
A gas detector is a device used to detect gases in the air. It is commonly used in industrial settings, mining, the oil and gas industry, as well as in residential homes to detect potentially hazardous gas leaks. In this article, we will explain in detail the different types of gas detectors and how they work.
Gas detectors are capable of detecting and measuring various types of gases in the air. Most gas detectors are specialized for specific types of gases, such as carbon monoxide, methane, propane, or hydrogen. However, some detectors are capable of detecting multiple types of gases simultaneously.
Types of Gas Detectors
There are three main types of gas detectors: electrochemical, catalytic, and infrared detectors.
Electrochemical Detectors
Electrochemical gas detectors work by oxidizing the gas at an electrode. When the gas is oxidized, it produces a current that is proportional to the concentration of the gas. This current is measured by a microprocessor in the detector and converted into a concentration unit.
Electrochemical detectors are very sensitive and can detect very low concentrations of gases. However, they are prone to false alarms and can be affected by other gases or chemicals.
Catalytic Detectors
Catalytic gas detectors work by burning the gas on a catalyst. When the gas is burned, heat is released, which is measured by a thermistor in the detector. The temperature increase is proportional to the concentration of the gas.
Catalytic detectors are very sensitive and can detect a variety of gases. However, they are prone to false alarms and can be affected by other chemicals.
Infrared Detectors
Infrared detectors work by measuring the absorption of infrared light by the gas. Each gas has a unique absorption pattern in the infrared spectrum that distinguishes it from other gases. The detector sends infrared light through the gas and measures the absorption. The measured absorption is proportional to the concentration of the gas.
Infrared detectors are very specific and can detect certain gases very accurately. However, they are more expensive than electrochemical and catalytic detectors and can be affected by other infrared-absorbing gases.
How a Gas Detector Works
Regardless of the type of gas detector, there are certain steps the device goes through to detect a gas leak.
Sampling
First, a sample of the air that is to be tested for the presence of gases must be taken. This is done through an inlet system placed near the potential gas source. The air sample is then drawn through the gas detector to measure the gas concentration.
Gas Detection
Once the air sample is introduced into the gas detector, the device begins gas detection. Depending on the type of detector, this can be done through an electrochemical reaction, catalytic combustion, or infrared absorption.
Signal Processing
After the gas is detected, the signal from the detector is sent to a microprocessor, which processes the signal and converts it into a concentration unit. The concentration is then displayed on the gas detector's display.
Alarm
If the measured gas concentration exceeds a certain threshold, the detector triggers an alarm. Most gas detectors have an acoustic alarm that emits a loud sound to indicate the presence of gas. Some detectors also have visual alarms, such as flashing lights or a changing display.
Applications of Gas Detectors
Gas detectors have many applications in various industries and environments. Here are some examples:
Industrial Applications
In industry, gas detectors are frequently used to ensure worker safety. Particularly in the chemical industry, oil and gas industry, and in the production of industrial gases, gas detectors are used to monitor potentially hazardous gases such as carbon monoxide, hydrogen sulfide, or methane.
Mining
In mines, gas detectors are used to monitor the concentration of methane and carbon monoxide. Methane is a flammable gas and can cause explosions at high concentrations. Carbon monoxide is a colorless, odorless gas that can be fatal at high concentrations.
Residential Applications
Gas detectors are also used in residential homes to detect carbon monoxide leaks. Carbon monoxide is an odorless, colorless gas that can be produced by combustion sources such as furnaces, heaters, and fireplaces. Inhaling it in high concentrations can be fatal.
Conclusion
Gas detectors are an important part of safety in various industries and environments. There are different types of gas detectors that are specialized for different types of gases. The operation of a gas detector is based on sampling, gas detection, signal processing, and alarm. Gas detectors are essential in many applications to ensure the health and safety of workers and the public.
