Apparatus for measuring at least one property of a fluid comprises a capacitive fluid sensor (110) comprising a first electrode (111) and a second electrode (112) with a sensing region (113) between the electrodes. The apparatus comprises an alternating signal source (120) configured to apply an alternating drive signal to the capacitive fluid sensor (110). The apparatus comprises a processing apparatus (200) configured to receive a sense signal from the capacitive fluid sensor (110) and the alternating drive signal. The processing apparatus (200) is configured to: determine a complex difference signal comprising an in-phase difference component between the drive signal and the sense signal and a quadrature difference component between the drive signal and the sense signal; determine the at least one property of the fluid based on both the in-phase phase difference component and the quadrature difference component of the difference signal.

A gas sensor is formed by a thin-film semiconductor metal-oxide gas sensing layer, with a thermally conductive and electrically-insulating layer in direct physical contact with a back of the gas sensing layer to carry the gas sensing layer. Sensing circuitry applies a voltage to the gas sensing layer and measures a current flowing through the gas sensing layer. The current flowing through the gas sensing layer is indicative of whether a gas under detection has been detected by the gas sensing layer, and serves to self-heat the gas sensing layer. A support structure extends from a substrate to make direct physical contact with and carry the thermally conductive and electrically insulating layer about a perimeter of a back face thereof, with the support structure shaped to form an air gap between the back of the thermally conductive and electrically insulating layer and a front of the substrate.

A method of operating a gas sensing device is described. The method includes receiving a signal indicative of a value of resistance of a gas sensing element, processing the signal received to compute a value of a gas concentration, performing a comparison of the value of gas concentration to a threshold, and, based on the outcome of a diagnosis procedure, setting the device to an alert signal issue state as a function of the outcome of the comparison. The diagnosis procedure includes computing a set of parameters indicative of the state of the gas sensor circuit, and classifying the gas sensor circuit in one of a first, a second and a third class based on the parameters.

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.

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 sensing device includes at least one vibration sensor that responds to sensed vibrations. At least one drive-sense circuit is coupled to the vibration sensor, wherein the at least one drive-sense circuit includes: a first conversion circuit configured to convert a receive signal component of a sensor signal corresponding to the at least one vibration sensor into the sensed signal, wherein the sensed signal indicates a change in an electrical characteristic associated with the at least one vibration sensor; and a second conversion circuit configured to generate, based on the sensed signal, a drive signal component of the sensor signal corresponding to the at least one vibration sensor.

Provided is a gas detection device that includes a gas sensor, a power supply circuit that applies voltage to the gas sensor, and a control circuit that determines whether a leak of gas is present. The power supply circuit includes a reset power source that generates a first voltage, and a detection power source that generates a detection voltage for measuring resistance of a metal-oxide layer of the gas sensor. When a value of a current flowing through the metal-oxide layer is a predetermined value ITH or greater, the reset power source applies the first voltage to the gas sensor to perform a reset of resetting the metal-oxide layer of the gas sensor to a high-resistance state, and the control circuit determines that a leak of gas is present, depending on a state in which the reset is performed after the reset is performed for the first time.

The present disclosure provides methods for determining impedance of an electrochemical device by electrically connecting a variable impedance in parallel with the electrochemical device; electrically connecting a power supply to the electrochemical device, the power supply generating a power supply current; modulating a current through the variable impedance; measuring a stack current flowing through the electrochemical device; measuring, at the electrochemical device, a voltage across at least a portion of the electrochemical device; and calculating, based on the measured stack current and the measured voltage, the impedance of the electrochemical device. Systems for performing such methods are also provided.

A measurement device includes: a resistance measurement unit that measures an electrical resistance of a measurement target; a first measurement unit, including a detector that detects information indicating a first physical property other than the electrical resistance of the measurement target, that measures the first physical property from a detection result from the detector; a second measurement unit, including a detector that detects information indicating a second physical property other than the electrical resistance and the first physical property of the measurement target, that measures the second physical property from a detection result from the detector, in which a length of time from a start of driving the detector until a start of actual measurement is longer in the second measurement unit than in the first measurement unit; and a control unit that performs first control causing the first measurement unit to execute a measurement operation of measuring the first physical property in parallel with a measurement operation by the resistance measurement unit, and performs second control causing the second measurement unit to execute a measurement operation of measuring the second physical property in parallel with the measurement operation by the resistance measurement unit and also causing the second measurement unit to start the driving of the detector in the second measurement unit before the start of the driving of the detector in the first measurement unit.

A gas detection probe includes a shell and a detection element. The detection element includes a first element and a second element. The shell includes a first shell portion, a second shell portion, and a third shell portion. The second shell portion and the third shell portion are mated and formed on an outer periphery of the first shell portion. The shell has a first cavity and a second cavity. The first shell portion is in sealing engagement with the third shell portion. The second shell portion is provided with a guide hole portion communicated with the second cavity. The first element is accommodated in the first cavity. The second element is accommodated in the second cavity. The gas detection probe of the present disclosure is more beneficial to realize miniaturization. A manufacturing method of the gas detection probe is also disclosed.