Hydrogen sensing

Hydrogen gas (H2) is a colorless, odorless, combustible gas. It has many industrial applications, mostly in the processing of fossil fuels, metal refining, and 

Dissociated hydrogen causes a change in the channel and conductance, creating a measurable signal. This makes sensors based on an integrated semiconductor device extremely sensitive to a broad, dynamic range of hydrogen concentrations. 

1 AIGaN/GaN HEMT Schottky diode-based hydrogen sensor 

Hydrogen sensors are particularly interesting for the emerging fuel cell vehicle market. There are also applications for detection of combustion gases for fuel leak detection in spacecraft, automobiles and aircraft, fire detectors, exhaust diagnosis and emissions from industrial processes (Baranzahi 

6 (a) Cross-sectional schematic of a completed Schottky diode on an AIGaN/GaN HEMT layer structure (b) plan-view photograph. 

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Many physical principles can be employed by different sensor vendors to obtain the same measurement. For example, in 1995, 49 vendors were listed for hydrogen sensing (2). Represented among the sensor systems are mass spectrometers, gas chromatographs, electrochemical cells, thermal... 

Traditional Approaches to Hydrogen Sensing 15.2.2.1 Thermal Conductivity... 

Mass spectrometry is another widely used technology for hydrogen sensing in the industry. Process mass spectrometers such as gas chromatographs must be safety certified to operate in the plant environment. Mass spectrometers require special air-conditioned... 

Mechanism of hydrogen sensing with palladium thin films. 

Several hydrogen sensing technologies and detection schemes were discussed in this chapter. The success of each technology is determined by its performance in the target application domain. 

Samuel, J.I., Sasikaran, Kv Kourosh, K.-Z., Adrian, T. and Wojtek, W., A layered surface acoustic Wave ZnO/LiTaOj structure with a WOs selective layer for hydrogen sensing, Sensor Letters, 1, 33, 2003. 

Xu, T., Zach, M.P., Xiao, Z.L., Rosenmann, D., Welp, U., Kwok, W.K. and Crabtree, G.W., Self-assembled monolayer-enhanced hydrogen sensing with ultra thin palladium films, Applied Physics Letters, 86, 203104, 2005. 

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