SOP for Operation and Calibration of the DBK Digital pH Meter

OBJECTIVE 

To lay down a procedure for the Operation and Calibration of the DBK Digital pH Meter.

SCOPE 

This procedure applies to the pH Meter installed in the Quality Control Department, at XYZ Limited. 

RESPONSIBILITY 

Execution: Chemist and above – QC department. 

Checking: Asst. Manager and above – QC department 

PROCEDURE

OPERATIONAL PROCEDURE 

• Ensure that the instrument is clean and free from dust. 
• Press the power ‘ON/OFF’ switch at the rear panel to the ‘ON’ position. 
• Connect the electrode to the appropriate terminals at the rear panel. 
• Press the “Stand-by”/”Read” button to read the pH of the solution. 
• When not in use Keep the apparatus in Stand By mode and store the electrode in 4M KCl solution.

CALIBRATION PROCEDURE 

Frequency: Daily 

• Connect the combination pH electrode and the temperature probe to the input socket. 
• Switch ON the mains. 
• Switch ON the instrument. 
• Wash the electrode already dipped in KCl solution with distilled water 
• Dip the electrode in 7.0 pH buffer. 
• Adjust with the ‘CALIBRATE’ control knob till the digital display shows the precise pH value of the buffer solution.

ALSO READ: SOP for Operation and Calibration of pH Meter Model- Hi 2211

• Now move the function electrode switch to the ‘STD BY’ position. 
• Remove the electrode from the buffer solution and wash it with distilled water. 
• Dip the combined electrode into another buffer solution (say 4 pH). 
• Set the function electrode switch to ‘pH’ position 
• Adjust the slope correction control on the instrument's front panel until the instrument shows the pH value of the selected buffer solution. 
• Repeat the above steps for pH measurement of buffer solution 7.0 
• Record the observation in the annexure Annexure-01. 
• When not in use store the electrode in 4M KCL solution. 
• Acceptance Criteria: ± 0.05 pH 

ANNEXURE

Annexure No. - 1 -- Daily Calibration Record of pH Meter

REFERENCE

Nil. 

ABBREVIATION

SOP: Standard Operating Procedure 

Q.A: Quality Assurance 

Q.C: Quality control 

REVISION HISTORY

Nil

ALSO READ: SOP for Cleaning of pH Meter