A gas meter, also called a gas detector, is used in gas measurement technology and measures the concentration of gases in the air. There are both fixed, stationary and battery-powered, portable gas detectors. They contain built-in sensors, which are often based on infrared technology or electrochemical principles. These gas sensors react very sensitively to the gases to be detected and show changes in concentration directly and reliably on a display. The following sensors are installed in gas detectors:
Gas detectors with catalytic sensors are often found in explosimeters that measure combustible and explosive air components. This works by using an isolated sample chamber, catalyst material, and a glowing wire through which to measure the energy that combustible materials give off during combustion. This energy is additionally heated by suitable catalyst material, making it easier to measure. Because of their simple operation and design, catalytic sensors are inexpensive and long-lasting. In addition, they can measure practically anything that burns. However, they require oxygen due to the burning process and do not register toxins in the air.
These sensors are most similar in function to an engine running on gas: A reaction is not triggered until natural gas is supplied. In structure, however, they are more similar to a battery. In a reaction, the room air passes through a permeable membrane to an electrode, where chemical oxidation is triggered. Electrons are produced in the process, but some are also consumed, causing changes in the current flowing through the electrode. These changes are registered and provide information about the condition of the room air.
Infrared sensors function by means of a heat beam sent through the room, which is absorbed to a greater or lesser extent depending on the concentration of certain substances in the air. Some gases absorb radiation even in the visible range, so they show up in certain colors such as violet (iodine), yellow-green (chlorine), etc.
The PID sensors are built into the gas detector and work by UV lamp. The sensor draws in air and feeds it to the measurement chamber where the UV lamp generates photons. This ionizes certain molecules in the gas stream and exposes them to the electric field between the electrode and the counter-electrode. The varying current strength, which is directly proportional to the concentration of ionized molecules in the detector chamber, can then be used to make statements about the gas concentration.
Semiconductor sensors react chemically when in direct contact with certain gases. Usually tin dioxide is used for this purpose, which shows a change in electrical resistance when it comes into contact with a gas. This change can be measured and reveals the concentration of a gas in the ambient air. Accordingly, there are sensors that react according to explosion risk, oxygen deficiency, and toxin content in the air. Some gas meters also have an acoustic warning signal when increased concentrations of toxic or explosive gases or a reduced oxygen concentration in the room air can be measured. They are thus a gas measuring device and gas warning device or gas detector in one. The right sensor should be installed in the gas measuring device depending on the requirements and on how hazardous substances are handled.
The range of gases to be detected is very wide. Typically, oxygen detection is distinguished from the detection of explosive, toxic or flammable gases.
Oxygen (O2): Oxygen is the basis of all our metabolic processes such as respiration. If there is too little oxygen in the air we breathe, there is a risk of suffocation.
Hydrogen (H2): Hydrogen is becoming increasingly important with new energy technologies. However, when combined with oxygen, it can very quickly lead to explosions.
Carbon oxides: Carbon dioxide (CO2) and the even more dangerous carbon monoxide (CO) are mainly produced during combustion processes. In elevated concentrations, both gases can interfere with breathing and can lead to death.
Nitrogen gases: Nitrogen-containing gases, such as NO and NO2, play a major role in exhaust gases or, as amine compounds, are also byproducts of organic reactions.
Sulfur compounds: Sulfur compounds are a common product of decay processes and are found, for example, in wastewater treatment plants and landfills. Typical representatives are H2S and SO2.
Hydrocarbons: Hydrocarbons can occur as organic vapors in the chemical industry or, like methane, also naturally.
Other hazardous gases include chlorine compounds, phosphorus compounds and the extremely toxic HCN.
The occurrence of hazardous gases can play a role in many areas of application. Thus, a measuring device for gases can find useful application in research and development, in industrial areas, with fire departments and rescue services, but also in mining, in tunnels as well as in underground channels.
Whether in fires or in hazardous materials operations - gas detection equipment is an indispensable part of the equipment used by firefighters and other rescue services. The personal protection of firefighters and rescue workers is always in the foreground. Here, the measuring devices provide valuable services and give early warning of the dangers of gases that may occur, for example, in fires or gas leaks.
