CLEANING, OPERATION, PRECAUTION, MAINTENANCE & CALIBRATION OF pH METER
CLEANING, OPERATION, PRECAUTION, MAINTENANCE & CALIBRATION OF pH METER
PURPOSE : To establish written procedure for cleaning, operation, precaution, maintenance & calibration of pH meter.
SCOPE : This SOP shall be applicable for cleaning, operation, precaution, maintenance & calibration of pH meter at SVP section
REFERENCE(S)
User Manual of pH meter
CROSS REFERENCE DOCUMENTS
Document(s) and Data Control Procedure
Training Program for Employees
Preparation, review, approval, issuance & retrieval of standard operating procedure (sops)
ATTACHMENTS
Calibration Record of pH meter – Attachment-I
Buffer Solution preparation Record – Attachment-II
Definitions
pH meter: A pH meter is a scientific instrument that measure the hydrogen ion activity in water based solution, indicating its acidity & alkalinity expressed as pH .The pH meter measure the difference in electrical potential between a pH electrode & a reference electrode, so the pH meter is some time referred as potentiometric pH meter. A pH meter contain a pH probe that the electrical signal to pH meter & pH meter display the pH value of solution. The glass pH probe contain two electrode, a sensor electrode & a reference electrode. These electrodes are in the form of glass tubes, on contain pH 7 buffer & other contain saturated potassium chloride.
ABBREVIATIONS
cGMP : Current Good Manufacturing Practice
SVP : Small Volume Parenteral
WFI : Water For Injection
KCL : Potassium Chloride
HCL : Hydrochloric Acid
RESPONSIBILITY
Production department shall be responsible:
Preparation of the SOPs.
To perform the operation, cleaning of instrument as per the respective SOP.
To perform the daily calibration as per SOP.
To maintain the record.
To maintain the buffer solution for instrument calibration.
To provide the training of the SOP to concerned personal.
To co-ordinate with QC for buffer solution on routine basis..
To follow the described here in.
Head of production department/designee shall be responsible for:
Ensure that sub-ordinate, operators are trained before performing any task or operation.
To check the SOP for proper contents/technical parameter as per the equipment.
To get the SOP approval from Quality Assurance or designee.
To provide the training of SOP to the concerned personnel before effective date of the SOP.
To ensure implementation of the SOP on effective date.
To verify that instrument is in proper working condition.
To co-ordinate with supplier or external agencies for perform maintenance or calibration.
To verify the calibration records on routine basis.
Quality Assurance department shall be responsible for:
To verify that all content of SOP are relevant to the concern equipment & process.
To maintain the approved master copy of the SOP of all department for document control.
To issue the required number of controlled copies to the departments and document the same.
To verify that all the instructions are followed properly as per the given SOP.
To ensure implementation of SOP.
To verify that calibration records are maintained as per defined system.
To verify instrument is calibrated before operation.
o verify that instruments is in proper working condition before performing any task.
Head – Quality Assurance/ Designee shall be responsible for:
To approve new or revised SOP.
To verify employees are trained before performing any task.
Final approval of the SOP by signing off as approved by.
o ensure the implementation of the defined system.
To verify the buffer solution.
To verify the data integrity of records.
Plant Head shall be responsible for:
o approve new or revised SOP.
o ensure the implementation of the defined system.
ROCEDURE:
SAFETY/PRECAUTION/EHS
Electrode of pH meter is sensitive made up of glass so don’t treat it with hard hands.
Always keep the electrode wet & dipped in purified water or WFI.
Don’t use the vacuum cleaner where any flammable liquid are stored.
Switch off the instrument during cleaning.
Keep the instrument in clean & dry place.
Don’t strike the electrode on hard surface.
CLEANING
During cleaning ensure that instrument is in switch off condition.
Wipe the instrument with dry lint free cloth.
If any dirty spot found on the body of pH meter clean it with Colin.
After every time of usage of instrument wash the electrode with WFI or purified water followed by tissue paper.
OPERATION OF pH METER
Ensure instrument is kept on smooth surface.
Connect the power cable of instrument with MAINS power supply.
Switch “ON” the MAINS.
Switch “ON” the instrument & wait for 10 second for warming up the instrument.
