OPERATION AND CALIBRATION OF PH METER

I.         PURPOSE

To define the Standard Operating Procedure for Cleaning of Sparkler Filter.

II.       SCOPE

This procedure is applicable for Sparkler filter used in Production Department at Unit-V.

III.      RESPONSIBILITY

Assistant , Executive - Production

IV.      ACCOUNTABILITY

Head - Production

V.                PROCEDURE    

1.0        Preparation of buffers

1.1       pH 7.0

1.1.1        Dissolve one tablet / Capsule of pH 7.0 buffer in 100ml of distilled water and see the pH at 20°C.

1.1.2        The pH should be 7.0.

1.2        pH 9.2

1.2.1        Dissolve one tablet / Capsule of pH 9.2 buffer in 100ml of distilled water and see the pH at 20°C.

1.2.2        The pH should be 9.2.

1.3        pH 4.0

1.3.1        Dissolve one tablet / Capsule of pH 4.0 buffer in 100ml of distilled water and see the pH at 20°C.

1.3.2        The pH should be 4.0.

1.4        Prepared buffers should be given use before date for one week, if any growth observed       before use before date, discard the solution and prepare new solution.

2.0        Operation of pH meter

2.1            Ensure that the working area and the instrument is clean.

2.2            Check the calibration status of the instrument.

2.3            Switch on the instrument.

2.4            Ensure the electrode is properly connected.

2.5            Clean the electrode thoroughly with purified water and wipeout using tissue paper.

2.6            This cleaning procedure should be followed at each time of measurement.

2.7            Take the sample solution in a clean dry beaker.

2.8            Set the temperature as per sample specification.

2.9            Mix the sample thoroughly and place the electrode in the sample solution. The pH will be displayed and note the pH value.

2.10        After measuring the pH clean the electrode with purified water.

2.11        Always keep the electrode in distilled water.

2.12        Switch off the instrument when it is not in use.

2.13        Electrode Maintenance

2.13.1             Inspect the electrode frequently for scratches, membrane coating, and salt crystal buildup.

2.13.2             Rinse off salt deposits or membrane deposits with purified water.

2.13.3             If rinsing with purified water does not remove the deposits, then soak the electrode in 0.01M HCl or 0.1M HNO₃ for 30 minutes and finally rinse with purified water.

2.13.4             If the reference electrolyte appears to be contaminated with extraneous matter drain the reference electrode chamber.

2.13.5    Press the CAL/ PRT Button.           

2.13.6    Instrument displays ‘CAL 2’ , press YES.

2.13.7    Now it displays pH Cal 2, Buffer 1 RDY, press YES.

2.13.8    Keep Buffer 7.0 and press YES.

2.13.9    Now it displays buffer 2 RDY.

2.13.10Remove the solution and clean the Electrode with distilled water and wipe with tissue.

1.1          Keep Buffer 4.0 and press YES.

1.2          System displays the pH value of 4.0 Acceptance limit is 4.0   ± 0.02

1.3          Keep the 9.2 buffer after cleaning  the electrode.

2.0       Interpretation of Results

2.1          If the calibration results are found satisfactory, then the instrument can be used     for testing.

2.2          If the results are found out of limits, adjust the slope of the instrument and            recalibrate.

2.3          If the problem still persists follow the under given procedure. Investigate as per     OOS.

2.4          After OOS investigation, if the calibration results are not satisfactory affix             ‘Out     of  Calibration’ Label on the instrument.

2.5          Call the service engineers to rectify the instrument.

2.6          After rectification, calibrate the instrument.

3.0        Frequency

            At the beginning of each shift

           

VI.       REVISION SUMMARY

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