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Substance-Specific Electrochemical Toxic Gas Sensor

Last updated: November 25, 2018

What Does Substance-Specific Electrochemical Toxic Gas Sensor Mean?

A substance-specific electrochemical toxic gas sensor is a type of sensor that can detect and measure the presence of specific toxic gases in a given environment.

Approximately 30 different chemicals can be detected using this type of sensor, and it provides highly accurate readings for the specific substance it is built to detect. Confined space monitoring is a common use-case for electrochemical sensors.

Safeopedia Explains Substance-Specific Electrochemical Toxic Gas Sensor

Substance-specific gas sensors operate by reading the value of an electrical current that is created when the gas monitor is exposed to the chemical of interest. This substance-specific reaction eliminates or reduces the risk of obtaining a false positive due to the sensor detecting other chemicals. These sensors are used in portable gas monitors to ensure that an area is safe for workers to enter or stay in, to look for potential leakages of toxic gas, and to monitor potential worker exposure to a substance to ensure the exposure level does not exceed a given statutory or work policy limit. They may also be used in stationary detection sensors that continuously monitor the air and alarm when the presence of a chemical is detected above a certain acceptable threshold.

Substance-specific electrochemical toxic gas sensors are a common tool for workplace exposure monitoring and hazard identification. Electrochemical gas monitors come equipped with specific chemical cartridges that undergo an oxidation reaction with the chemical that the sensor is being used to detect. The greater the presence of the targeted chemical, the more significant the chemical reaction will be.

The electrochemical reaction generates an electrical current that is monitored by the sensor. The amount of current generated increases linearly according to the amount of reaction taking place, which means that it can be correlated with the amount of chemical being detected. The gas monitor is thus able to translate the amount of change in current that is read by the sensor into an accurate measurement of the amount of chemical in an environment.

There are some drawbacks to the use of electrochemical gas sensors. Because they rely on a chemical reaction for their measurements, the amount of chemical in the cartridge will decrease at a rate commensurate with the amount of chemical they detect. This requires that the gas monitor be regularly inspected to ensure that sufficient quantities of testing chemical are left in the cartridge, and it may make them less-than-ideal for stationary sensors used in an area in which there is a constant presence of the chemical to detect.

Electrochemical sensors are also not suitable for work in low-temperature or high-pressure environments, as these can alter the manner in which the chemicals involved react with each other. Finally, while monitoring systems are built to prevent unwanted interactions, vulnerabilities to reaction with specific undesired chemicals may still need to be accounted for in some instances.


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