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How does an electrochemical gas sensor work?

How does an electrochemical gas sensor work?

These electrodes are enclosed in the sensor housing in contact with a liquid electrolyte. The gas diffuses into the sensor and through the membrane to the working electrode. When the gas reaches the working electrode, an electrochemical reaction occurs; either an oxidation or reduction depending on the type of gas.

What do electrochemical sensors detect?

Electrochemical sensors are used to detect the presence of toxic gases such as H2S, Cl2, and SO2, and variation of oxygen in the air. It consists of two electrodes immersed in common electrolyte medium in the form of gel. The electrolyte is isolated using a membrane. A voltage is applied between the two electrodes.

What are gas sensing electrodes?

Electrochemical gas sensors are gas detectors that measure the concentration of a target gas by oxidizing or reducing the target gas at an electrode and measuring the resulting current.

What is electrochemical sensor?

Electrochemical sensors are devices that give information about the composition of a system in real time by coupling a chemically selective layer (the recognition element) to an electrochemical transducer.

How many types of gas sensors are there?

In this article, we’ll be discussing the four main types of gas detectors: electrochemical sensors, catalytic sensors, infrared sensors and photoionization sensors.

Where are gas sensors used?

They are commonly used to detect toxic or explosive gasses and measure gas concentration. Gas sensors are employed in factories and manufacturing facilities to identify gas leaks, and to detect smoke and carbon monoxide in homes. Gas sensors vary widely in size (portable and fixed), range, and sensing ability.

Where are electrochemical sensors used?

Electrochemical sensors are used for detecting oxygen and toxic gases. More specifically, they measure the concentration of a specific gas within an external circuit. This is done by method of oxidation or reduction reactions. These reactions generate the positive or negative current flow through said external circuit.

Which membrane is used in gas sensing electrode is?

These electrodes have a gas permeable membrane. The inner electrode system is formed by a pH glass electrode and Ag/AgCl reference electrode in the form of a combined pH electrode with a flat glass membrane. From the outer side, the glass membrane is covered by a microporous gas permeable filter.

What are the applications of gas sensor?

Gas sensor (You et al., 2012) converts the components and concentrations of various gases into standard electrical signals by using specific physical and chemical effects. It has been widely used in the detection of noxious and harmful gases and natural gas leakage.

Why do we need gas sensors?

Gas sensor, as one of the most important devices to detect noxious gases, provides a vital way to monitor the concentration and environmental information of gas in order to guarantee the safety of production. Therefore, researches on high sensitivity, high selectivity, and high stability have become hot issues.

What are electrochemical sensors made of?

Electrochemical sensors are made up of three essential components: a receptor that binds the sample, the sample or analyte, and a transducer to convert the reaction into a measurable electrical signal.