How to Pick the Right pH Testing Equipment

Posted in: Applications, OEM Sensors

Author: Sentek Ltd

Date Posted: 22/09/2017

Most people, even if they don’t work in a specialist profession, have a bit of knowledge about pH and its significance. It is one of the first lessons taught in school chemistry because knowing how to measure acidity and alkalinity is relevant to all kinds of scenarios. Ultimately, pH plays a vital role in many different aspects of life, so it’s a very useful tool.

The range of businesses which utilise pH testing equipment is surprisingly broad. The food and drink industry is one of the biggest clients, but the cleaning sector comes a close second. Everything from scrubbing carpets to washing swimming pools requires just the right pH balance for success. It is why high quality pH probes and electrodes are always in demand.

If your business is in need of premium testing equipment, the first step is working out what kind of pH probe or other instrument you require. Keep reading to find out more.

The Makeup of a pH Probe

From a technical perspective, pH probes and electrodes have changed very little over the decades. The basic internal setup is the same, though advanced features and new additions have been used to extend their value.

Inside the probe, there is a reference solution. This is made up of silver or potassium chloride. It is designed to provide a constant electric potential so that the probe can identify the potential in the sample and calculate the difference between the two. This gives the pH reading.

Electrodes and probes are very delicate things. They must be cared for and maintained in a specific way, in order to guarantee accurate measurements. Some, like glass bulb probes, are actually reusable as long as the reference solution is refilled at the right times.

The Different Types of Probe Available

Today, there are all kinds of pH probes on the market, and they are suited to a wide variety of applications. They include combination, gel filled, double junction solid state, ion selective, epoxy body electrodes, and more. Let’s take a closer look at some of these tools.

Single Junction

This is the most common probe, so it is considered to be the ‘standard’ choice. It contains that all-important silver chloride reference solution, and it is compatible with everything but heavy metal samples (like iron or lead), proteins, sulphides, organics, and low ion concentrations.

Double Junction

The double junction works in much the same way as the single junction, but it contains two reference channels. The purpose of this is to filter contaminants out of the reference solution. So, silver chloride can be used with heavy metals, but only when part of a double probe.

PTFE Resin Junction

This next pH probe is a very specialist instrument. It is primarily used in situations where the sample may cause obstructions. So, for example, testers of paint, sauces, and other types of paste use these for quality control procedures. They are highly resistant to clogs and jams.

For more information on pH testing and the use of pH probes, contact us or, call 01376 430 456 to place orders for high quality conductivity, reference, and pH electrodes.

Back to All Articles

Copyright 2024 Sentek Limited. All Rights Reserved.

Marketing by Unity Online