Peak Instruments P-311 Pocket Conductivity Meter use a pH meter, the pH electrode is first calibrated with standard buffer solutions with known pH values that span the range being measured. To make a pH measurement, the electrode is immersed into the sample solution until a steady reading is reached. A pH meter consists of a voltmeter attached to a pH-responsive electrode and a reference (unvarying) electrode. The pH-responsive electrode is usually glass, and the reference is usually a silversilver chloride electrode, although a mercurymercurous chloride (calomel) electrode is sometimes used.

• IP57 waterproof and easy-to-read LCD screen, replaceable electrode. There are calibration solution, electrode soak solution and backup batteries.