Gas-Pro TK dual range portable monitor measures the concentration of flammable gas in inerted tanks. Available for methane, butane and propane, Gas-Pro TK uses a dual IR sensor – the best technology for this specialist environment, which means Gas-Pro TK dual IR:
- Isn’t inhibited by high hydrocarbon concentrations unlike catalytic bead sensor;
- measures gas in high %vol as well as %LEL concentration, which single IR sensors can’t;
- auto-ranges switch between %vol and %LEL measurement, so always operating to the correct parameter.
- low enough to load and store fuel safely;
- high enough for safe tank entry.
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Gas-Pro PID utilises the Photo Ionization Detection technology to allow you to detect hundreds of Volatile Organic Compounds (VOCs). If you are working in an environment that is high in levels of solvents, glues, paints and general VOCs, the Gas-Pro PID will monitor your safety. With its dual-coloured display, the monitor will alert the user with its 95db audible alarm and its dual-coloured visual alarm bars.
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The Gas-Pro IR is ideal for the oil and gas industry. This personal multigas monitor can detect methane, pentane or propane using infrared (IR) sensor technology. The Gas-Pro IR is ideal for detecting potentially explosive gases where traditional, ”pellistor”, catalytic sensors will struggle – especially in a low oxygen environment.
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Portable 4 gas detector provides effective protection against 4 common gas hazards: carbon monoxide, hydrogen sulphide, flammable gases and oxygen depletion. Now with improved detection of pentane, hexane and other long chain hydrocarbons. Offering you compliance, robustness and low cost of ownership in a simple to use solution. T4 contains a wide range of powerful features to make everyday use easier and safer.
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The Tetra:3 multigas monitor is a compact, robust and easy-to-use diffusion based detector. Single button operation, small size and clear top-mounted display make it a favourite in the market amongst those working in demanding industrial environments, such as those in the water, telecoms, food, brewing or hydrocarbons sectors.
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The Gasman full function personal single gas monitor is compact and lightweight yet is fully ruggedised for the toughest of industrial environments. Featuring simple single button operation, it has a large easy-to-read display of gas concentration, and audible, visual and vibrating alarms.
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Clip Single Gas Detector (SGD) is designed for use in hazardous areas and offers reliable and durable fixed life span monitoring in a compact, lightweight and maintenance-free package. Clip SGD has a 2-year life and is available for hydrogen sulphide (H2S), carbon monoxide (CO) or oxygen (O2). Clip SGD is designed to withstand the harshest industrial working conditions and delivers industry leading alarm time, changeable alarm levels and event logging as well as user-friendly bump test and calibration solutions.
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Detective+ is a multi-gas temporary area monitor for use in turnaround/shutdown procedures, hot work maintenance, confined space entry work and many other utility, construction and oil and gas industry applications. Go solo or link together using Detective Net to form a perimeter, Detective+ gives a loud and clear alarm providing effective warning of gas hazards. The rugged, water and impact resistant design make Detective+ the ideal choice for your transportable gas detection needs.
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Detective Wireless is a module that can replace interconnecting cables for Detective+. Detective Wireless will transmit gas alert signals and other alarms wirelessly between Detective units using a 433MHz signal up to 100 metres in distance.
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The LaserMethane mini (LMm) is an innovative long-range portable detector which allows methane gas to be detected at distances of up to 100m. This enables easy access to hard-to-reach locations, such as elevated piping or locked premises, and helps keep the operator away from potential leak sources.
Latest development – LMm is now available with Bluetooth connectivity.
Previously only available in a ‘safe-area’ version, Bluetooth is now an available option for the ATEX approved LMm. This allows connection to an Android device using the GasViewer app delivering data storage functionality. This means that important survey data including gas level, time, date and location can be combined, saved or emailed to a central point.
Product not available anymore. Alternative: Laser Methane Smart
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With regulations driving tighter calibration routines and the requirement for daily bump testing, there is a real need for test gas. Gas detectors play a key part for people and plant safety so equipment cannot afford to be out of service.
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