Abstract: At a sensor electrode of a steering wheel, a protruding portion protrudes from a main body portion. A first thread and a second thread each extend in the protruding portion and effect conduction between a terminal at the protruding portion and a main body portion. Therefore, even if there is no conduction between the first thread and the second thread at intersection portions between the first thread and second thread in the protruding portion, the first thread and the second thread may each effect conduction between the terminal and the main body portion, and a degradation of conduction performance of the sensor electrode may be suppressed.

Abstract: An image forming apparatus includes: a main body that forms an image on a sheet; and a removable unit that is attachable and removable to and from the main body, wherein the removable unit includes a first unit attachable to an outside of the main body, and is packable separately from the main body in a state removed from the main body.

Abstract: A dispensing system for a beverage comprises in a tap system a bore for housing a duct. Along the bore, close to or on the duct, at least two electrodes are provided such that at least at some locations along the duct, the two electrodes are provided opposite to one another with the duct in between, thus constituting a capacitor. An oscillating signal is provided to one electrode and a signal is read out from the other electrode. As a beverage is drawn through the duct in a container, capacitance of the capacitor changes. The flowing beverage may have different characteristics, but capacitance may also change as the beverage in the duct is in conducting contact with a container that may be in contact with a ground contact. The change of capacitance results in a change of the amplitude of a detection circuit connected to the second electrode.

Abstract: A capacitive sensing device includes a switch circuitry, a counter circuit, a comparator circuit, an amplifier circuit including first and second input terminals and an output terminal, and a feedback capacitor coupled between the output terminal and the first input terminal. The switch circuitry transmits a reference voltage to the second input terminal and couples the first input terminal to the output terminal during a first phase, transmits another reference voltage to the second input terminal during a second phase, and adjusts a voltage of the output terminal during a third phase. The counter circuit starts counting and the comparator circuit generates the control signal according to the output voltage and the second reference voltage during the third phase. The counter circuit stops counting according to the control signal to generate a count value indicating a capacitance value change of a capacitor under-test coupled to the first input terminal.

Abstract: A switched capacitor converter includes a first leg between ground and a first voltage node, a second leg between ground and a second voltage node, a first flying capacitor connected between a first switch common node and a third switch common node of the first leg, a second flying capacitor connected between a first switch common node and a third switch common node of the second leg, a third flying capacitor connected between the first voltage node and the second voltage node, a first upper switch connected between the first voltage node and ground, and a second upper switch connected between the second voltage node and an input terminal.

Abstract: One or more examples of the present disclosure relate generally to systems and methods for canceling mutual capacitive effects in a capacitance measurement. Some examples relate to providing a driven shield during capacitance measurement. Some examples relate to providing such a driven shield using rail-to-rail voltage.

Abstract: Methods, systems, and devices for detection of a protective cover film on a capacitive touch screen are described. A device may include a capacitive touch screen having a surface and a sensor grid underneath the surface having a set of conductive columns and a set of conductive rows. The device may measure a mutual capacitance between a subset of conductive columns or a subset of conductive rows associated with a sensor grid, and compare the measured mutual capacitance between the subset of conductive columns or the subset of conductive rows to a baseline mutual capacitance associated with the set of conductive columns and the set of conductive rows. According to the comparison, the device may determine a presence of a protective layer in contact with the surface of the capacitive touch screen, and adjust an operating characteristic of the sensor grid.

Abstract: A displacement sensor comprising: a first electrode and a second electrode displaceably mounted relative to the first electrode; capacitance measurement circuitry configured to make measurements of a capacitance associated with the first and second electrodes and to generate analogue capacitance measurement signals in response thereto; compensation circuitry configured to generate a compensated analogue capacitance measurement signal by reducing a magnitude of a current analogue capacitance measurement signal by an amount indicated by a compensation signal derived from at least one previous analogue capacitance measurement signal; and processing circuitry configured to digitise the compensated analogue capacitance measurement signal and to determine if there is a displacement of the second electrode relative to the first electrode based on the compensated analogue capacitance measurement signal.

