What are metal oxide sensors?
MOS sensors detect concentration of various types of gases by measuring the resistance change of the metal oxide due to adsorption of gases. Atmospheric oxygen residing on the MOS surface is reduced by the target gases, allowing more electrons in the conduction band of the metal oxide material.
What is MQ gas sensor?
MQ gas sensors are a family of sensors which are used to detect a wide variety of gases like alcohol, smoke, methane, LPG, hydrogen, NH3, Benzene, Propane etc. These sensors are made up of electrode which is coated with a sensing material, and it is heated to make it more reactive and sensitive.
Is metal oxide a gas?
Metal oxides are crystalline solids that contain a metal cation and an oxide anion. They typically react with water to form bases or with acids to form salts.
How does a metal oxide semiconductor work?
Metal oxide semiconductors represent a class of unique materials due to their electronic charge transport properties when compared to conventional covalent semiconductors such as silicon (Si). Metal oxide semiconductors are valence compounds with a high degree of ionic bonding.
What is name of gas detector?
Pellistor/Catalytic Bead (CB) Industrial Gas Detectors They respond to a full range of flammable gases, including hydrogen, methane, butane, propane, and carbon monoxide. Still, they can be prone to poisoning when exposed to high concentrations of flammable and combustible gases.
What are the specifications of gas sensor?
Sensor Specifications
| Gase Name | Measuring Range | Part Number Sensor Specification |
|---|---|---|
| Carbon Monoxide (CO) | 0 – 300 ppm | 65-2005_2007-CO |
| Hydrogen Sulfide (H2S) | 0 – 100 ppm | 65-2035_2037-H2S |
| Chlorine (Cl2) | 0 – 3.00 ppm / 0-10.0 ppm | 65-2051 |
| Chlorine Dioxide (ClO2) | 0 – 1.00 ppm | 65-2052 |
Where is a NOx sensor located?
The NOx sensor is part of the NOx reduction aftertreatment system used in diesel vehicles with urea based SCR systems. The sensor located upstream of the SCR catalyst directly measures the engine-out NOx gas concentration, which helps determine the optimum amount of urea injection.
What does NOx stand for?
nitrogen oxides
Nitric oxide (NOx) is a chemical compound of oxygen and nitrogen which is formed by these reacting with each other during combustion at high temperatures, mainly the combustion of fuels such as oil, diesel, gas and organic material. NOx is a common name for the nitrogen oxides NO and NO2.
How do MQ sensors work?
MQ2 is a metal oxide semiconductor type gas sensor. Concentrations of gas in the gas is measured using a voltage divider network present in the sensor. This sensor works on 5V DC voltage. It can detect gases in the concentration of range 200 to 10000ppm.
What is smoke and gas sensor?
When there is a fire a lot of gas particles are produced. The sensor detects these and turns the electricity supply on. It can be used to detect the presence of carbon monoxide gas (CO).
What are metal oxide sensors used for?
Metal oxide sensors are primarily gas sensors, and they can sense both oxidizing and reducing gases. This makes them ideal for use in industrial situations where gases used in manufacturing can pose a risk to worker safety.
What is the sensitivity of metal oxide gas sensors?
Many papers about metal oxide gas sensors have been published in recent years [1–20]. As one of the important parameters of gas sensors, sensitivity has been attracting more and more attention and much effort has been made to enhance the sensitivity of gas sensors. There is not a uniform definition for gas sensor sensitivity now.
What are conductometric Semiconducting metal oxide gas sensors?
The conductometric semiconducting metal oxide gas sensors currently constitute one of the most investigated groups of gas sensors.
What is a metal-oxide-semiconductor?
The phrase “metal–oxide–semiconductor” is a reference to the physical structure of certain field-effect transistors, having a metal gate electrode placed on top of an oxide insulator, which in turn is on top of a semiconductor material. Aluminium was once used but now the material is polysilicon.