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.

An apparatus with a built-in self-test includes a sensor electrode, an impedance sensor coupled to the sensor electrode to measure a test impedance of the sensor electrode as influenced by an external load, a secondary electrode disposed adjacent to the sensor electrode to inductively couple with the sensor electrode and influence the external load on the sensor electrode, a first switch coupled to the secondary electrode to selectively change a second impedance of the secondary electrode, and a controller coupled to the impedance sensor and the first switch. The controller includes logic for adjusting the first switch to wirelessly load the sensor electrode with the secondary electrode in a predetermined impedance state, measuring the test impedance with the impedance sensor while the secondary electrode is in the predetermined impedance state, and comparing the measured test impedance against a threshold impedance range to perform a self-test.

The present invention refers to a gas sensor comprising a hybrid material of perovskite and graphene, to the method for obtaining said sensor and to the gas detection method using said sensor.

In a multi-channel resistance-based gas sensor system, the multi-channel array includes gas sensor channels respectively connected to resistive type gas sensors. The pre-processing unit selects a current mode, a resistance mode, or an external resistance mode, analyzes a sensing value obtained from any one of the gas sensor channels based on the selected mode and outputs a voltage value corresponding thereto. The analog-to-digital converter (ADC) converts the voltage value to digital data. The control unit controls the pre-processing unit to execute one of the current mode for analyzing a sensing value smaller than or equal to a preset first resistance value, the external resistance mode for analyzing a sensing value greater than or equal to a preset second resistance value greater than the preset first resistance value and the resistance mode for analyzing a sensing value between the preset resistance first value and the preset second resistance value.

The disclosure concerns an electronic chip including a resistive region and a first switch of selection of a first area in contact with the resistive region.

A device for detecting isotopes includes an isotope portion including a material including an isotope of an element, a reaction control portion to cause a chemical reaction of the material, and an electrical parameter portion to measure a change in an electrical parameter of the material, where the change in the electrical parameter is caused by the chemical reaction, and where the change in the electrical parameter is dependent on the isotope in the material, to detect the isotope by comparing the change in the electrical parameter of the material with a known electrical parameter associated with a known isotope.

A particulate matter (PM) sensor circuit arrangement includes a PM sensor. The sensor includes, integral therewith, a PM sensor resistor, a resistive temperature device (RTD) resistor, and a heater resistor. The PM sensor includes four terminal pins, of which a) a first terminal pin is connected to one terminal of the PM sensor resistor; a second terminal pin is connected to one terminal side of said RTD resistor; c) a third terminal pin being connected to one terminal of a heater resistor; and d) a fourth common terminal pin is connected to respective opposite terminals of the PM sensor resistor, RTD resistor, and heater resistor to the first, second, and third terminal pins. The fourth common terminal pin is operationally connected to a boost or voltage supply and the first pin is connected to a low side line.

Provided is a method of evaluating a silicon layer, including forming an oxide film on a surface of a silicon layer, performing a charging treatment of charging a surface of the formed oxide film to a negative charge, and measuring a resistivity of the silicon layer that has been subjected to the charging treatment by a van der Pauw method.

A magnetoresistive hydrogen sensor and sensing method thereof, wherein the hydrogen sensor comprises a substrate located in an X-Y plane, magnetoresistive sensing units and magnetoresistive reference units located on the substrate. The magnetoresistive sensing units are electrically connected to form a sensing arm, and the magnetoresistive reference units are electrically connected to form a reference arm. The sensing arm and the reference arm are electrically interconnected to form a referenced bridge structure. The magnetoresistive sensing units and the magnetoresistive reference units may be AMR units having the same magnetic multilayer thin film structure, GMR spin valves, or GMR multilayer film stacks having the same magnetic multilayer thin film structure. The magnetoresistive sensing units and the magnetoresistive reference units are respectively covered with a Pd layer, and a passivating insulation layer is deposited over the Pd layer of the magnetoresistive reference units. The magnetic multilayer thin film structure is made into a serpentine strip circuit by a semiconductor micromachining process. The hydrogen detecting method comprises placing the hydrogen sensor in a gas environment containing hydrogen, the Pd layers covering in the magnetoresistive sensing units absorb hydrogen to change the perpendicular magnetic anisotropy of ferromagnetic layers in the magnetic multilayer thin film structures of the magnetoresistance sensing units, which makes the magnetic moment of the ferromagnetic layer rotate to produce a change in the magnetoresistance value that correlates to the hydrogen concentration. The resulting change of the magnetoresistance value changes the output voltage value of the referenced bridge structure, and this change of the output voltage value of the referenced bridge structure is used to measure the hydrogen concentration.

A method for evaluating the functionality of a ceramic sensor for detecting soot, the sensor including two measurement electrodes exposable to an exhaust and spaced apart from one another, and an electrical resistance heating element. The method includes: activating the resistance heating element to heat up the sensor and to burn soot off the two measurement electrodes; then deactivating the resistance heating element; then waiting for a first predetermined time period and/or waiting until a signal that is received from the sensor and represents the sensor temperature reaches a first predefined value; then measuring a first variable representing the electrical resistance between the measurement electrodes; then evaluating the functionality of the sensor based on the first variable representing the electrical resistance between the measurement electrodes.