The present invention generally relates to a system for preparing reduced graphene-cobalt chromate composite for humidity sensor applications comprises a first glass beaker for pouring 3-7 grams of sucrose; a preheated muffle furnace for heating the first glass beaker containing sucrose for 5-15 minutes at 450-500° C. in an oxygen environment and obtaining the black foam of rGO after hydrating the sugar; a second glass beaker for mixing 3-7 grams rGO, 3-7 grams carbamide, 3-7 grams cobaltous, and 3-7 grams chromium nitrate and dissolving with double-distilled water; and a magnetic stirrer for stirring the mixed solution for 450 minutes to generate a homogenous solution and burning the uniform mixture at 425° C. in the preheated muffle furnace for 20 minutes to obtain graphene-cobalt chromate composite.

Disclosed are conjugated polymers bearing chemical probes and the use thereof for the preparation of chemical sensors based on carbon nanotubes allowing the selective detection of analytes in water.

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 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 sensor arrangement includes a switchable voltage source having a source output for alternatively providing a first and a second excitation voltage, an integrator having an integrator input and an integrator output, a sensor resistor having a first terminal coupled to the source output, a reference resistor having a first terminal coupled to a second terminal of the sensor resistor and a second terminal coupled to the integrator input, and a comparator having a first comparator input coupled to the integrator output.

An electronic device material includes: carbon nanotubes having a purity of Semiconductor Carbon Nanotubes of 80% by mass or more; and a n-type semiconductor.

A compact explosive detecting system collects explosive residues in the form of vapor powder. The residues are accumulated on a desorber which is subjected to pyrolysis to release a gaseous sample. The sample is pumped to a detecting system through a metering valve. A luminol cell reacts with the gaseous sample to create chemiluminescence, the light output of which is measured by a photo multiplier tube. The light intensity is indicative of the amount of explosive present. Based on the amount of explosive present, a metering valve is adjusted to pass the gaseous sample into a highly sensitive metal oxide sensor array to detect NO.sub.2 from nitrogen containing explosive and CO/CO.sub.2 from non nitrogen containing explosive. The metal oxide sensor array reliably selects explosives from those compounds indicating chemiluminescence.

A sensor component and a mobile communication device including a sensor component are disclosed. In an embodiment a sensor component includes a subcomponent configured to sense a gas level including a resistive heater and a gas sensitive element disposed on the resistive heater; a package enclosing a cavity and accommodating the subcomponent, the package including a first opening in a position facing the gas sensitive element of the subcomponent and a second opening configured to allow a flow of gas to enter the package through the first opening and exit the package through the second opening; and an evaluation circuit configured to generate an output signal indicative of a speed of the flow of gas in response to electrical power to be supplied to the resistive heater.

A microelectromechanical sensor includes a base, a heater provided on the base, and a sensing electrode including a sensing portion. The heater includes a heating portion. The heater and the sensing electrode are provided at different layers in a stacking direction, and the sensing electrode is electrically insulated from the heater. On a reference plane in the stacking direction, a projection of the sensing portion of the sensing electrode is entirely covered by a projection of the heating portion of the heater.

Numerous embodiments of a gas sensor and associated methods are described. In one embodiment, a gas sensor comprises a single wire. The resistance of the wire is measured for different temperatures, or the current through the wire or the voltage across the wire is measured for a constant temperature, and a profile for the surrounding gases is generated, enabling the surrounding gases to be identified. In another embodiment, a gas sensor comprises a first wire and a second wire in close proximity, where the first wire is used to generate temperature conditions, and the resistance of the second wire is measured for the different temperature conditions, or the current through the wire or the voltage across the wire is measured for a constant temperature. A profile for the surrounding gases is generated, enabling the surrounding gases to be identified.