Abstract: An input apparatus includes at least one operating area on an operating surface, at least one first sensing electrode corresponding to the operating area, a plurality of electrodes around the first sensing electrode, and a control unit configured to, when contact of an operating body with the operating area is detected by the first sensing electrode, make control different according to a contact operation on the one operating area according to a sum of capacitance values of electrodes of the plurality of peripheral electrodes around the operating area where the contact of the operating body is detected.

Abstract: Diverse applications from particle physics experiments to lidar are driving cost and current reduction in giga-hertz sampling rate high-resolution data conversion. Multiple imagers captures a single pixel of data and require processing at very high speed. High-bandwidth high-rate signal sampling, analog-to-digital conversion, and transfer of large amounts of data to a digital data acquisition block are required in such systems. Dynamic range, power consumption, and transfer of high-speed, high-bit width data are key implementation challenges. Data acquisition architectures optimized for specific requirements of such systems may facilitate system implementation and reduce overall system cost.

Abstract: The disclosure relates to detecting and clearing debris from a sensor window. For instance, a system may include the sensor window and one or more processors. The sensor window may include a transparent thin film conductor. The one or more processors may be configured to identify a change in capacitance using the transparent thin film conductor, detect debris on the sensor window using the change in capacitance, and activate a cleaning system in order to clear the detected debris from the sensor window.

Abstract: A device (1) for monitoring a response of a subject body (2, 21, 211) comprises an emitter (3) for emitting an input signal (5, 51, . . . ) and a receiver (4) for receiving an output signal (6, 61, . . . ). A first response (R1) of the subject body (2, 21, 211) is evaluated from the comparison between the signals. A further emitter (31, 311, . . . ) evaluates a second response (R2), wherein one of the responses is selected for a further monitoring of the response, and/or at least one further receiver (41, 411, . . . ) evaluates a third response (R3), wherein either the first response (R1) or the third response (R3) is selected for a further monitoring of the response, and/or wherein the input signal (5, 51, . . . ) is an electromagnetic field and the device (1) further comprises a signal modulator (9) which alters the input signal (5, 51, . . . ).

Abstract: According to one embodiment, a sensor includes a first member including a first member surface, and a first element part. The first element part includes a first fixed electrode fixed to the first member surface, and a first movable electrode facing the first fixed electrode. The first fixed electrode is along the first member surface. A gap is located between the first movable electrode and the first fixed electrode. The first movable electrode includes a first surface and a second surface. The first surface is between the first fixed electrode and the second surface. At least one of the first surface or the second surface is non-parallel to the first member surface.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed for adaptive synchronous rectifier control. An example apparatus includes an adaptive off-time control circuit to determine a first voltage and a second voltage when a drain voltage of a switch satisfies a voltage threshold, the first voltage based on a first off-time of the switch, the second voltage based on the first off-time and a first scaling factor, determine a third voltage based on a second scaling factor and a second off-time of the switch, the second off-time after the first off-time, and determine a third off-time of the switch based on at least one of the second voltage or the third voltage. The example apparatus further includes a driver to turn off the switch for at least the third off-time after the second off-time.

Abstract: Systems and methods to estimate trapped charge for a controlled automatic reclose of a power line using a ganged switching device are described herein. For example, an intelligent electronic device (IED) may calculate a voltage amount associated with trapped charge of each phase of a power line based on voltage measurements of the power line. The IED may send a signal to close a ganged switching device at a time based at least in part on the trapped charge of each phase of a power line.

Abstract: A self-standing sandwich structure includes at least one capacitive sensor member and/or at least one heater member for automotive vehicle application. The self-standing sandwich structure includes an upper protective layer that is attached, for manufacturing and storage purposes, to a carrier film member of sufficiently low surface energy for enabling separating the carrier film member and the upper protective layer in a non-destructive manner, a lower protective layer, a bottom adhesive layer that is attached to the lower protective layer, and at least an upper electrically conductive layer arranged between the upper protective layer and the lower protective layer.

