What is a gas detector?
Detectors used to detect different gases are often classified into two groups.Methane gas detectors Combustible Flammable gas detectors and Toxic gas detectors, each of which is available in different brands depending on the type of gas. (Oxygen gas detectors are often not classified in these two categories.) In some brands Gas detectors There are several different types of gas detected. Most of these detectors consist of two parts: Transmitter and Sensor. Transmitters are sometimes equipped with control and display capabilities. It should be noted that most sensors have an expiration date and should be calibrated according to instructions and by trained people. Some manufacturers of gas detectors also produce panels for their gas detectors for their detectors, but most of the gas detectors are connected to the panels with a module.
Types of sensors :
Types of gas detector outputs:
4-20 mA two-wire and three-wire *
Relay output (three alarm relays, pre-alarm and fault) *
to recognizeGas leak And warning before a fire occurs, especially in places where flammable gases (LPG, CNG) are used.DetectorsEthylene oxide gas Is used. Some of them are based on the smell of gas and are installed on the wall or ceiling. They are used in apartments, hotels and industrial centers. Some types of this detectorEthylene oxide gasThey are able to command a valve and close the gas path if a gas leak is detected.
tipIn more advanced detectors, changes in gas density are converted by the converter to a current of 4 to 20 mA and sent to the central control panel with a three-wire cable for measurement and control. There are also systems with special detectors and central panels that detect the amount of carbon monoxide (CO) in the environment and if the concentration is low, oneair conditioning system Launches and warns if its concentration is high in ambient air. These detectors are used in public parking lots and in underground tunnels and places where fuel Carbon monoxide They use it like coal or oil. Sometimes gas detectors are attached to their own panel.
Brief about gas detectors:
Ethylene oxide gas detectorsAre equipment designed to identify and Toxic gas monitoring , Flammable and explosive as well as oxidizing gases [generally dangerous gases that are toxic, explosive or combustible] are used. These detectors are equipped with alarm systems [sirens and flashers], some of which are portable by users, using a vibrator [vibrator] for notification. These categories [either fixed or portable and portable] are each used for appropriate uses, most of which are used to detect only one type of a gas (by measuring the concentration of that gas). Of course, some of these devices have multiple sensors, capable of detecting multiple gases simultaneously.
Detectors that are mostly used to detect toxic gas concentrations [using electrochemical (EC) sensors and metal oxide semiconductors]. Some are also used to detect combustible gases [as smoke detectors,Infrared sensors (Infrared or IR) and catalytic (CATALYTIC)] are used. These detectors are also used to detect hypoxia.
The company is currently supplying more than 200 different types of gases [hydrocarbons, non-hydrocarbons, alkanes, alkalis, petroleum products, carbon monoxide, diesel, etc.], some of which are hybrid [multi-gaseous] Gases are detected simultaneously in several ways] and.. In this regard, it should be noted that each of theseChlorine gas detector [Like some other fire alarm equipment] has a variety of codes to order, so that for a specific gas with a specific brand [in terms of standard type, approval, price and برخوردار has a great variety with a general title (non-specialized And market) you can provide or distribute a piece of equipment with a brand and production of a particular company, but maybe up to twice the different price, so it is better for companies to ask the appropriate equipment and technical specifications before inquiring about the price [ Through experienced and technical consultants] ensure.
Gas detectors are devices that are used to detect and monitor toxic, flammable and explosive gases, oxidizing gases and, in general, hazardous gases. Gas meters are equipped with visual and audible warning systems (audio) and in some models (portable) vibrators or vibrators are used to alert users.
Sensors of gas meters are usually classified according to the technology used to detect gases:
1) Gas sensors with infrared technology: (IR) (for detection of hydrocarbon vapors)
These detectors are mostly used for propylene, ethylene, ethanol, ethylene oxide, methyl bromide, methane, ethane, propane, butane, hexane and gases.
2) Electrochemical gas sensors:
Toxic gas electrochemical sensors (CO, Chlorine, NOx, H 2 ) are used, which are generally very sensitive.
3) Catalytic sensors: (For the detection of hydrocarbons)
These detectors are also used for ammonia (NH3) (LPG) gases, gasoline vapors, hydrogen and alkanes (methane, ethane, propane, butane, pentane, etc.), explosives, etc. However, they must be delivered on time. Its use was noticed.
4) Measurement using semiconductors (metal oxide semiconductor sensors are commonly used to detect monoxide)
1- Gas odor detection
2- Detection of gas density changes (from 4 to 20 mA, via three-wire cable… message to the control panel)
3- Measuring the amount of carbon monoxide [CO], (for a small amount: launching the ventilation system, for large amounts: a warning sign, more in parking lots and underground tunnels)
How gas detector works:
A specially molten platinum filament is placed inside the chamber and ignites as soon as it comes in contact with the gas. Changes in the light intensity of this platinum filament affect a photoelectric cell and trigger various devices [sirens and…] by means of the corresponding circuits.Gas detectors They are generally battery operated and portable.
+ Detection at a level much lower than the LEL value [Lower Explosive Limit] or detection around LEL 20-20.
Differences between gases and vapors:
gasesIn the gaseous state, they are higher than the critical temperature (ie, they do not liquefy by pressure).
SteamIn the gaseous state, they are below the critical temperature (due to pressure, they become liquid).
Gas detectors are the most diverse among other detectors such as detector type, detection for gas type, detection for gas odor or combustion or explosion, construction or industrial application, fixed or portable installation and. . . . In this way, we are faced with a wide market both in type and price, so that its price range, even in consumption for a demand and a type of gas, we are faced with a multitude of market prices [except being original or not] and Of course, in Iran, only sales are discussed and its technical discussion is often ignored. For example, for Spectrex and PB type, we are faced with dozens of different models and prices, each of which, contrary to the same name, has different functions.
Rose Calibration Company in Melbourne, Australia with over ten years of experience provides all calibration, maintenance, and repair services throughout Australia. If you live in Sydney, Melbourne, Adelaide, Perth, Geelong, and Brisbane, you can receive your quote in less than two hours by fill-up the form via the “Booking” link.