- Objective:
- To lay down a procedure for calibration of pH Meter.
- Scope:
- This SOP is applicable for calibration of pH Meter in quality control laboratory.
- Responsibility:
- Officer or above of QC laboratory is responsible for calibration of pH Meter
- Head Quality / nominee of QC department is responsible for reviewing and approval of the SOP
- Accountability:
- Head – Quality Control shall be accountable for compliance of SOPs.
- Procedure:
- Ensure the cleanliness of the instrument.
- Clean the electrodes with purified water and wipe with tissue paper.
- Dip the electrode in pH-7.0 solution and press the CAL 7 key. The message ‘ENTER IF STABLE ‘will show then press the ENTER key and record the results.
- Dip the electrode in pH -4.0 solution and press the CAL 4 key, the message ‘ENTER IF STABLE’ will show then press the ENTER key .
- Dip the electrode in pH -9.2 solution and press the CAL 9.2 key, the message ‘ENTER IF STABLE’ will show then press the ENTER key .
- The message will show ‘Calibration complete.
- While checking the pH of buffer 4.0, and 7.0 clean the electrode with purified water every time.
- After use keep the electrode dipped in the purified water.
- Calibrate the instrument daily and record the results in the format as per Annexure- I.
- Maintain the preparation and consumption record of pH buffer solution as per Annexure- II.
- If the results of calibration are not conforming to the specified limits report to the department Head for an appropriate action.
List of Annexure
| S.No. | Annexure Title | Annexure Number |
| 1 | pH Meter Calibration Record |
I |
| 2 | Preparation and consumption record of pH buffer solution |
II |
- References (if any).
- Not applicable.
- Reason for Revision
- Not applicable due to first version.
Annexure – I
pH Meter Calibration Record
MAKE : MODEL :
|
Date |
Standard Buffers |
Done By |
Checked By |
|||
| 4.0 | 7.0 | 9.2 | ||||
| Limit | ± 0.05 | ± 0.05 | ± 0.05 | |||
Annexure – II
Preparation and consumption record of pH buffer solution
|
Date of preparation |
Opening Balance | Buffer tablet/Capsules (Qty. used) | Balance Qty. |
Prepared by |
Checked by
|
||||||
| 4.0 | 7.0 | 9.2 | 4.0 | 7.0 | 9.2 | 4.0 | 7.0 | 9.2 | |||