Abstract: Examples relate to a display control apparatus for a display, to a computing device with an integrated display and a display control apparatus, a processing unit for a computing device with an integrated display and to corresponding methods and computer programs. The display control apparatus comprises interface circuitry and processing circuitry. The processing circuitry is configured to obtain, via the interface circuitry, information on a user of the display, the information on the user indicating a presence of the user relative to the display or an engagement of the user with the display. The processing circuitry is configured to control, based on the information on the user, a display mode of the display, the display mode affecting at least one of a refresh rate and a backlight of the display.

Abstract: A ground fault detection device connected to a high-voltage battery and a positive electrode side Y capacitor includes a detection capacitor operating as a flying capacitor and a discharge circuit including at least a fifth switch. A one end of the discharge circuit is connected to a first circuit that connects a positive electrode side of the high-voltage battery and a one end of the detection capacitor. An another end of the discharge circuit is connected to a second circuit that connects an another end of the detection capacitor and a ground.

Abstract: A wireless accessory has one or more sensors positioned at an outer periphery of its housing, thereby forming a knob-like input. The sensors may be configured to detect a change in contact force or contact location of first and second fingertips at respective first and second opposite sides of the periphery. An input gesture is determined based on the detected change, and a command corresponding to the gesture may be executed.

Abstract: Disclosed are sensing systems and methods that eliminate CPU intervention or interrupts when performing sensor scans of a touch interface, supports low power sensing operation without requiring periodic wake up of the CPU, and is scalable to multi-channel or multi-chip sensor configuration to support large touch screens or a high number of sensors. A sensor scanning module may operate in a chained-scan using direct memory access (CS-DMA) mode or an autonomous scan-multiple scan (AS-MS) mode to perform scanning of all sensors within a frame without requiring CPU intervention or generating CPU interrupts after every scan in the frame. The sensor scanning module may operate autonomously in a low-power always-on scan (LP-AOS) mode for multiple frames without CPU interaction until a touch event is detected. The CPU may operate in a low power sleep mode during the scan while providing consistent refresh rate and low touch-to-system wake up latency.

Abstract: A capacitive sensor includes a switching capacitor circuit, a comparator, and a charge dissipation circuit. The switching capacitor circuit reciprocally couples a sensing capacitor in series with a modulation capacitor during a first switching phase and discharges the sensing capacitor during a second switching phase. The comparator is coupled to compare a voltage potential on the modulation capacitor to a reference and to generate a modulation signal in response. The charge dissipation circuit is coupled to the modulation capacitor to selectively discharge the modulation capacitor in response to the modulation signal.

Abstract: Capacitive sensors and capacitive sensing data integration for plasma chamber condition monitoring are described. In an example, a plasma chamber monitoring system includes a plurality of capacitive sensors, a capacitance digital converter, and an applied process server coupled to the capacitance digital converter, the applied process server including a system software. The capacitance digital converter includes an isolation interface coupled to the plurality of capacitive sensors, a power supply coupled to the isolation interface, a field-programmable gate-array firmware coupled to the isolation interface, and an application-specific integrated circuit coupled to the field-programmable gate-array firmware.

Abstract: Methods, systems, and devices for detection of a protective cover film on a capacitive touch screen are described. A device may include a capacitive touch screen having a surface and a sensor grid underneath the surface having a set of conductive columns and a set of conductive rows. The device may measure a mutual capacitance between a subset of conductive columns or a subset of conductive rows associated with a sensor grid, and compare the measured mutual capacitance between the subset of conductive columns or the subset of conductive rows to a baseline mutual capacitance associated with the set of conductive columns and the set of conductive rows. According to the comparison, the device may determine a presence of a protective layer in contact with the surface of the capacitive touch screen, and adjust an operating characteristic of the sensor grid.

