Unless otherwise prescribed in the monograph, all measurements are made at the same temperature (20-25 °C).
Rinse the pH sensor with water, then with a few portions of the test material.
Immerse the electrodes in the solution to be examined and take the reading in the same conditions as for the buffer solutions of calibration.
All solutions to be examined shall be prepared using carbon dioxide-free water R, If the pH of the test sample is sensitive to ambient carbon dioxide, then use Purified Water that has been recently boiled, and subsequently stored in a container designed to minimize ingress of carbon dioxide.
Place the electrode into sample. When “ready” is displayed besides the reading, record the sample results.