A MEMS gas sensor is disclosed. In an embodiment a MEMS gas sensor includes a carrier having a recess, a gas sensitive element arranged in the recess and a shielding layer at least partially covering the recess.

Provided are a gas detection method and a gas detector which have a high durability to silicone poisoning and is capable of detecting the type and the concentration of a target gas to be detected with certain accuracy even when the detector is used in an environment where a silicone compound exists. The gas detector employs a contact combustion-type gas sensor which includes two gas detection elements, each intermittently driven, and in which only one gas detection element is supplied with a gas through a silicone removal filter. Acquired in an energization duration of each of the gas detection elements are two or more pieces of output data by the one gas detection element and two or more pieces of output data by the other gas detection element, which constitutes output variation patterns for a test gas. The output variation patterns are contrasted to a reference output variation pattern of each of four largely divided types of reference gases of a paraffinic hydrocarbon gas, a solvent gas, a hydrogen gas, and an argon gas, with the reference output variation patterns being acquired in advance, thereby identifying the type of the target gas being detected in the test gas.

An odor detection device includes a filter including a metal-organic framework in which a metal ion and an organic ligand are bonded and an odor sensor detecting a plant-derived odor substance having a straight chain structure which is included in a sample gas passing through the filter. The filter transmits the odor substance included in the sample gas and removes a volatile compound other than the odor substance from the sample gas.

A microsensor for monitoring phosphine and a preparation method thereof are provided, where the microsensor includes an interfering substance removal module, used to remove other impurity gases and keep a phosphine gas; a phosphine signal measuring module, used for measuring a concentration of the phosphine gas; a guard electrode, used to consume excess phosphine gas in the microsensor; and a power supply module, used for supplying power to the phosphine signal measuring module and the guard electrode; the power supply module is respectively connected with the phosphine signal measuring module and the guard electrode; and the interfering substance removal module is located at a front end of the guard electrode.

An analyzer for detection of a target compound in a complex gas mixture in the gas phase includes a detector for detecting the target compound and further has a sensing cavity. The detector is arranged in the sensing cavity. The analyzer also has a separate first membrane that is equipped to close the cavity and simplifies the composition of the complex gas mixture into a first gas mixture, wherein the first gas mixture includes the first target compound and wherein the first membrane is equipped to let the first gas mixture traverse through the first membrane into the sensing cavity. The detector is equipped to detect the first target compound.

The present invention includes a first flow path through which a sample gas flows, a first analyzer that is provided in the first flow path to measure total hydrocarbon concentration in the sample gas, a second flow path through which the sample gas flows, a non-methane non-ethane cutter that is provided in the second flow path to remove the hydrocarbon components other than the methane and the ethane in the sample gas, a second analyzer that is provided downstream of the non-methane non-ethane cutter in the second flow path to measure the total methane ethane concentration of the methane and the ethane in the sample gas, and a calculation part that calculates the concentration of the hydrocarbon components other than the methane and the ethane in the sample gas with use of the total hydrocarbon concentration by the first analyzer and the total methane ethane concentration by the second analyzer.

A gas detector comprises a gas detection unit and a filter introducing surrounding atmosphere to the gas detection unit. The filter comprises a gas-permeable organic polymer membrane having an acidic group or a basic group.

A gas detection method includes a first process, a second process, and a third process. The first to third process include changing routes to be followed by gases into first to third routes, respectively. The first route follows a first passage, a sensor chamber, and a second passage in this order. The second route follows a sample gas supply path, which bypasses a filter unit, and the sensor chamber in this order and allows the gas to be exhausted without letting the gas pass through the filter unit while flowing from the sensor chamber. The third route follows the first passage and the sensor chamber in this order and allows the gas to be exhausted without letting the gas pass through the filter unit while flowing from the sensor chamber.

There is provided a system (1) including a monitoring unit (50) that analyzes, using a sensor (51), components of a first gas which may include first components and a pre-separation unit (30) disposed upstream of the monitoring unit. The pre-separation unit includes a first supply line (31) that supplies the first gas (35) to the monitoring unit; a second supply line (32) that supplies a second gas (36), which includes components obtained by removing the first components from the first gas using a first separator (40), to the monitoring unit; and an automatic valve station (38) that periodically switches between the first supply line and the second supply line to alternately supply the first gas and the second gas to the monitoring unit.

A gas analysis system for analyzing dissolved gas in electrical insulating fluid includes a trap that selectively captures or releases one or more gases, a temperature control device for controlling a temperature of the trap that determining whether the trap is in a gas capture mode or a gas release mode, and a gas sensor for analyzing the gas that was not selectively captured by the trap. The trap may be heated to a first temperature that enables the gas to be adsorbed by the trap, and the trap may be heated to a second temperature that enables the gas to be desorbed by the trap. The gas analysis system may further include a gas flow diverter for directing gas flow past the trap. The captured or released gases may be interfering matrix gases. A method and analyzer for analyzing dissolved gas in an electrical insulating fluid are also disclosed.