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Standard Operating Procedure for Operation and Calibration of Top Loading Balance used in the pharmaceutical industry, guideline, and formats of uses and calibration/qualification.

Operation & Calibration Procedure for Top Loading Balance

1.0   Purpose :

• • To lay down a procedure for Operation and Calibration of Top Loading Balance.

2.0   Scope : 

• • This SOP is applicable for Top Loading Balance used in pharmaceutical plants.

3.0   Responsibility : 

• • Officer, Executive — Shall be responsible for Operation and Calibration of Top Loading Balance used
    in the microbiology laboratory.

• • Head – QC/QA -Shall be responsible for compliance of SOP.

4.0   Procedure – Top Loading Balance

• • The operating range of balance is as follows: Maximum: 500g, Minimum: 10g

• •  The Maximum capacity of balance is 1200 g.

• • Print For print & Header in print out Function To select the function of the balance Tare For tare the weight

• • Preliminary Check of Top Loading Balance :

• • Ensure that the calibration status of the instrument, if the calibration date is due, do not use the instrument till the completion of calibration.

• • Ensure that the balance is placed in a vibration-free place.

• • Check the cleanliness,  Ensure that instrument is clean and free from dust, if not then clean the pan with a camel hair brush or its equivalent.

• • Switch ON the mains; ensure that the spirit level of the balance is at the center (bubble position in the center).

• • Level the balance, to do it turns the feet in a way indicated by bubble position on the display, the level point moves towards the center of the level circle.

• • Top Loading Balance Instrument Operation Procedure :

• • Connect the balance and printer to the power supply.

• • The balance must warm-up for at least 15 minutes after initial connection to AC Power.

• • Switch on the balance with the help of the “ON/OFF” key given on the front panel.

• • Ensure that the printer is connected to the balance.

• Procedure for weighing samples on Top Loading Balance :

• • Before weighing on the balance ensure the spirit level (bubble position) in the center.

• • Before weighing the sample keep the balance on Statistics mode. (Select the statistics mode in primer by pressing MODE key in Printer)

• • Balance shows a constant 0.00 g on the display, which means that the balance is stable.

• • Place the container or the butter paper on the balance in the center of the pan.

• • Press the Tare key to tare the weight of the container or butter paper.

• • Add sample to the container or on the butter paper. The display shows the sample weight. Press Print key, then Header comes with weight.

• • Press MODE Key on the printer to get statistical data with the footer.

• • After weighing is over bring the display to 0.00 by pressing the Tare key.

• • Clean the pan and the platform of the balance after the weighing is over.

• • Fill the Sample name on weight print and put signature and date.

• Calibration Procedure of Top Loading Balance :

• • Daily  – Daily verification

• • Monthly – Repeatability, Accuracy, Entire Wei9ht Range Check Test, Sensitivity, Linearity, Eccentricity

• • Ensure that the standard weights Used are within the validity period of its calibration.

• • Calibration shall be done within the acceptance criteria of frequency defined in the respective SOP for Internal Calibration.

• • Daily Verification of Top Loading Balance :

  • Daily verification shall be performed daily before the start of the analysis.

• • Balance Level:

• • Check the balance spirit level. (If the level is disturbed, correct it by adjusting the base screws). Record it in Annexure.

• • If the balance spirit level is not visible properly, check the spirit level of the Top Loading balance by using an external spirit level device.

• • Zero Display:

• • After Stabilizing of Top Loading balance the display will be shown at 0.00 g constantly. Record the zero display in the annexure.

• • Weight Verification (Using Weight Box):

• • Press the TARE key to zero the display if necessary.

• • Place the check weight (10g) on the weighing pan with the help of forceps of the balance and allow it to stabilize. Print the displayed weight and enter in Annexure.

• • Repeat the operation with weight 50.0 g, 100.0 g, and 500.0 g on the weighing pan of the balance and allow it to stabilize.

• • Record the same in Annexure.

• •  Acceptance criteria:

• • The difference in the observed and actual values shall not be more than 0.1% from the actual value
    or  ± 0.1% of actual weight (refer to the calibration certificate of the weight box).

• • Monthly Calibration of Top Loading Balance :

• • Top Loading Balance time shall be verified before monthly calibration and as and when required with server time. In case of any variance i.e. ± 2 minutes from GPS clock. synchronization of the clock has to be done manually with GPS time with the help of the IT Department. Request for the same shall be initiated and verified by QC personnel.

• • Before monthly calibration Balance level, zero display, and Balance Time Verification shall be done and recorded in format.

