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Published On: May 10th, 2022

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The principle behind pH meters hasn’t changed since they were first designed in the 1930s, but the technology has improved, and there is now a wide range of automated pH meters available that can speed up the pH measurement process. Get ready to become a pH expert!

Read on to learn more about pH meter principles and applications, how a pH meter works, and how to choose a pH meter for a lab.

What is a pH Meter?

Before exploring pH meter principles and applications, it’s time to review what a pH meter does. A pH meter measures the acidity or alkalinity of a solution. Acidic solutions have positively charged hydrogen ions, and alkaline solutions have negatively charged hydroxide ions.

pH stands for the power of hydrogen, and it is calculated based on the number of hydrogen ions in a liquid. Because these hydrogen ions create a positive charge, an acidic solution with many hydrogen ions can easily conduct an electric current. pH meters measure that ability.

What is the Working Principle Behind Lab pH Meters?

The working principle behind pH meters is potentiometry. This is the measurement of a solution’s electric potential (voltage). Remember how acidic solutions can efficiently conduct an electric current because of the positive hydrogen ions? The ability of a solution to conduct a current is called electric potential. Electric potential is key in understanding pH meter principles and applications.

A pH meter measures electric potential using 2 electrodes inserted into the liquid to create an electrical circuit. One of these electrodes, called the reference electrode, will contain a substance with a known electric potential. The other electrode, known as the sensor electrode, will be inserted into the solution being tested. The electric potential is the difference that results from comparing the reference electrode to the sensor electrode.

What Are the Most Common Applications of pH Meters?

pH meters have a wide range of industrial applications ranging from medical to industrial. Measuring the voltage of a solution is the pH meter principle and applications all involve liquids as a result. pH meters are used in the development of pharmaceutical drugs since acidity can affect drug metabolism. In agriculture, pH meters are important for testing soil and water quality. Water purification plants use pH meters to validate filtration methods. pH meters measure water safety in pools and aquariums. pH meters are also used to develop food, cosmetics, and detergents.

How to Choose a pH Meter

Understanding the pH meter principle and application can be useful when choosing the right pH meter for a lab. Consider the compliance requirements, throughput targets, and workspace dimensions. Hudson Robotics offers pH meters designed for CFR 21 Part 11 compliance, compact benchtop pH meters, and automated pH meters.

Whether it’s a small classroom lab or a full-scale industrial operation, there is a solution to fit that lab. Contact Hudson Robotics today to find the pH meter that best suits the lab’s needs.