1.0 Objective
To lay down a Procedure for Operation and calibration of Sartorius Analytical Balance.
2.0 Scope
This Standard Operating Procedure is applicable for Operation and calibration of Sartorius Analytical Balance in Quality Control Department of abc company.
3.0 Responsibility
3.1 Officer/Executive QC or his designee shall be responsible to followed the SOP.
3.2 Head QC or his designee shall be responsible to ensure the activity as per SOP.
3.3 Head QA or his designee shall be responsible for implementation and compliance with SOP.
4.0 Abbreviations and Definitions
SOP : Standard Operating Procedure
QC : Quality Control
QA : Quality Assurance
5.0 Procedure
5.1 Operation procedure
5.1.1 Check and ensure that the instrument is clean and free from dust.
5.1.2 The level of the balance is properly adjusted by adjusting the bubble at the center.
5.1.3 Connect the balance to the power supply.
5.1.4 Press the ‘I/Q’ key to “ON/OFF” the balance. The balance will perform self test and “0.000 g” is displayed.
5.1.5 If the balance shows a small circle at the right top of the display it means the balance is in “OFF” mode.
5.1.6 If the balance shows a small circle at the left bottom of the display it means the balance is in “STAND BY” mode.
5.1.7 If the balance shows “0.000g” on the display it means balance is “STABLE”.
5.1.8 In order to take a weight, Open the side window and place the object or butter paper on which

the weight has to be taken on the pan. After the weight, unit “g” or other selected unit is displayed as the stability symbol.
5.1.9 Place the specimen on the object or butter paper (tare the weight of the object or butter paper)

and use the balance for weighing. In case the butter paper is used for weighing carefully transfer the

specimen to the respective container and again place the same butter paper on the pan.
5.1.10 Clean the pan and the platform of the balance using a brush after the weighing.
5.1.11 Make entry of balance usage in instrument log.
5.2 Handling of Weight Box
5.2.1 Store the weight box in dust free area.
5.2.2 Do not touch the weight with bare hand, for handling the weights use a forceps.
5.2.3 Use certified weights only.
5.2.4 For cleaning of weights use a lint free cloth moistened with small amount of Di-ethyl ether and air dry.
5.2.5 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 corner weighing differences.
5.3 General Instruction
5.3.1 Clean the pan and Platform of the balance after weighing is over.
5.3.2 Do not over load the balance of their maximum capacity.
5.3.3 Keep doors of the balance always closed.
5.3.4 Before closing and opening, ensure that the pan is empty.
5.3.5 Keep the balance in “STAND BY” position when not in use, by pressing I/Q’ key of the balance.
5.4 Cleaning
5.4.1 Before cleaning, disconnect the balance from the power supply.
5.4.2 Do not use any aggressive cleaning agents or strong solvents.
5.4.3 Use a piece of cloth which has been wet with a mild detergent (soap) to clean the weighing pan and balance housing.
5.4.4 Make sure that no liquid enters the balance housing.
5.4.5 After cleaning, wipe down the balance with a soft, dry piece of cloth.
5.4.6 Carefully remove any sample residue / spilled powder by using a brush that is placed with the balance.
5.5 Daily verification of Analytical Balance
5.5.1 Internal calibration (Self calibration/ Auto calibration)
5.5.1.1 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.
5.5.2 With Secondary standard weight
5.5.2.1 Calibrate the balance daily with the standard weights of 1g, 10g, 100 g & 200g individually. Record

the results as given in Annexure – 1.
5.5.2.2 Acceptance Criteria: ±0.1% of the Certified weight.
5.6 Monthly Calibration of Analytical Balance
5.6.1 Measurement of Uncertainty
5.6.1.1 Ensure that the standard weights used are within the validity period of its calibration.
5.6.1.2 The weights selected for uncertainty measurement are 1g, 5g & 10 g.
5.6.1.3 Measure the weights by keeping the standard weight at the positions (10 times, individually) as

given in the following diagram.

5.6.1.4 Calculate mean and standard deviation (S.D) for the weights taken above.
5.6.1.5 Calculate the uncertainty for all the selected weights by using following formula:

5.6.1.6 Acceptance criteria for uncertainty measurement: NMT 0.001.
5.6.1.7 Record the observations in annexure-2.
5.6.2 Calibration with Standard weights
5.6.2.1 Place 1 g certified weight in the centre of the pan. Close the door.
5.6.2.2 Wait until the weighing result is stable.
5.6.2.3 Now read the displayed weight.
5.6.2.4 Take out the 1 g weight and allow the balance to come to zero.
5.6.2.5 Repeat the above procedure for the certified weights of 2g, 5g, 10g, 20g, 50g, 100g and 200g.
5.6.2.6 Record the observations in annexure-2.
5.6.2.7 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