Gas detection is the process of identifying and monitoring potentially dangerous levels of gases, using gas detection monitoring systems.
In China, 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.
So, how many types of gas detectors are there?
China’s leading team of gas detection specialists, JXCT are here to bread provide an informative guide on how many types of gas detector are there, the different types of gas detectors and why they are used in various situations.
On top of delivering exceptional gas calibration services and repairs, JXCT also provide a number of gas detection devices from internationally recognised manufacturers. When it comes to gas detection, we’re your experts.
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 characterised 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 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 Detector?
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.
1. Electrochemical Gas Sensors
Electrochemical detector 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 detector are there, electrochemical and catalytic combustible gas technologies are the most commonly used and understood.
2. Catalytic Bead Sensors
Catalytic detector 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 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 (PID) 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.
What Can A Typical Multi Gas Detector Monitor?
Multi-gas detector 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 detector will detect several different gases, depending on where they are required and the specific gases that need to be monitored. In Australia, organisations 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.
As well as supplying leading gas monitoring equipment, JXCT also provide exceptional gas detector calibration, servicing and gas detector repairs across NSW. We calibrate, test, certify and inspect all types of detectors, calibration equipment and gas monitoring gear. Our online range of gas detection equipment includes multi gas mixture calibration gas, single gas mixture calibration gas, portable multi gas detector and single gas detector devices. Our knowledgeable and friendly technicians can help you with every aspect of your gas detection enquiry – from calibrating your equipment to providing friendly, professional, expert advice on purchasing the right type of gas detector. Get in touch with us today on WhatsApp +15588302704 to learn more.
