What do I need to do to check that my pH meter is functioning correctly

To have full confidence in your pH measurements it is essential that you can demonstrate that each component of the measuring system is functioning to specification. If any component of the measurement system does not meet this requirement, questionable results will be obtained. For pH measurement, the following must be verified:·

• The pH meters ability to correctly process both pH and temperature inputs correctly
• The pH electrodes ability to generate the correct output signal
• The temperature sensors ability to generate the correct output signal

Routine calibration using pH buffers will not demonstrate all of the above, this is why annual calibration should be performed.