Abstract: A window panel for a display device includes a window substrate which includes a transmissive area which transmits an image displayed on a display panel and a non-transmissive area disposed at a periphery of the transmissive area, a first print layer disposed on a first side of the window substrate in the non-transmissive area, and which forms a boundary line between the transmissive area and the non-transmissive area, and a second print layer disposed on the first print layer in the non-transmissive area. The non-transmissive area includes a first non-transmissive area adjacent to the transmissive area and a second non-transmissive area adjacent to an edge of the window substrate, and side surfaces of the first and second print layers form an inclined surface which has an inclination angle that is smaller than a right angle with respect to the first side of the window substrate in the first non-transmissive area.

Abstract: A capacitive sensor includes: a substrate that is in the form of a sheet; and a sensor electrode that is capacitive and disposed on a frontside of the substrate. The sensor electrode is a conductive fabric made by applying a metal plating on a mesh fabric that is woven of a plurality of warps and a plurality of wefts and that has openings each formed by two adjacent warps among the plurality of warps and two adjacent wefts among the plurality of wefts. An area defined by a maximum outside diameter of a warp or weft is smaller than an area of an opening space of each of the openings.

Abstract: A circuit, system, and method for measuring or detecting pressure or force of a fingerprint on an array of electrodes is described. Pressure or force may be measured or detected using a processed image of the fingerprint, or by measurement of capacitance of deformed variable capacitors.

Abstract: Circuitry for testing an integrated capacitor that includes a first capacitor, a supply node for connecting to a voltage supply, a test node for connecting to the integrated capacitor, and a charge monitoring circuit. The circuitry is operable in a sequence of states including a first state in which the first capacitor is connected to the supply node and is disconnected from the test node so as to charge the first capacitor to a test voltage and a second state in which the first capacitor is disconnected from the supply node and is connected to the test node to apply the test voltage to the integrated capacitor. The charge monitoring circuit is configured to monitor a charge transfer from the first capacitor to the integrated capacitor in said second state and to generate a measurement value based on an amount of the charge transfer.

Abstract: The embodiments of the present disclosure relate generally to systems and methods for canceling mutual capacitive effects in a capacitive touch measurement, and more specifically, implementing a driven shield using rail-to-rail voltage.

Abstract: A touch sensor having a visible area and a peripheral area on at least one side of the visible area includes a substrate, a metal nanowire layer, and a metal layer. The metal nanowire layer is disposed on the substrate and has a first portion corresponding to the visible area and a second portion corresponding to the peripheral area. The metal layer is disposed on the substrate and corresponding to the peripheral area, in which a portion of the metal layer overlaps and contacts at least a portion of the second portion of the metal nanowire layer, such that an overlapping region is formed, a contact area of the overlapping region is between 0.09 mm2 and 1.20 mm2, and a contact impedance of the overlapping region is less than 50?.

Abstract: The present invention provides an adaptively modulated multi-state inverter system, comprising: a split capacitor, four bridge arms and an isolation switch group, on each of the four bridge arms a pair of complementary power switch groups is arranged; the isolation switch group comprises four fuses and six bidirectional thyristors. The output branches of the first bridge arm, the second bridge arm and the third bridge arm are respectively connected in series with a fuse to output a three-phase voltage, and at three-phase output voltage side two shared auxiliary branches are arranged, one auxiliary branch starts from the fourth bridge arm output branch on which a fuse is connected in series and is then connected to the output terminal of the three-phase voltage via three bidirectional thyristors.

Abstract: A capacitive touch sensing device, with: (i) a logical array of capacitive buttons have a number R of rows and a number C of columns; (ii) a first node coupled to a first column in the number C of columns, the first node for receiving a first transmit voltage; (iii) a second node coupled to a second column in the number C of columns, the second node for receiving a second transmit voltage; (iv) a number of intermediate nodes between the first node and the second node, wherein each intermediate node is coupled to a respective column in the number C of columns; and (v) circuitry for applying a respective different voltage to each of the intermediate nodes in response to the first transmit voltage and the second transmit voltage.

