The primary pH meter validation and verification tests are:
The pH meter must be calibrated before usage for reliable readings. Use standard buffer solutions with known pH values.
Comparing the pH meter’s values to a reference pH meter (or) verified reference material helps establish its accuracy.
Measure the pH of a sample numerous times and calculate the standard deviation to estimate the pH meter’s precision.
The pH meter’s linearity can be determined by measuring solutions with different pH levels and plotting a calibration curve.
Measure the pH of a solution over time & track any changes to verify the pH meter’s stability.
ASTM E70-07 - Standard Test Method for the pH of the Aqueous Solutions With the Glass Electrode validates pH meters.