In this research, we used the surface acoustic wave (SAW) sensor to detect chemical compounds such as ammonia, methane, and ammonia-methane mixture gases. Very low concentration of ammonia (~250 ppb) and methane (~9 ppm) can be detected by our SAW devices. And we used mesoporous carbon hollow nanosphere in Poly-N-vinylpyrrolidone (PNVP) film to increase the sensitivity to ammonia from 6.91 to 1...

Physical Sciences Inc. (PSI) has developed an imaging sensor for remote detection of natural gas (methane) leaks. The sensor is comprised of an IR focal plane array-based camera which views the far field through a rapidly tunable FabryPerot interferometer. The interferometer functions as a wavelength-variable bandpass filter which selects the wavelength illuminating the focal plane array. The s...

The oxidative coupling of methane (OCM) was investigated using a catalyst with core@shell structure or physical mixture comprised MgO and SiC Fe 3 O 4 , which thermally activated via conventional resistive heating microwave heating.

A novel low-cost sensor system for the measurement of low angular or linear speed is presented. The sensing element consists of a noncontact resistive potentiometer. The applied sliding electrode does not make mechanical contact with the resistive layer. The processing circuit consists of a very linear oscillator which converts the position quantity to a period-modulated signal. This signal can...

Resistive oxygen sensors are an inexpensive alternative to the classical potentiometric zirconia oxygen sensor, especially for use in harsh environments and at temperatures of several hundred °C or even higher. This device-oriented paper gives a historical overview on the development of these sensor materials. It focuses especially on approaches to obtain a temperature independent behavior. It ...

By means of secondary biogenic gas generation, Microbially Enhance Coalbed Methane (MECoM) technology is used to improve methane content in coalbed. Methanogen consortium metabolism process is the basic avenue for MECoM to yield methane with some organic compounds in coal. Detailed information about the metabolism process is needed in studying the microbial consortium mechanism. Traditional gas...

In this paper a nanocrystalline (nc) zinc oxide based hybrid gas sensor with signal conditioning ASIC has been reported for sensing and transmitting the information about methane concentration from the underground coalmine environment. A low power, low temperature nc zinc oxide MEMS based gas sensor has been designed, fabricated and tested for the purpose with a power consumption of ~70mW and s...

With one operational amplifier (op-amp) in negative feedback, the traditional zero potential circuit could access one element in the two-dimensional (2-D) resistive sensor array with the shared row-column fashion but it suffered from the crosstalk problem for the non-scanned elements' bypass currents, which were injected into array's non-scanned electrodes from zero potential. Firstly, for supp...