After cleaning switch “OFF” the vacuum cleaner and remove the accessories attached for cleaning.
Ensure that the instrument is calibrated. If not, calibrate the instrument first before starting the operation.
Wash the electrode with distilled water and wipe gently with tissue paper.
Take the sample solution in glass beaker & allow to attain the temperature up 25°C ±2° C or the specified temperature.
Dip the electrode in the test solution of which pH to be measure. Ensure that bulb of the electrode is properly dipped in solution.
Keep the instrument in “MEAS” mode & instrument will measure the temperature & pH of the same solution.
Allow the solution to stabilize the pH with the electrode & Note the stable reading displayed on the digital display.
Lift the electrode carefully and wipe gently with tissue paper.
Always immerse the electrode in the 3 M KCL solution, if not in use.
KEY FUNCTIONS
CAL : To perform CALIBRATION within the selected operating Mode.
HOLD : To freeze the measured reading. Press again to resume live reading.
MODE : Toggles between available measurement modes, pH/Temp, mV/Temp.
ENTER : To acknowledge the entered value.
MEAS : To measure the pH & temperature.
MI: MI (memory insert) store values in memory.
MR : MR (memory recall) recall values from memory.
CALIBRATION OF pH METER
Calibration of pH meter to be performed with different pH (acidic, alkaline & neutral) buffer solution.
Readymade buffer capsule or QC prepared buffer solution of (pH=4.0, pH= 7.0 & pH =10.0) used to prepare buffer solution.
Buffer solution will be readily prepared in production department on weekly basis or whenever necessary.
To prepare buffer solutions of pH 4.0, collect 25 ml WFI (20-25ºC) in a measuring cylinder & collect one buffer capsule of pH 4.0 from the bottle & open the capsule by twisting & pulling apart carefully & transfer the powder of capsule in WFI of measuring cylinder & dissolve it properly & finally make up volume 100 ml with cool WFI & transfer the same in screw cap borosil bottle.
Fix the label on the bottle bearing buffer solution name, preparation date, used date, prepared by & checked by.
Follow the same procedure to prepare pH = 7.0 & pH = 10.0 buffer solution.
To calibrate pH meter rinse the electrode of pH meter with WFI & remove the excess water with tissue paper & clean the temperature sensor also with WFI.
keep the instrument on “CAL” mode & press “CAL” key of the instrument.
Instrument will demand for pH 7.0 buffer.
Dip the electrode & temperature sensor in prepared first buffer solution A (7.0) pH value & allow to stabilize the measuring value of the buffer.
As the displayed measured value get stable press enter & instrument will demand for either 4.0 pH buffer or 10.0 pH buffer.
Rinse the electrode with WFI & soak the excess water with tissue paper.
Dip the electrode in buffer (4.0) pH value allow to stabilize the measuring value of the buffer.
After stabilization of second buffer, press enter, remove the buffer & rinse the electrode with WFI & soak the excess water with tissue paper.
Dip the electrode in third buffer (10.0) pH value & after stabilization the same buffer press enter.
Wash the electrode with WFI & press the “MEAS” to verify the proper calibration of Instrument.
Mention the observed pH value data of calibration in the calibration record.
Calibration frequency: Daily before use or whenever necessary.
Never use expired buffer solution of calibration of pH meter.
MAINTENANCE
If electrode damage, then production person will give request to vendor or supplier for new electrode & fix it & before use charge it by dipping it in KCL solution for 24 hours.
If the adopter of instrument not working, production person will inform to engineering person to replace with new one.
During maintenance work always switch off the instrument.
If the instrument shows error during measurement or showing fault reading, production person will contact to supplier for the rectification or maintenance of the same & until that time use any other calibrated pH meter on the basis of deviation.
INSTRUCTIONS FOR STORAGE AND REACTIVATION OF pH METER
ELECTRODE
Whenever required, fill the electrode with saturated solution of “KCl” below the filling hole.
Never touch the lower sensitive bulb of the electrode by hand or any other hard surface.
For reactivating the electrode, dip electrode in 0.1 N HCl for overnight whenever required.
Use electrode very carefully.
Whenever required change the electrolyte of electrode and KCL solution in which the electrode remains dipped.
Always keep electrode in 3M KCL when pH meter is not in use.