Abstract: A sensor includes a base member and a sensor sheet. The sensor sheet includes a film sheet, a plurality of sensor electrodes laid on the film sheet, a plurality of wiring lines laid on the film sheet to conduct electricity to the plurality of sensor electrodes, and a detection part and a tail part. The detection part is held on the base member and includes the plurality of sensor electrodes. The tail part extends from the detection part in a manner so as to face a bottom surface of the base member and includes the plurality of wiring lines. The tail part includes a bent portion bent on a bottom surface periphery of the base member toward the bottom surface of the base member. The plurality of wiring lines extending through the bent portion are laid on an outer bent surface of the bent portion.

Abstract: A successive approximation analog-to-digital with an input for receiving an input analog voltage, and an amplifier with a first set of electrical attributes in a sample phase and a second set of electrical attributes, differing from the first set of electrical attributes, in a conversion phase.

Abstract: A capacitive touch device and a gesture recognition method thereof, a chip and a storage medium are provided. In some embodiments, the gesture recognition method includes: sampling a capacitance of a capacitive sensor in the capacitive touch device to acquire a capacitance sampling value corresponding to a current sampling frame; determining a first capacitance value of an interference capacitance caused by a liquid on the capacitive sensor according to the capacitance sampling value and reference information corresponding to the current sampling frame; determining a touch state of the capacitive sensor represented by the current sampling frame according to the capacitance sampling value and the first capacitance value of the interference capacitance corresponding to the current sampling frame; and recognizing a gesture of a user on the capacitive touch device according to timing information of the touch state represented by the current sampling frame and a historical touch state of the capacitive sensor.

Abstract: A touch sensor and an electronic device are provided, and the touch sensor includes a film substrate and a plurality of touch electrode regions on the film substrate. The plurality of touch electrode regions are spaced apart from each other by at least one gap region, and the touch sensor is bendable along the gap region. The touch sensor is bendable and is not easily damaged, which helps to achieve foldable touch control.

Abstract: A radio frequency (RF) transmitter including a switched-capacitor digital-to-analog converter (SC-DAC) configured to selectively generate a first RF output signal having a first output power control range or a second RF output signal having a second output power control range from input signals received through a plurality of lines may be provided.

Abstract: A solid state switch (SSS) monitoring system of an electronic device includes a SSS sensing component that is electrically coupled to a solid state switch. The SSS sensing component periodically generates a clocked pulse that polls the solid state switch. The SSS sensing component determines whether an electrical characteristic of an output of the solid state switch indicates that the solid state switch is actuated. The SSS sensing component generates a switch state signal to indicate a corresponding one of an actuated and an unactuated state of the solid state switch. A controller is communicatively coupled to the SSS sensing component. The controller restarts the SSS sensing component in response to determining that the SSS sensing component is in an inoperative state.

Abstract: A system for analyzing a state of a thermoset material is disclosed. In various embodiments, the system includes a source of electromagnetic energy configured to expose a sample of the thermoset material to an electric field; a detector configured to determine at least one of a dielectric permittivity or a complex admittance of the sample over a range of frequencies in response to a frequency sweep over the electric field; and an analyzer configured to assess the state of the thermoset material by comparing the at least one of the dielectric permittivity or the complex admittance of the sample against an acceptability map. In various embodiments, the acceptability map comprises a series of acceptability bands that represent a decrease in effective relaxation time from a baseline fresh batch of the thermoset material.