• • Repeatability Check of Balance :

• • Weigh the selected test weight i.e. 200g weight, 10 times and take the printout of all the weighing.

• • Before taking the print for each weighing ensure that the Top Loading balance displays a constant value.

• • Calculate the Repeatability by using the following formula :

                                                   2 x S.D.
Repeatability = -—–——-—-—————–—–— x 100
Desired smallest net weight

Note: In the above case if the Standard Deviation obtained is less than (0.41d) then consider standard deviation as (0.41d), where d = Readability of the balance.

Where
S.D.: Standard Deviation as mentioned in the weight print. Desired smallest net weight: 10 g.

• • Acceptance Criteria:  ≤0.10 %.

• • Accuracy Test of Balance :

• • Tare the balance by pressing the Tare Button key. Place the weight and after getting a constant reading press the print button key on the Top Loading balance to start the weighing (Header Print).

• • Place the test weight at the center of the pan and take the print of the respective weights, Carry out the test with five test weights i.e. 20g, 50g, 100g, 200g, and 500g. After completion press the “Mode Button on printer” key to get statistical data. Record the values. Record the value in Annexure.

• • Acceptance Criteria:  ±0.10% of the actual weight (Certificate Weight).

• • Sensitivity Test – Balance Calibration:

• • Carry out the test with a single test weight i.e. 500 g.

• • Place 500g weight on the pan, by using Print key print the weight. After completion press the “Mode ok button” key to get statistical data.

• • Record the value in Annexure.

• • Set the Calculate the % deviation for the sensitivity test by using below mentioned formula:

Change in weighing in g

Sensitivity = ———-—-—-——– —— 100
Change in load in g

Weight

Change in weighing in g = Initial reading – Display weight

Change in load in g – Initial reading – Actual Standard (Certificate)

% Deviation = [ Sensitivity -100]

• • Acceptance Criteria:  Sensitivity should be not more than 0.05%.

• • Entire Weighing Range Check Test:

  • This test is performed to check the balance performance for its entire weight range.
    (10g, 20g, 50g, 100g, 200g, and 5009.)

• • Press the Zero key on the balance to start the Balance/weighing. Tare the balance from the Tare menu, Wait till 0.00g is displayed. Weigh the entire test weight range i.e. 10 g,20 g, 50 g, 100 g, 200 g, and 500 g by keeping the weights on the pan and pressing the print button key, print the weight. Select the “Mode OK” (on printer) key to get statistical data.

• • Before taking the print for each weighing ensure that the Top Loading balance shows a constant value.

• • Pressing the “Mode Ok” button on the printer also prim the end time and signature. Record the value in Annexure.

• • Calculate the % Deviation using the below-mentioned formula:

Display weight X 100

% Deviation = —————————————————-     – 100

                                                                ActualStandard (Certificate) Weight

• • Acceptance Criteria: ± 0.10% of the actual weight (Certificate Weight).

• • Linearity of Balance :

• • Tare the balance, place 50g test weight on the pan, allow the reading to get stabilized, and press the “print” key for printout.

• • Remove 50 g test weight and put 50g load (20g+20g+10g), tare the balance. Now again place the 50g (Test weight) allow the reading to get stabilized and press the “print” key for printout.

• • Remove 50g+20g+20g+1Og test weight and put 100g load, tare the Top Loading balance. Now again place the 50g (Test weight). Allow the reading to get stabilized and press the “print” key for printout.

• • Now remove 100g+50g test weight and put 100g+20g+20g+10g load, tare the balance. Now again
    place the 50g (Test weight), allow the reading to get stabilized, and press the “print” key for printout.

• • After completion press “Mode ok on printer” to get statistical data and footer and record the values in Annexure.

• • Determine the % Linearity by using the below-mentioned formula :

Linearity = (Maximum weight — Minimum Weight) / 2

Maximum Weight and Minimum Weight: As mentioned in the weight print

% Linearity =(Linearity x 100 ) / Test Weight         

Where test weight is the actual weight.

• • Acceptance Criteria: Deviation should be ≤ 0.05%.

• • Eccentricity (Off Center Load):

• • Press the Zero key on the Top Loading balance to start the weighing. Tare the balance by pressing the Tare menu key & carry out the test using the 200g test weight. Place the test weight on the center (C) of the pan, allow the weight to get a constant value, and then press function mode followed by print units” key for printout.

• • Repeat the above procedure by keeping the test weight on different positions as shown below (Four different places i.e., C1, C2, C3, and C4 respectively) and check the deviation from the center. Press the “Mode ok key” on the printer key to get statistical data and the footer.

