The standardization of a pH meter is important to ensure that the readings returned from that meter are accurate. Digital & analog pH meters offer calibration buttons or dials that are used to adjust the sensitivity of the meter. Over the course of standard usage, laboratory equipment, such as a pH meter, loses accuracy and requires standardization. Standardization should be performed regularly.
- Standardization solutions (solutions of known pH)
- De-ionized water
- Paper towels
When selecting standardization solutions, it is important to select both basic and acidic solutions. This ensures that both ends of the reading spectrum are properly calibrated.
It is important to thoroughly rinse and dry the reading end of the pH meter between readings. This ensures that the standardization solutions are not contaminated and prevents erroneous readings.
Place the reading end of the pH meter into a standardized solution.
Compare the reading on the meter with the known pH of the solution.
Use the calibration buttons to change the reading on the meter until it matches that of the standardized solution.
Rinse the reading end of the pH meter generously with the ionized water and dry with paper towels.
Repeat this process with several standardized solutions to ensure the accuracy of the pH meter.
Things You'll Need
- "Chemistry, 5th edition"; John E. McMurry, Robert C. Fay; 2008
- "Chemistry the Central Science, 11th edition, Laboratory Experiments"; John H. Nelson, Kenneth C. Kemp; 2009
- Thinkstock Images/Comstock/Getty Images