Calibration of pH Meter | Quality Assurance B.Pharmacy 6th Semester

 Calibration of pH Meter in Quality Assurance B.Pharmacy 6th Semester

CALIBRATION OF pH METER 

B.PHARMACY 6 TH SEMESTER SDPGIPS Rohtak

1 A pH meter is an electronic instrument used for measuring the pH (acidity or alkalinity) of a liquid (though special probes are sometimes used to measure the pH of semi-solid substances).

A typical pH meter consists of special measuring probes (a glass electrode and a reference electrode) connected to an electronic meter that measures and displays the pH reading. 

INTRODUCTION SDPGIPS Rohtak 

2 pH is defined as the negative logarithm of hydrogen ion concentration.

pH= -log [ H+ ]  p = power  H = hydrogen  [H+ ] = hydrogen ion concentration

The pH of a solution can be measured by the pH meter. The glass electrode is an half cell and the calomel electrode is another half cell. PRINCIPLE SDPGIPS Rohtak 

3 WHAT IS CALIBRATION 

Calibration is the act of ensuring that a method or instrument used in measurement will produce accurate results.

Calibration is performed using primary reference standard SDPGIPS Rohtak

4 NEED OF CALIBRATION 

When a specific time period is elapsed. 

When a specific operating hours has elapsed. 

With a new instrument.

When observations appear questionable. 

SDPGIPS Rohtak 

5 PARTS OF DIGITAL PH METER

pH electrode Device have 4 knobs

6 FUNCTION MODE Function Mode pH Mode (used to measure pH by rotation) Standby mode MV Mode (used to measure mv) • Temperature settling knob: To set temperature • Calibration knob: rotate to adjust and set Ph value to standard pH value SDPGIPS Rohtak 

7 PROCEDURE  First of all, calibrate the pH meter. & prepare standard buffer solition of pH 4 and ph 7 (calibratin by standard buffer solution of pH7)  First dip electrode in standard buffer solution of pH 7  Then set temperature at 25°c by rotating temperate knob.  Rotate the function knob to pH mode.  And wail for constant display reeding.  Rotate calibration Knob to the right display reading become 7.  Rotate function knob to standby mode and Remove electrode from solution  Then rinse electrode with distilled water and dry it with tissue paper. SDPGIPS Rohtak 

8 PROCEDURE  Calibrate the pH meter. & prepare standard buffer solution of pH 4 and pH 7 (calibration by standard buffer solution of pH4)  First dip electrode in standard buffer solution of pH 4  Then set temperature at 25°c by rotating temperate knob.  Rotate the function knob to pH mode.  And wail for constant display reeding.  Rotate slope Knob to the right display reading become 4.  Rotate slope knob to standby mode and Remove electrode from solution  Then rinse electrode with distilled water and dry it with tissue paper. 

SDPGIPS Rohtak 

10 Thank you