How Many Types of Gas Detectors Are There?

Gas detection is the process of identifying and monitoring potentially dangerous levels of gases, using gas detection monitoring systems.

In Australia, gas detectors are used in a broad scope of practices and residential properties, to ensure the safety of those living and working in the space, and the general public. Gas detectors are relied upon to provide ample warning when in the presence of dangerous gases. The specialist devices used for gas detection can come in various forms to meet the unique demands of different gas monitoring applications.?

How Many Types of Gas Detectors Are There??

Regarding how many types of gas detectors are there; there are approximately eight different gas sensor technologies used to identify and monitor gas levels. Gas detectors can be characterized according to the operation mechanism, as various industrial applications generally call for unique gas detection safety systems. In this article, we’ll be discussing the four main types of gas detectors: electrochemical sensors, catalytic sensors, infrared sensors and photoionization sensors.

Essentially, these various types of gas detectors fall into two categories: portable and fixed. Portable gas detectors are typically handheld or worn on safety equipment and used to monitor personnel’s atmosphere. Portable gas detectors often emit warnings with audible and visual signals when dangerous levels of gases are detected.

Fixed gas detectors are monitoring systems that are generally mounted near the process area of a plant or control room, or in an area that requires protection, such as underground car parks. Fixed gas detectors will typically make both visual and audible warnings when hazardous gases are detected and monitor the levels of more than one specific gas.?

What Are the Types of Gas Detectors?

Now that we’ve explained how many types of gas detectors are there, here’s a run-down of the four main types of gas detector technologies utilised to detect harmful gases: electrochemical, catalytic bead, infrared and photoionization sensors. When making your gas detection selection within those types of gas detectors, it’s also vital to consider single gas detectors and multi-gas detectors.

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1. Electrochemical Gas Sensors

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Electrochemical gas detectors measure a specific gas’s concentration by oxidising or reducing the gas to an electrode, generating a positive or negative current flow. Electrochemical gas sensors are typically used to measure the concentration of a target gas within an external circuit. When considering how many types of gas detectors are there, electrochemical and catalytic combustible gas technologies are the most commonly used and understood.?

2. Catalytic Bead Sensors?

Catalytic gas detectors are typically used to measure combustible gases that come with an explosion hazard when concentrations are between the lower explosion limit (LEL) and the upper explosion limit (UEL). Catalytic gas detectors are based upon the principle that when gas oxidises, it produces heat, and the sensor will convert the temperature change via a Wheatstone bridge-type circuit.?

One of the beads of the catalytic sensor consists of a special catalyst which promotes oxidation, and the other is treated to inhibit oxidation. Current passes through the coils to that they reach oxidation temperature (500 degrees Celsius), increasing the platinum coil’s resistance, leading to an imbalance of the bridge. The resistance change is directly related to the gas concentration in the surrounding atmosphere, displaying the gas reading on the meter or similar indicating device.?

3. Infrared Gas Sensors?

An alternative to combustible gas measurements, infrared sensors are used when there is no oxygen present, or in situations where you measure high carbon dioxide concentrations. Working on the principle of light absorption, the change in the absorbed light intensity is measured relative to the intensity of light at a reference wavelength. The infrared sensor computes the difference in absorbed light and reports the gas concentration from the absorption.?

4. Photoionization Gas Sensors?

A photoionization gas detector uses an ultraviolet light source to ionise gases to positive and negative ions that can easily be identified with a detector. Ionisation occurs when a molecule absorbs the light energy of a gas. The photoionization detects or measures the charge of ionised gases, with the charge being a function of the concentration of volatile organic compounds (VOCs) found in the atmosphere.?

Single & Multiple Gas Detectors

When deciding what type of gas detector you need, it’s important to consider both single gas detectors and multi gas detectors. While many spaces require the careful monitoring of a single target gas, restricted areas and confined spaces often need to be monitored for oxygen enrichment or deficiency, the presence of one or two toxic gases, and combustible gases. The type of gas detector that you invest in should be well suited to your application and your property’s specific needs. You can shop the full range of Newcastle Safety Servicing’s single gas detector and multi gas detector devices online.?

What Can A Typical Multi Gas Detector Monitor?

Multi-gas detectors are generally equipped to monitor O2 levels while detecting the presence of combustible and toxic gases in the environment. A wide variety of multi-gas detectors will detect several different gases, depending on where they are required and the specific gases that need to be monitored. In Australia, organizations can select a multi-gas detector that will meet the unique demands of their operations.

However, in the case of “what can a typical multi gas detector monitor?”, common substances monitored include hydrogen sulphide, carbon monoxide, oxygen and combustible gases (LEL). Multi-gas detectors may detect carbon dioxide, sulphur dioxide, ammonia, chlorine, VOCs, and many other gases, depending on the sensor configuration.

Types of Industrial Gas Detectors: Choosing the Right One

Safety is always a priority in any work environment, but industrial facilities require a special level of care and consideration. For example, industrial plants need tools for monitoring gas leaks and other potential hazards. Without the right precautions in place, employees can fall victim to avoidable accidents.