What Is an ORP Sensor and What Does It Do?

When analysing water quality, it’s critical to understand oxidation reduction potential (ORP) and what this number means. Oxidation reduction potential is a form of measurement that determines a substance’s capacity to decrease or oxidise another chemical. You may take oxidation reduction potential measures in water and similar solutions by the electrodes within an ORP sensor. When the ORP sensor returns a negative signal, it indicates that the measured material is a reducing agent. Positive results, on the other hand, show that the liquid is an oxidiser.

Before you begin checking the quality of the water, you need to know what reduction and oxidation are. Oxidation is a chemical process that happens when a material lacks electrons and must obtain them from another component in the solution. When employing an ORP sensor, these compounds will provide positive results, so they are classified as oxidising agents. When electrons have an excess of ions, they may be able to supply some to various oxidising agents. These are known as reducing agents because they invariably generate negative oxidation reduction potential values.

An ORP meter will inform you if the water is polluted or sanitised when checking the water quality.. If water is sanitised for recycling or consumption, the oxidation reduction potential value of the sterilised water will be increased. Contaminated water, on the other hand, typically has low ORP values. There are two separate electrodes in an oxidation reduction potential sensor, which is similar in concept to a pH sensor.

Among the two electrodes are a reference electrode and an oxidation reduction potential electrode (ORP). When an ORP electrode is immersed in a solution, it either accepts electrons from a reduction agent or gives electrons to an oxidising agent. You will continue this approach until you acquire a measurement that equals the precise ORP of the solution.

What Is an ORP Sensor’s Purpose?

A good understanding of oxidation reduction potential is necessary when judging the quality of water or a comparable solution. This examination can tell you whether one medicine can diminish or oxidise the effects. If you get a high ORP meter, make sure the fluid in which the ORP sensor is submerged contains an oxidising agent. Lower values reveal the contrary to what is expected.

There are several applications for the oxidation reduction potential measurement, the most important is to evaluate how contaminated or sanitised water is. Whether you want to ensure that the water is safe to drink or that the heating water is free of impurities, the ORP measurements will give you all the information you need to decide if extra sanitation or disinfection is necessary for your facility. Water needs to have a high oxidation reduction potential grade to be safe to recycle or consume. If the water has been properly sterilised, it has been thoroughly sterilised.

When water is declared safe to drink, its ORP value typically varies between 200 and 600mV. Readings that exceed -100mV, on the other hand, suggest that the water may be too polluted to drink. Without these values, it might be impossible to determine how polluted, or sterilised water is. ORP tests are significant for ensuring that the water is almost free of pollutants. While disinfected water has an ORP measurement of roughly 600-700mV, thoroughly sterilised water has an oxidation reduction potential reading that exceeds 800mV. Understanding the many reasons that might cause ORP readings to change can help you determine why your water quality is changing.

What Do ORP Sensors Look For and What Do They Measure?

ORP sensors have the ability to offer a wide variety of measurements that are relevant in a wide range of applications, and they are becoming increasingly popular. In the majority of cases, ORP sensors are used in the following applications:

  • Cooling towers
  • Disinfection and chlorine
  • Poultry processing
  • Pulp bleaching
  • Swimming pools
  • Water purification

The oxidation reduction potential (ORP), which is often used to determine water quality in chlorinated swimming pools, is particularly relevant when considering swimming pools in general. Because every component in the water immediately impacts oxidation reduction potential, an ORP sensor can give you information that you wouldn’t get from pH sensors alone. A pH sensor can only detect hydroxide ions and hydrogen ions, and it cannot see any other ions. If you have a bigger pool in your yard, there’s a good chance it’s already equipped with an inline ORP sensor. If it doesn’t, there are a variety of portable oxidation reduction potential sensors available.


ORP sensors can supply you with more information than you can acquire from a pH sensor alone, which is why an ORP meter is highly significant when evaluating water quality. If you’re purifying water and want to ensure that the substances you’re utilising have the desired impact, utilising an ORP sensor to test the water will provide you with all of the data you need to make a choice.