In numerous industries, employees can come into contact with hazardous gaseous substances, for example in the chemical industry or the oil and gas industry. Extreme temperatures and contact with toxic gases as well as toxic substances are also commonplace in the metal and steel industries. In order to avoid incidents in refineries or chemical plants and to be able to act quickly in dangerous situations, gas detection devices are irreplaceable.
In the municipal supply of water, wastewater or heating gas, the use of gas detection equipment is equally indispensable for the protection of employees. Aggressive vapors and explosive gases can endanger the health of workers in sewage treatment plants, sewer systems or in tanks. For example, many chlorine- and sulfur-based substances are generated in water treatment and must be detected at low concentrations at an early stage to prevent health hazards.
In mining, the use of appropriate gas detection equipment has a long tradition to protect the lives of miners. In this environment, a quick response is required if the air being breathed contains hazardous gases or if oxygen is running low. Gas detectors can also be used in other underground spaces, such as wine cellars or other storage cellars, to ensure the safety of employees working there.
Tailor-made solutions exist for different applications. Generally, a distinction is made based on the local flexibility of the device (portable versus stationary) and the technical flexibility (single or multiple gas devices). The gas detector types available at MedSolut.com are presented in detail below.
Single-gas monitors are designed to very specifically and sensitively measure the concentration of a particular gas. The instruments then contain a special sensor that responds only to the gas being detected. Typical applications are oxygen gas monitors, CO2 monitors or single gas monitors for the detection of carbon monoxide.
Multi-gas detectors are typically more expensive than single-gas detectors because they are designed to detect multiple gases simultaneously. Therefore, the sensor system is also correspondingly more complex in design. The Dräger gas detector X-am 5600, for example, can reliably detect 1 to 6 toxic, flammable or explosive gases and is especially suited for industrial use under the corresponding harsh environmental conditions.
Stationary instruments are permanently installed at the appropriate locations and are used for continuous monitoring of an area. They can be used as single gas detectors as well as multi-gas detectors. Typical applications are the monitoring of entire industrial plants or basement rooms.
Portable gas detectors are used when they are used as part of personal protective equipment or need to be very flexible in terms of location. The devices are light and handy and warn the employee of dangerous situations at an early stage. Mobile gas detection devices such as the Dräger gas detector X-am 5000 are used, for example, during firefighting operations or in mining.
The range at MedSolut.com includes mainly mobile gas detection devices exclusively from brand manufacturers, from single gas detection devices to complex multi-gas detection devices.
Dräger X-am(R) 5000: This is a measuring device for 1 to 5 gases. It is handy and reliably detects combustible and toxic gases as well as oxygen.
Dräger X-am(R) 2500 FlexThis device has been specially developed for use in potentially explosive atmospheres and is therefore particularly safe. It detects 1 to 4 different gas types.
Dräger X-am(R) 5600: This is a particularly ergonomic, robust and waterproof measuring device that can detect up to 6 gases.
Dräger X-dock(R): This series allows you to control all existing portable gas detection devices with one station. With automatic gassing test and optimized calibration, your portable instruments are always ready for use.
To ensure that measuring instruments for gases also function faultlessly and display the correct measured values, they must be regularly maintained, calibrated and, if necessary, readjusted. Details are regulated in the two standards DIN EN 60079-29-2 (explosive gases/vapors and oxygen) and DIN EN 45544-4 (toxic gases/vapors). The two leaflets T021 and T023 describe the procedure in detail. The standards stipulate that portable gas detectors must be exposed to the gas to be tested before each shift to ensure proper functioning. In addition, instruments for combustible gases must be calibrated every 4 months and instruments for oxygen or toxic gases must be calibrated every 6 months . MedSolut.com's team of experts will be happy to assist you in performing the appropriate calibrations and adjustments.
You want to increase the safety of your laboratory or your equipment and have decided to buy a gas meter or other measuring devices (e.g. for measuring electricity)? Feel free to contact us so that our expert consultants can provide you with competent and personal advice and help you find the optimal device for your application. You can reach us by phone at +49 30 2096579 00 or via e-mail at info@medsolut.com.