Procedure for Operation & Calibration of  pH Meter

Reshma Verma
STANDARD OPERATING PROCEDURE
Title : Procedure for Operation & Calibration of  pH Meter

 
  •    OBJECTIVE
    • This SOP describes the procedure for operation and calibration of pH Meter.
  • SCOPE
    • This procedure is applicable for operation and calibration of pH Meter in Quality Control Department.
  • RESPONSIBILITY
    • Officer / Executive-QC – responsible for Implementation of SOP.
  • ACCOUNTABILITY
    • Manager Quality Control
  • PROCEDURE
  • Operation
    • Before operating the instrument, clean the instrument properly.
    • Place the instrument on clean and flat surface near a power point.
    • Connect the unit to 230 V mains power supply.
    • Switch on the mains.
    • Press the ON/OFF key, pH meter automatically starts in last mode of operation.
    • Rinse the electrode with purified water & wipe the electrode.
    • Dip electrode in sample & show the pH.
    • After completion of pH clean the instrument.
    • Record the activity of instrument in log book of pH meter.
  • Calibration
    • PH meter calibrated daily with pH 4.0 and 7.00 buffer solutions.
  • Preparation of Buffer Solutions
    • Collect the tablets and follow the instruction as per manufacturer in this bottle for buffer solution pH 4.0 and 1.0.
    • Prepare the buffer solution after every 07 days. If there is any change in physically appearance, make the fresh buffer solution.
  • General Instructions
    • Check the validity of the buffer solutions before use.
    • After calibration do not switch off the pH meter. If done so, again calibrate the pH meter before use.
    • To remove excessive water from the electrode gently touches it over with a small piece of tissue paper. Never rub the electrode with tissue paper.
    • If pH meter is not in use for more than 48 hours, then immerse the electrode in saturated Potassium Chloride solution for one hour before use.
  • Calibration Procedure
    • Press the ON/OFF key, pH meter automatically starts in mode of operation.
    • Rinse the electrode with purified water and wipe the electrode.
    • Transfer approx. 50ml each buffer solution from stock buffer solution in 100 ml capacity dry beaker.
    • It will show “MEAS” on the top of display screen.
    • Press once again on/off button, it will show “CAL”. Wash the electrode & Dip in the buffer solution pH: 7.0 and wait till the upper value get stabilize and show ready mode.
    • Press enter. It will calibrate the value.
    • Take out and wash the electrode. Put it in buffer solution pH: 4.0 and wait till the upper value get stabilize and show ready mode.
    • Take out and wash the electrode.
    • Electrode should be always dipped in saturated KCL.
    • Fill the Calibration status label Format and affix it on the instrument.
    • Report any discrepancy observed during calibration of instrument to Quality Control In-Charge or his designee for corrective and preventive action.
    • Calibration should be required after maintenance.
  • Precaution and Cleaning:
    • Wash the electrode and reference junction in purified water.
    • Do not leave the electrode dry; keep the electrode in saturated KCl.
    • Do not wipe the glass electrode bulb with any coarse material. Use only tissue paper.
    • Dissolve the salts deposits by immersing the in a container filled with some tap water for ten to fifteen minutes. Then thoroughly rinse with purified water.
  •     ABBREVIATION

     SOP      –  Standard operating procedure

     QC       –  Quality Control

  •   FORMAT

NIL

  •    DISTRIBUTION LIST
Sr. No. Copy No. Department
Quality Assurance
Quality Control

 

SOPs