SOPs of Analytical Balance
SCOPE:
It SOPs covers the procedure for the operation of Analytical balance.
RESPONSIBILITY:
Chemist-QC
ACCOUNTABILITY:
Manager-QC
DEFINITION:
It is a balance that shows the weight of a substance digitally and is used to weigh chemicals in labs.
PROCEDURE:
- Make sure that the balance is kept clean.
- Ensure that the calibration status is valid.
- Ensure that spirit level is in the center of the circle.
- Connect the power cable to the mains and switch ‘ON’.
- Warm up the balance.
- Apply power in advance for one hour or more. This will allow you to immediately make an accurate measurement.
- Even if the balance is not used, keep the standby mark lit (warm-up state) by pressing the POWER/BRK key without disconnecting the AC adapter. ► If the balance is not used for one month or more, disconnect the AC adapter.
- Preparation for weighing making a measurement mode > Press the POWER/BRK key. The standby mark goes off and all displays light. Check that there is no segment that is not lit. ► The balance shows zero and enters the measurement mode.
Measurement
- When using a tare, load the tare on the pan and press the TARE key after a stability mark is lit. ► Check that the display shows zero.
- Load a sample. When the stability mark is lit, read the display. If the total mass of the sample and tare exceeds the weighing capacity, “OL” will be displayed.
- X Tare: A sample container or other. Stability mark (→): Lights when the displayed value falls within the stability band. When the load change is slow, the displayed value will fluctuate with the stability mark lit.
PRECAUTIONS:
- Do not weigh on the pan directly. Always use butter paper.
- Do not place heavy glassware on the pan. It may damage the instrument
- Do not weigh corrosive acids & hot materials. > Do not shift the balance once positioned
- Do not give a shock to the pan.
- Do not open the balance case.
- Do not expose the balance to anything magnetized.
- Do not connect anything other than the specified equipment to the connector on the rear side of the balance.
- After completion of weighing keep the inside area clean.
REFERENCES: Instrument Manual