Tests on Water
pH value Test
This test is done as per Instrument Manual.
Procedure:
- (i) Prepare 7 pH and 4.0 or 9.2pH solution using tablets. Wash the electrodes with distilled water and dry it with tissue paper.
- (ii) Connect the electrodes to the pH meter. Dip the electrodes in 7 pH buffer solution, set the TEMP control as per the temperature of the solution. Set the function selector in pH mode. The pH LED should glow. The meter will give some reading near 7.0 pH, say it gives 6.7pH. Use STANDARDIZE control to make the reading exactly 7.0.
- (iii) Remove the 7.00 pH solution. Wash and dry the electrodes as instructed earlier. Take 4.0 pH buffer solution and dip the electrode in it. See the digital Display, say it reads 4.2 pH. The error is 0.2 pH. Now use the SLOPE control to adjust the pH reading 4.00 pH. The pH meter is now standardised and hence do not disturb any control.
- (iv) To measure the pH of an unknown solution, immerse the electrodes in that solution and set the TEMP control as per the temperature of the solution and directly read its pH value. Every time the electrodes have to be washed and dried as instructed above.
Uses:
It is used to determine pH value of water.