Instruments used to measure the acidity or alkalinity of a sample, and designed for portability and durability.

Portable pH meters are most often used away from the physical lab to measure the acidity or alkalinity of liquids in more remote locations.

A pH meter actually measures hydrogen-ion activity in water-based solutions. The liquid’s acidity or alkalinity is expressed as a pH unit. The pH scale ranges from 0 to 14, meaning a liquid with a pH below 7 is acidic and a pH above 7 is basic. A pH of 7 is considered neutral.

Also called electrochemistry meters, pH meters are potentiometric and determine the difference in electrical potential between the measuring electrode and a reference electrode.

Some portable pH meters accomplish routine tasks, often used to determine the pH of swimming pools and meet other commercial needs. These are sometimes called pH testers. Indicators or litmus papers can also be used to qualitatively measure pH.

Modern portable pH meters are typically digital and may detect more than pH. Some are equipped to measure specific ions, dissolved oxygen content, or conductivity.

Many portable pH meters are waterproof to protect against accidental dropping or adverse environmental conditions like rain or snow. Some electrodes are also equipped with longer cables to allow for submersion in a reservoir of water or other liquid.