How do electrochemical sensors work?
Electrochemical sensors use chemical reactions to measure the concentration of specific gases in the environment. Electrochemical sensors have many different applications, and they continue to play an important role in many industries. In this blog post,
Electrochemical sensor technology has been used in industry for many years. Current requirements for small sensors with low energy consumption and ease of use have enabled the continuous development of this technology. Electrochemical sensors can be constructed in different ways depending on the application, thus enabling tailor-made solutions for emerging applications.
The composition of the electrochemical sensor
Electrochemical sensors work by reacting with a gas of interest and producing an electrical signal proportional to the gas concentration. The sensor consists of two electrodes (a working electrode and a counter electrode) and works by passing charged molecules through a thin electrolyte.
*Breathable Membrane - This material covers the sensing electrode and is used to control the number of gas molecules reaching the electrode surface. This membrane also plays an important role of filtering unwanted particles.
*Electrode (Anode) - In order to react efficiently with gas molecules, the electrode is usually made of a metal such as platinum or gold and used as a sensor. The anode is the point where the current enters the electrode.
*Electrode (Cathode) - This is where the current leaves the electrode.
*Electrolyte - Electrolyte facilitates battery reactions and carries ionic charge across the electrodes.
Often referred to as the "fourth industrial use," compressed air provides the power that drives many different industrial processes and systems, from pneumatic tools and material handling equipment to food preparation and waste recycling units. Depending on the application requirements, electrochemical sensors detect and measure a variety of gases, including oxygen, carbon monoxide, nitrogen dioxide, nitrogen oxides, and sulfur dioxide.
The accuracy of the electrochemical sensor is very high
Electrochemical sensors are very accurate and can measure oxygen levels down to parts per million (ppm) levels. This makes them an important sensing technology in many different industries, including hospitals, factories and environmental monitoring. Different applications have different requirements, but typically the sensor will only operate in applications with pressures from 0-100mbar.
As the lead anode oxidizes due to electrochemical reactions, the electrical/chemical characteristics of the battery change and require periodic calibration. Once all available lead is oxidized, the battery will no longer produce output and must be replaced. Therefore, the lower the oxygen level the sensor is exposed to, the longer it will run. Oxidation of the lead anode also means that the oxygen analyzer sensor has a limited lifetime. If the sensor is not replaced or recalibrated, the accuracy of the output will be greatly reduced.