• • Calculate the % Deviation from the center ‘C’ as

                                Difference between displayed Weight of position ‘X’ and displayed Weight of center (g)
% Deviation from center = -——————————————————–————-——-—–———–———- X 100
Displayed weight at position ‘X’

Where ‘X’ = C1, C2, C3, and C4 position.

For e.g. (C1-C) x100 , (C2-C) x100 , (C3-C\x100 . C4C) x100 C1 C2 C3 C4

• • Acceptance Criteria: Deviation should be ≥ 0.05%.

• • If failure to meet the calibration acceptance criteria, the “OUT OF CALIBRATION” label shall be placed on the instrument and proceed as per out of calibration SOP.

• Cleaning Procedure of Balance :

• • Before cleaning, Switch off the Top Loading balance and remove the pan.

• • Ensure that all power connections of the instruments are removed.

• • Before and after every test clean the sample pan and other accessories using a camel’s hairbrush or its equivalent.

• • Carefully remove any sample residue / spilled powder using the brush.

• • Clean the pan with tissue, which has been wet with 70% IPA.

• • Clean the inner parts with a soft brush.

• • For cleaning of weighing pan, remove it and then clean it.

• • After cleaning, wipe down the balance with a soft, dry piece of cloth.

• Procedure to shut down the Top Loading Balance:

• • Press the Zero key on the keypad for OFF of balance.

• • Switch off the mains.

• Precaution during handling of Balance (Good Weighing Practices)

• • Avoid mechanical shock, vibration, and air current to the weighing balance.

• • Keep magnetic substances away from the balance.

• • Do not spill solid samples or liquids on the balance pan and inside the balance.

• • Clean the balance pan and its surrounding immediately, if the sample is spilled.

• • Do not place a weight beyond the range of the balance on the weighing pan.

• • Shorten the operation time as much as possible to avoid errors caused by environmental conditions.

• • Make sure that the containers used to receive the weighed material are clean and dry.

• • Do not use organic solvents to clean the balance.

• • Use forceps to carry weight during calibration.

• • Maintenance of the Instrument:

• • In case of malfunction of the instrument, inform the section head or GLP person for corrective action to be implemented.

• • Calibration of Top loading balance is to be done by an outside agency once a year.

Annexure I: Daily Balance Calibration/ Verification

Daily Calibration Record of Top Loading Balance

Frequency : Daily                                                                Month/Year : ____________

Daily Verification Using weight box :

i) Weight Box ID____________ ii) Certificate No. ___________ iii) Valid up to __________

Note : * Record the balance level (Bubble position in the center), Zero Display,& internal calibration as OK/Not OK.

Annexure-II: Monthly Balance Calibration

Monthly Calibration Record of Top Loading Balance

• Balance Time Synchronization :

• Balance Level & Zero Display :

Note:  Record the balance level (Bubble position in the center), Zero Display,& internal calibration as OK/Not OK.

Monthly Balance Calibration

1.0   Repeatability

Check Weight (200.0g)

1. Weight Box ID: –
2. Certificate No. : –
3. Valid up to:-

 Calculation:   Repeatability = (2*S.D)/Desired Smallest Net Weight

Acceptance Criteria: ≤ 0.10%

2.0   Accuracy

1. Weight Box ID: –
2. Certificate No. : –
3. Valid up to:-

Acceptance Criteria: ± 0.10% of actual weight

3.0   Sensitivity

1. Weight Box ID : –
2. Certificate No. : –
3. Valid up to :-

Check Weight (500.0 g)

Sensitivity = (change in Weighing/Change in Load)*100

Where

Change in weighing is (Tare – Observed weight)

Change in Load is (Tare weight – Actual Weight)

% Deviation =             Sensitivity – 100

Acceptance Criteria: Sensitivity does not deviate ≤ 0.05%.

4.0   Entire Weight Range

1. Weight Box ID: –
2. Certificate No. : –
3. Valid up to:-

Acceptance Criteria: ± 0.10% of actual weight

5.0   Linearity

Linearity   = (Maximum weight – Minimum Weight) / 2

% Linearity   =(Linearity x 100) / Test Weight

Acceptance Criteria: Should not deviate ≤ 0.05%.

6.0   Eccentricity (off Center Load)

1. Weight Box ID: –
2. Certificate No. : –
3. Valid up to:-

Weights are to be placed at 4 different positions.

% Deviation   = (Deviation from Center) x 100 / Displayed  Weight

Acceptance Criteria : Deviation should be ≤ 0.05% .

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