A micro multi-array sensor includes a substrate, a sensor electrode formed on the substrate, and a heater electrode formed on the substrate. The sensor electrode includes a first sensor electrode formed on the substrate and a second sensor electrode formed on an opposite surface of the substrate from the first sensor electrode. The heater electrode is disposed more adjacent to the first sensor electrode than the second sensor electrode.

A test chamber and a method for conditioning air in a temperature-insulated test space of a test chamber, which is sealable against an environment and serves for receiving test material, a temperature ranging from −20° C. to +180° C. being produced within the test space by means of a cooling device of a temperature control device of the test chamber, using a cooling circuit with carbon dioxide (CO.sub.2) as a cooling agent, using a heat exchanger in the test space, using a low-pressure compressor and using a high-pressure compressor downstream of the low-pressure compressor, using a gas cooler, using a storage means for the cooling agent and using an expansion valve, the temperature in the test space being controlled and/or regulated by means of a control device of the test chamber. A gaseous and/or liquid cooling agent is dosed in the storage means by means of a high-pressure valve of the cooling circuit downstream of the gas cooler, the storage means being connected to a medium-pressure side of the cooling circuit upstream of the high-pressure compressor and downstream of the low-pressure compressor via a medium-pressure bypass of the cooling circuit, the gaseous cooling agent being dosed in the medium-pressure side from the storage means by means of a medium-pressure valve when the low-pressure compressor is switched off.

A gas detector comprises a metal oxide semiconductor gas sensor whose resistance decreases in reducing gases and a digital information processing device that treats the output of the gas sensor and compares the output with a comparison value for gas detection. The digital information processing device extracts data representing the resistance of the gas sensor in air from the output of the gas sensor and generates the comparison value such that the larger the resistance of the gas sensor in air is, the larger the ratio between the resistance of the gas sensor in air and a resistance value corresponding to the comparison value is.

A concentration sensor assembly can include a vaporization chamber having a compound. The concentration sensor assembly may include a first flow path coupled to the vaporization chamber. The first flow path may direct a first gas to the vaporization chamber. A second flow path can direct a second gas out of the vaporization chamber. The second gas can include the compound and the first gas. A first sensor is disposed along the first flow path. The first sensor measures first data indicative of a first mass flow rate of the first gas. A second sensor is disposed along the second flow path. The second sensor measure second data indicative of a second mass flow rate of the second gas. A computing device may determine a concentration of the vaporizable substance within the second gas based on the first data and the second data.

A system for detecting an analyte gas in an environment includes a first gas sensor, a first contaminant sensor separate and spaced from the first gas sensor, and electronic circuitry in electrical connection with the first gas sensor to determine if the analyte gas is present based on a response of the first gas sensor. The electronic circuitry is further in electrical connection with the first contaminant sensor to measure a response of the first contaminant sensor over time. The measured response of the first contaminant sensor varies with an amount of one or more contaminants to which the system has been exposed in the environment over time.

A method includes applying heat to a metal oxide sensing element of a gas sensor, varying the heat applied to the metal oxide sensing element for at least a time interval, and measuring an electrical resistance of the metal oxide sensing element versus variation of the heat for a time interval. The measurement of electrical resistance of the metal oxide sensing element versus variation of the heat applied to the metal oxide sensing element is compared to a set of corresponding reference measurements associated with a plurality of different target gases. A further sensor parameter versus the variation of electrical resistance and variation of the heat applied is measured to obtain a three-dimensional trajectory corresponding to variation of the sensor resistance, the variation of said heat and the variation of the further sensor parameter. This comparing includes comparing the trajectory in three dimensions to a set of reference three-dimensional objects.

Provided are: a gas sensor which is able to have improved gas detection performance, while being capable of suppressing variation in the output characteristics among individual gas sensors; a gas detection device; a gas detection method; and a device which is provided with a gas sensor or a gas detection device. This gas detection device (10) is provided with: a heat sensitive resistive element (2); a lead part (22b) which is connected to the heat sensitive resistive element (2) by welding, while having no material being interposed therebetween; a gas sensor (1) which is thermally coupled to the heat sensitive resistive element (2), while comprising a porous gas molecule adsorption material (3) from which specific gas molecules are desorbed by means of heating; and an electric power supply unit which supplies electric power to the heat sensitive resistive element (2), thereby heating the heat sensitive resistive element (2).

Methods, devices, and systems for adjusting for air flow temperature changes in an aspirating smoke detector are described herein. In some examples, one or more embodiments include a blower configured to cause air to flow through the aspirating smoke detector, and a controller configured to determine a temperature of the air flowing through the aspirating smoke detector has changed by a particular amount and adjust a speed of the blower in response to compensate the air flowing through the aspirating smoke detector that has changed by the particular amount.

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 present invention provides a heater temperature control circuit including a heater and a control circuit that controls a temperature of the heater, wherein the control circuit includes a bridge circuit in which a first circuit and a second circuit are connected in parallel, and an operational amplifier connected to the bridge circuit, wherein in the first circuit, the heater and a resistor are connected in series, and a midpoint of the first circuit is connected to one input portion of the operational amplifier, and an output value V.sub.out from the second circuit is input to the other input portion of the operational amplifier, the output value V.sub.out being obtained by multiplying a division ratio of a target resistance value R.sub.h of the heater and a resistance value R.sub.1 of the resistor with a reference voltage V.sub.ref of the bridge circuit.