Weighing balance:
1.Objective
The objective of this SOP is to define the procedure for operating, calibrating, and cleaning different models of balances.
2. Scope
This procedure applies to balances used in the Microbiology Department.
3. Responsibilities
Microbiology Analyst Responsible for following the SOP.
Engineering personnel are responsible for preventive maintenance.
4. Accountability:
Head/designee of the Microbiology Department.
5. Procedure
Preliminary Check
Ensure the balance and surrounding areas are clean.
Check the calibration status and spirit level of the balance.
Make sure the balance’s weight limits are not exceeded.
Bring the material to room temperature before weighing if necessary.
Cleaning
Turn off the power supply before cleaning.
Use a lint-free cloth to clean the pan and surrounding areas.
Log cleaning activities in the usage logbook.
Operating Procedure for balance
Ensure cleanliness and level balance.
Wait for the balance to stabilize after turning it on.
Use various applications (e.g., weighing, mixing, statistics) for different tasks.
Sample Weighing
After calibration, ensure zero reading.
Tare the balance if needed and place the sample on the pan.
Stabilize the reading and record the weight.
If using containers or paper, tare the balance before weighing.
Printer Operation
Connect the printer to the balance and press the print button to generate reports with the necessary data (e.g., date, time, prepared by, reviewed by).
Calibration
Internal Calibration: Perform calibration using internal settings.
Daily Calibration: Check the balance with standard weights (e.g., 10g, 250g, 500g).
Monthly Calibration: Verify the balance’s accuracy, repeatability, and eccentricity using standard weights.
Acceptance Criteria: Ensure variations are within acceptable limits (e.g., ±0.05% of certified values).
Calibration Failure
If calibration fails, report the issue to the department head and notify the technical officer for maintenance.
6. Precautions
Clean the balance and surroundings after every use.
Avoid spilling substances, placing magnets, or putting excessive weight on the balance.
Keep the balance away from air currents and ensure the pan is not disturbed.
7. Abbreviations
SD: Standard Deviation
QA: Quality Assurance
MB: Microbiology
AD: Analytical Development
g: Gram
Kg: Kilogram
8. References
USP General Chapter 41 & 1251.
User Manuals for equipment.
This SOP ensures the proper operation and maintenance of balances used in the microbiological analysis, with clear steps for calibration, cleaning, and usage tracking.
8. References
Annexure-1: Useage Log of balance
Equipment Usage Log
Keeping track of equipment usage is essential for efficient operation and maintenance. Below is a sample format that can be used for recording equipment activity:
| Date | Activity | Start Time | End Time | Remarks | Operated By (Sign & Date) |
|---|---|---|---|---|---|
Reviewed By: (Sign & Date)