A device includes: a chip, which includes a oscillatable cantilever with a first piezoelectric transducer for exciting cantilever oscillation, wherein the first cantilever extends into a cavity of the chip; a cantilever temperature sensor in an end section of the cantilever; a second temperature sensor spaced from the cantilever; a heating element located in the free end section of the cantilever and separated from the second temperature sensor by at least one cavity section; and an evaluation unit for determining density and viscosity as well as thermal conductivity and specific heat capacity of a gas mixture based respectively on oscillation characteristics of the cantilever and measured values of gas temperature from the cantilever temperature sensor, the second temperature sensor and a power consumption of the heating element.

In a preferred embodiment, there is provided a quartz crystal microbalance comprising a pair of electrodes and a quartz crystal disposed therebetween, one said electrode operable as a sensing electrode for interacting with an analyte, wherein said sensing electrode comprises an array of sensing electrode members positioned within a sensing electrode surface portion on the quartz crystal.

In an embodiment an electro-thermal device includes a heater, a readout circuit, a digital controller having a first input coupled to a first output of the readout circuit and a digital sigma-delta modulator having a first input coupled to an output of the digital controller and an output coupled to the heater.

The functions of the odor (smell, odor, reek etc. have the same meaning) detecting process with the same raw water includes two functions, that is: a function of detecting an odor by a downward substitution method that substitutes, in a sensor portion, heavy odorous substances to a bottom portion and light normal air to an upper portion by a four-stage humidity removal process in which high humidity air which is first generated in a vaporizing portion is made into medium-humidity air with a dehumidifying portion, which is then made into low-humidity air with a constant-temperature portion, and then two or more types of sensor elements are exposed to dry air at the sensor portion; and a second function of detecting poison using fish in a monitoring water tank, which is detected with another process such as surveillance camera, image processor, periphery controller and the like. The above two functions are compactly incorporated as an integrated type into a single cabinet.

In accordance with an embodiment, a method of measuring a gas concentration includes modulating an infrared light source according to a frequency-hopped sequence or according to a pulse sequence, receiving a microphone signal from an output of a microphone acoustically coupled to a gas exposed to infrared light produced by the infrared light source; bandpass filtering the microphone signal using a bandpass filter; and estimating the gas concentration from the filtered microphone signal.

A gas sensor includes: a main elongate gas chamber with a supply opening arranged on a first end of the main gas chamber and a discharge opening positioned opposite the supply opening and arranged on a second end of the main gas chamber, to permit gas to flow through the main gas chamber; a magnetic field device providing a magnetic field in the main gas chamber; and an ultrasonic transmitter and receiver sensor arranged on either the first or second end of the main elongate gas chamber for directing an ultrasonic wave along a longitudinal axis of the main elongate gas chamber, an opposite end of the main elongate gas chamber being reflective for an ultrasonic wave, or an ultrasonic transmitter sensor arranged on a first end of the main elongate gas chamber and an ultrasonic receiver sensor arranged on a second end of the main elongate gas chamber.

Example computer systems, computer apparatuses, computer methods, and computer program products are disclosed for testing an ultrasonic gas leak detection device. An example method includes determining a rotary position of a rotary selector of the handheld ultrasonic testing device. The method further includes determining whether the rotary position of the rotary selector corresponds to a first testing mode for testing the ultrasonic gas leak detection device or a second testing mode for testing the ultrasonic gas leak detection device. The method further includes generating a first ultrasonic signal for testing the ultrasonic gas leak detection device in response to determining that the rotary position of the rotary selector corresponds to the first testing mode. The method further includes generating a second ultrasonic signal for testing the ultrasonic gas leak detection device in response to determining that the rotary position of the rotary selector corresponds to the second testing mode.

A sensor system for detecting water or air in a hollow member comprises a first acoustic sensor assembly in a first housing on one side of the hollow member, a second acoustic sensor assembly in a second housing on the opposite side, a controller unit connected to the first and/or second sensor assemblies, and where the first and second sensor assemblies and the controller unit are provided with power supply. Each of the first and second sensor assemblies comprises a set of probes connected to electronics for transmitting and receiving signals, and where the housings comprise fastening means for connecting the housings and the probes to the hollow member. The controller unit comprises a microcontroller, software for controlling and coordinating transmission and reception of signals between said probes, and means for registering and logging data generated by the sensor assemblies. A method detects water or air in a hollow member.

A vapor and/or gas concentration and temperature sensor includes a resonating structure having a first side with a functionalized surface and a second side opposite the first side, a first resonant frequency of a first vibration mode, and a second resonating frequency of a second vibration mode. Drive and sensing electrodes face the second side of the resonating structure. A direct current bias source is coupled to the resonating structure. A first AC voltage source provides the resonating structure with a first voltage having a frequency corresponding to the first resonant frequency. A second AC voltage source provides the resonating structure with a second voltage having a frequency corresponding to the second resonant frequency. A read-out circuit determines a vapor and/or gas concentration based on a difference between the frequency of the first voltage and a first read-out frequency and determines a temperature based on a difference between the frequency of the second voltage and a second read-out frequency.

A fluid sensor includes a housing structure forming a cavity for an IR emitter for emitting an IR radiation in the cavity, wherein the IR radiation has a center wavelength for providing an interaction of the IR radiation with the target fluid resulting in a temperature change in the cavity or in the housing structure, which effects a mechanical pulse in the housing structure, and an inertial detection sensor mechanically coupled to the housing structure for sensing the mechanical pulse in the housing structure.