Background: 

An electrochemical gas sensor is a gas detector used to measure the concentration of a target gas by oxidizing or reducing the gas at an electrode and measuring the resulting electric current. The first electrochemical sensors were developed in the 1950s to monitor oxygen. By the mid-1980s, tiny electrochemical sensors for detecting a variety of toxic gases were available. Currently, a wide range of electrochemical sensors are used in various applications.

Electrochemical gas sensor

The sensor consists of two or three electrodes in contact with the electrolyte. The electrodes are made of porous hydrophobic membranes immobilized with high surface area noble metals. The most commonly used electrolytes are mineral acids. The electrodes are usually located in a plastic housing consisting of air inlet holes and electrical contacts.

In some cases, scrubber filters are also fixed in front of the sensor to filter unwanted gases. The most commonly used filter medium is activated carbon.

Working Standards

Electrochemical sensors work by diffusing a target gas into the sensor, which generates an electrical signal proportional to the gas concentration.

Gas in contact with the sensor passes through a small capillary-type opening and diffuses through the hydrophobic barrier to the electrode surface. As a result, a sufficient amount of gas is allowed to react at the sensing electrodes to generate a sufficient electrical signal. The diffused gas is in turn oxidized or reduced at the sensing electrode.
With the help of a resistor connected between the electrodes, the current flowing between the anode and cathode can be measured to determine the gas concentration.

Application

Electrochemical sensors use minimal power to operate. In fact, the sensor has the lowest power consumption of any gas monitoring sensor. Therefore, electrochemical sensors are widely used in confined Spaces. Such as monitoring indoor air quality and gas leakage, as well as a portable instrument composed of multiple sensors.

JXCT's analog /TTL electrochemical gas sensor module is a self-developed intelligent gas detection module. It has the characteristics of small volume, easy to carry, high precision and low loss. Factory calibrated and ready for use.