It is known that catalytic sensors have different sensitivities to different combustible gases. Usually gas analyzers are calibrated by methane and not suitable for measuring other flammable gases. Correction is needed to get real concentration of other gases. In this paper it is shown that sensor sensitivity to one particular gas alters with sensor temperature and each gas has its own rate of ...

David Arellano has been working in the Embedded Systems lab in the Electrical Engineering Department since Spring 2014 and plans on attending graduate school after receiving a bachelors degree. He also plans to stay involved with the research community after graduation. With a passion for travel, he hopes to see as much of the world as possible. Free time is spent studying theology, philosophy,...

A direct resistance-to-digital converter (RDC) that is suitable for differential resistive sensors is proposed and analyzed in this paper. The RDC presented here provides a digital output that is linearly proportional to the parameter being sensed by a differential resistive sensor possessing either linear or inverse characteristics. The RDC employs the sigma–delta analog-todigital conversion (...

MQ-6 Semiconductor Sensor for Combustible Gas detection is a Sensitive sensor. The sensitive material of this gas sensor SnO2, which works with lower conductivity in clean air. When the target combustible exist, sensors higher along concentration rising. As increases current circuit results resistance. This change used to correspond, output signal concentration. has high sensitivity Methane, Pr...

Semiconductor sensors based on nanosized Pd-containing tin dioxide have been obtained by a sol-gel technique. Semiconductor gas-sensitive materials were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD) methods. Influence of Pd additives on sensitivity of the sensors to methane has been studied. Temperature dependences of electrical resistance in air and sensor...

A portable laser photoacoustic sensor for methane (CH₄) detection based on a field-programmable gate array (FPGA) is reported. A tunable distributed feedback (DFB) diode laser in the 1654 nm wavelength range is used as an excitation source. The photoacoustic signal processing was implemented by a FPGA device. A small resonant photoacoustic cell is designed. The minimum detection limit (1σ) of 1...

Exhaled methane concentration measurements are extensively used in medical investigation of certain gastrointestinal conditions. However, the dynamics of endogenous methane release is largely unknown. Breath methane profiles during ergometer tests were measured by means of a photoacoustic spectroscopy based sensor. Five methane-producing volunteers (with exhaled methane level being at least 1 p...