Toxic Gases That Can Be Detected By Gas Sensors

by Charlie G. Avid oil blogger

There are a range of different gas sensors that can detect certain gases such as carbon monoxide, hydrogen sulphide, carbon dioxide or sulphur dioxide among others. For people whom work in an environment which contains hazardous gases that could be harmful to your health, choosing the right type of gas detector is a very important decision.

Gas detectors come in all shapes and sizes, with a variety of colours and sensor configurations. Common gas sensors include Electrochemical Sensors, Infrared Sensors & Metal Oxide Sensors (MOS).

1. Electrochemical sensors are most frequently used in the detection of toxic gases such as carbon monoxide, nitrogen oxide and hydrogen sulphide. They function by electrode signals which are notified when a gas is detected. Generally, these types of detectors are extremely sensitive and issue warning signals via electrical currents. Some main features of the electrochemical sensors are:

- Very low power usage
- Good responses to various gas concentrations
- Less expensive than other gas detection technologies
- Excellent reliability and accuracy

2. Metal Oxide Sensors are also used for detecting toxic gases (most commonly carbon monoxide) and work through a gas sensitive film that is composed of tin oxides. The sensitive film reacts with gases, thus triggering the device when the levels of toxicity are present. Generally, metal oxide sensors are considered to be quite efficient due their ability to operate in low-humidity ranges. In addition, they are able to detect a range of different gases, including combustible gases. Some main features of the metal oxide sensors are:

- High sensitivity
- Wide detection range
- Long life expectancy
- High resistance to shocks and vibrations

3. Infrared Sensors are designed for sensing CO2 and various hydrocarbon gases. Many of the hydrocarbons that are found today are mostly detectable with an infrared sensor. As infrared gas detection is based upon the ability of gases to absorb IR radiation, gases such as hydrogen and carbon monoxide cannot be detected using infrared detectors, because they do not absorb IR radiation. Some main features of the infrared sensors are:

- Does not have to directly interact with the gas to be detected
- Simplest way to convert light energy into an electrical signal
- Responds to all wavelengths
- Highly accurate