A gas monitor configured to monitor at least one target gas in an environmental mixture, by separating and concentrating the target gas and then adjusting for the concentration factor. The adjustment may also take into account sensor sensitivities to other gases. Methods for adjustment of target gas results and increasing accuracy of monitoring are described.

A gas sensor includes a support structure with a cavity, a sensing element sensitive to a gas and arranged in the cavity, and a filter spanning the cavity. The filter is a size selective filter.

The invention is directed to a gas sensor that includes a hotplate, a support structure, a gas selective filter, and circuitry. The support structure is configured to define a cavity. The gas selective filter is held by the support structure and spans the cavity. Various components are connected to the circuitry, and may include a temperature sensor element, a gas sensing element, and a heater. The temperature sensor element is configured to sense a temperature T.sub.f of the filter. The gas sensing element is sensitive to a target gas in the cavity. The heater is in thermal communication with the gas sensing element. The circuitry is configured to operate the sensing element, estimate a temperature T.sub.f of the filter, and regulate the heater. The circuitry regulates an extent to which power is supplied to the heater based on the estimated temperature T.sub.f of the filter.

The invention relates to a sensor device (1) for detecting a gas (G), particularly a permanent gas such as H.sub.2, CO, CO.sub.2, CH.sub.4, comprising: an adsorption filter (30) comprising a body (2) consisting of a molecular sieve material, a sensing element (10) for detecting said gas (G), and a carrier (4) for carrying the sensing element (10), wherein the carrier (4) comprises an opening (50) via which said gas (G) to be detected can reach the sensing element (10), and wherein the adsorption filter (30) is connected, particularly glued, to the carrier (4) and closes said opening (50) so that said gas (G) to be detected can diffuse through said body (2) towards the sensing element (10).

Embodiments of the present specification provide methods and systems for maintaining accuracy and precision of calibration for a detector. The methods and systems include reducing the humidity of an internal calibration assembly by directing flow path of dry air periodically through the internal calibration assembly.

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.

A method of determining a presence, concentration or change in concentration of a first or second material in an environment is disclosed. The method comprises measuring a response of a first sensor to the first and second material, wherein the first sensor is one of a metal oxide sensor, an electrochemical sensor, a photoionisation sensor, an infrared sensor, a pellistor sensor, an optical particle monitor, a quartz crystal microbalance sensor, a surface acoustic wave sensor, a cavity ring-down spectroscopy sensor, or a biosensor. The method further comprises measuring a response of a second sensor to the first and second material, wherein the second sensor is another one of a metal oxide sensor, an electrochemical sensor, a photoionisation sensor, an infrared sensor, a pellistor sensor, an optical particle monitor, a quartz crystal microbalance sensor, a surface acoustic wave sensor, a cavity ring-down spectroscopy sensor, a biosensor or a field effect transistor sensor. The method further comprises determining from first and second sensor measurements, a presence, concentration or change in concentration of the first or second material.

A small-sized, portable enclosure protects a gas sensor against degradation due to environmental exposure and changes in atmospheric conditions. The protective enclosure includes an inlet for introduction of a gas into the enclosure, an outlet for release of the gas upon completion of a sensing run, and a number of in-line filters that remove from the inflowing gas sample analytes, contaminants, and other materials that can compromise the integrity of the sensor or cause the sensor to degrade over time. The enclosure does not include any filters during the measurement phase of the sensing run in order to allow the gas sensor to accurately measure an unmodified gas mixture and/or analyte.

The invention relates to a method and a system for analyzing rare gases present in a gaseous fluid (1). According to the invention, initially, the rare gases are extracted from the gaseous fluid by trapping by means of a getterizing substrate (5), then superconcentration of the rare gases is produced before injection (8) into the measuring instruments (9). By virtue of the invention, it is possible to increase the partial pressure of the rare gases in the gases to be analyzed before their injection into the analysis instruments.

Provided is a reducing gas detection sensor which has sensitivity improved as compared to that of the related art, and in which power consumption is decreased. The reducing gas detection sensor includes: a reducing gas detection material including a palladium compound and a carbon compound, and having reactivity with a reducing gas; and a unit configured to measure a conductivity of the reducing gas detection material.