There are several types of methane detectors available. Laser, Infrared, Electrochemical, and Catalytic are a few. These technologies have different advantages and disadvantages. This article will go over some of the differences between these types. This will help you choose the best type of methane detector for your needs.
Laser type methane sensors
Laser type methane sensor use a laser and molecular interaction principle to detect the presence of methane gas. These sensors have response times under a microsecond. These are faster than existing products that require 6 to 8 seconds. This makes them an effective tool for monitoring gas leakages in the environment.
Compared to solid-state sensors, laser sensors have lower power consumption. This makes them ideal for portable instruments. They are also intrinsically safe, shock-proof, dust-proof, and moisture-proof. Another advantage of laser type methane sensors is their low sensitivity and long service life.
Unlike infrared methane sensors, laser type sensors do not require catalytic gas. They can be used even in atmospheres where there is no oxygen. Laser type methane sensors can also display ambient temperature.
Infrared type methane sensors
Two types of methane sensors are available: the infrared type and the laser type. The former uses a laser light source to produce IR radiation, while the latter uses infrared radiation from the heating of a special ligament. Despite the similarities between the two technologies, infrared sensors exhibit a lower response speed and require long integration times. On the other hand, laser sensors are more stable than infrared sensors.
The sensitivity of a silicon-on-nitride slot waveguide sensor can be derived from equation (1)32-34, where S is the sensitivity of the sensor. The sensitivity of this type of sensor depends on the gas absorption losses and the length of the waveguide device.
The difference between infrared sensors and catalytic sensors lies in their wavelengths. An infrared sensor uses different wavelengths to measure gas concentration, and a catalytic sensor utilizes the energy released during combustion to change resistance. This change is measured as the percentage LEL. A catalytic sensor must have enough oxygen to work correctly, as high concentrations of toxic gases can affect the performance of the sensor.
Electrochemical type methane sensors
Electrochemical type methane sensors measure methane concentrations. The process of methane oxidation generates a current, which is indicative of the presence of methane in the sample. This current signal can be measured by an ammeter or other suitable current-measuring device. The typical signal is in the range of microamperes.
A typical electrochemical sensor has a working electrode, a counter electrode, and a reference electrode. These components are contained in a sensor housing, which is immersed in a liquid electrolyte. The working electrode is located on the inner face of a Teflon membrane, which is porous to the gas but impermeable to the electrolyte.
Electrochemical sensors require a high temperature to function, which limits their usefulness in applications that require low concentrations. They also require a high power supply, which makes them less useful for portable instruments. Laser detectors, on the other hand, can operate at much lower temperatures and require less power. In addition, laser detectors are dust, shock, and moisture proof. Laser type methane sensors have a long service life and a wide measurement range.
Catalytic type methane sensors
A methane sensor, or catalytic type methane sensor, measures the concentration of methane in an atmosphere. Its output voltage is measured with a voltmeter and can be calibrated to detect a concentration of 2.5% CH4. The output signal of this type of sensor increases with the methane concentration in the atmosphere. This type of sensor requires a high amount of energy to operate.
Catalytic type methane sensors are based on the principle of chemical reaction between methane and oxygen in the air. The gas undergoes an oxidation reaction and generates heat as a result. This reaction happens on the surface of the catalyst, which is embedded within a heating element. When methane is present in the air, the resistance of the pellet increases, resulting in a signal. This sensor is effective for detecting methane even in the presence of low oxygen levels and in mixed gas.
Conclusion
The catalytic type methane sensor is a popular choice for analytical detection of flammable gases. Its sensitivity can reach 15 mV/ CH4 catalytic sensors are made of anodic alumina support and are useful for methane detection. These sensors have been studied using and X-ray diffraction. The sensitivity response of this type of sensor varies with the oxides content in the catalyst.
