A gas sensor includes a first electrode, a gas detecting layer disposed on the first electrode, and an electric-conduction enhanced electrode unit being electrically connected to the first electrode and the gas detecting layer. The electric-conduction enhanced electrode unit includes an electric-conduction enhancing layer and a second electrode electrically connected to the electric-conduction enhancing layer. The electric-conduction enhancing layer is electrically connected to the gas detecting layer and is made of an electrically conductive organic material.

A gas sensor includes a first electrode, a gas detecting layer disposed on the first electrode, and an electric-conduction enhanced electrode unit being electrically connected to the first electrode and the gas detecting layer. The electric-conduction enhanced electrode unit includes an electric-conduction enhancing layer and a second electrode electrically connected to the electric-conduction enhancing layer. The electric-conduction enhancing layer is electrically connected to the gas detecting layer and is made of an electrically conductive organic material.

An optical gas concentration measurement apparatus is disclosed. The optical gas concentration measurement apparatus includes a thermally insulated enclosure that has a gas sample cell situated within. A thermally-insulating, light-guiding element passes through an access port of the thermally insulated enclosure and is configured to direct light from a light source outside of the thermally insulated enclosure to the gas sample cell. A light detector outside of the thermally insulated enclosure is optically coupled to the gas sample cell and an electronic assembly outside of the thermally insulated enclosure is configured to receive information from the light detector.

The disclosure includes a gas analysis system comprising a control system. In some embodiments, the control system comprises a computer monitoring host, an underground coal mine gas circuit control box including an intrinsically safe PLC, a sampling pump electrically coupled to the remote power control, an explosion proof safety power box electrically coupled to the intrinsically safe optical fiber switch, and an intrinsically safe gas chromatograph electrically coupled to the intrinsically safe optical fiber switch and the flameproof and intrinsically safe power box. In some embodiments, the gas analysis system comprises a gas pipeline system having an instrument sequence tube coupled to the carrier gas output pressure sensor, the carrier gas proportional solenoid valve, the carrier gas path pressure sensor, a manual carrier gas pressure reducing valve, and a carrier gas storage.

A MEMS photoacoustic gas sensor includes a first membrane and a second membrane opposing the first membrane and spaced apart from the first membrane by a sensing volume. The MEMS photoacoustic gas sensor includes an electromagnetic source and communication with the sensing volume to deflect the first membrane and the second membrane.

A temperature-regulated chemi-resistive gas sensor includes a sensor surface including a chemically sensitive sensor layer including an active material for adsorbing and desorbing gas molecules of an analyte gas. A predetermined time-continuous periodic temperature profile is applied for periodically heating the sensor surface. An electrical sensor layer conductance signal is determined and time windows are applied to the sensor layer conductance signal. For one or more of the time windows, discrete frequency spectrum data of the sensor layer conductance signal is obtained, and a current gas concentration of the analyte gas is determined based on the obtained discrete frequency spectrum data.

A method for sensing gas by a gas sensing device, the method may include generating, by a semiconductor temperature sensing element that is spaced apart from a gas reactive element and is thermally coupled to the gas reactive element, detection signals that are indicative of a temperature of the gas reactive element; wherein the gas reactive element and the semiconductor temperature sensing element are of microscopic scale; and processing, by a readout circuit of the gas sensing device, the detection signals to provide information about a gas that affected the temperature of the gas reactive element.

A microelectromechanical (MEMS) gas sensor operating based on Knudsen thermal force is disclosed. The sensor includes a substrate, at least one stationary assembly that is fixedly coupled to the substrate, and at least one moveable assembly that is positioned above the substrate which is biased to move substantially according to a main axis and juxtaposed with the at least one stationary assembly.

An embodiment of a gas analyzer is described that comprises a light source configured to produce a substantially collimated first beam with a diverging angle of less than about 15 degrees; a gas cell comprising an inlet configured to introduce a gas into the gas cell, an outlet configured to remove the gas from the gas cell, and a plurality of mirrors configured to reflect the substantially collimated first beam within the gas cell; and a detector configured to generate a signal in response to the substantially collimated first beam.

A spectroscope using single-photon counters and a chip-integrated lithium niobate micro-ring filter to measure the atmospheric CO2 absorption spectrum passively is disclosed. By thermo-optically sweeping the filter over 150 pm and referencing the resulting photon counts to a bypass channel, the absorption spectrum can be sampled at an ultrahigh-resolution of 6 pm. The spectroscope can be a part of a ground-based field system, wherein the CO2 absorption through the atmosphere can be characterized by counting the solar photons across the absorption line around 1572.02 nm, which agrees well with its transmission spectrum at standard atmospheric pressure.