Abstract: This application is directed to detecting touch events on a touch sensing surface coupled to a capacitive sense array and one or more force electrodes. The capacitive sense array includes a plurality of sense electrodes configured to provide a plurality of capacitive sense signals. The force electrodes are configured to provide one or more force signals. A subset of sense electrodes are determined to be associated with a candidate touch based on the capacitive sense signals and their associated baseline values. When force associated with the force signals is below a predetermined force threshold, the candidate touch is determined as an invalid touch (e.g., coverage by a water drop on an area of the touch sensing surface corresponding to the subset of sense electrodes). Baseline values are adjusted for the subset of sense electrodes for determining subsequent touch events associated with the subset of sense electrodes.

Abstract: A circuit portion for indicating a mutual capacitance between a first and second node is provided. The circuit portion comprises a switchable constant current source arrangement configured to supply a first current to the first node in a first direction or a second current to the first node in a second, opposite direction; a variable voltage source configured to output a voltage to the second node so as to hold the first node at a reference voltage; and a comparator arrangement configured to switch between said first and second directions of the constant current source when the voltage output by the variable voltage source reaches a lower threshold voltage or an upper threshold voltage and to output a signal in synchrony with said constant current direction switching. The signal is indicative of the mutual capacitance between the first and second nodes.

Abstract: A touch panel includes a substrate, scan lines, data lines, sub-pixels, a first conductive line, a second conductive line, and a conductive layer. The sub-pixels are arranged in columns along a first direction and arranged in rows along a second direction. Each of the sub-pixels includes an active element and a pixel electrode electrically connected with the active element. The active element is electrically connected with a corresponding scan line and a corresponding data line. The conductive layer overlaps the sub-pixels. The conductive layer includes a first electrode and a second electrode. The first electrode is electrically connected with the first conductive line. The second electrode is electrically connected with the second conductive line. The second electrode is separated from the first electrode. One of the first electrode and the second electrode is a touch electrode, and another one is a common electrode.

Abstract: A test apparatus includes an electrical connection unit electrically connected to respective terminal of each of a plurality of LEDs to be tested, a light source unit which collectively irradiates the plurality of LEDs with light, a measuring unit which measures a photoelectric signal that each of the plurality of LEDs outputs via the electrical connection unit after photoelectrically converting the light with which the light source unit irradiates the plurality of LEDs, and a determination unit which determines pass or fail of each of the plurality of LEDs based on the measurement results by the measuring unit.

Abstract: Provided are a crack detection system and a crack detection method that distinguish between a case where a crack is generated in a structure and other cases not to bring about erroneous detection. In a sensor terminal that detects, from a crack generated in a transducer provided on a structure, a crack in the structure, the transducer having a three-layered structure of conductor-insulator-conductor, the crack detection system including: an impedance measurement unit that measures impedance between the two conductors of the transducer; and a crack detection processing unit that calculates, from a frequency characteristic of the impedance, periodicity data regarding periodicity of a frequency at which impedance becomes a peak, and detects a presence of a crack in the structure in a case of periodicity data different from initially-measured periodicity data being included.

Abstract: To simplify the structure of a holding fixture which holds the shape of the aircraft panel and conveys the aircraft panel, an object is to ensure shape accuracy required in the manufacturing process and hold an aircraft panel in an appropriate shape, in combination with a holding fixture. A shape holding fixture includes: a plurality of support units configured to be positioned on a lower surface side of an aircraft panel, and provided at intervals along a one-axis direction, the aircraft panel being held by a holding fixture configured to grip an edge portion of the aircraft panel; and a shape holding unit provided to each of the plurality of support units, including a rod which supports the aircraft panel from the lower surface side of the aircraft panel, and configured to adjust a position where the rod comes into contact with the aircraft panel to support the aircraft panel, corresponding to the shape of the aircraft panel.

Abstract: An apparatus and method for testing a circuit board included in a battery management system. The circuit board includes a first test point connected in common to one end of a first resistor, one end of a first capacitor and one end of a second resistor; a second test point connected in common to the other end of the second resistor and one end of a second capacitor; a third test point connected to the other end of the first resistor; and a fourth test point connected in common to the other end of the first capacitor and the other end of the second capacitor. The apparatus determines an open-circuit fault of at least one of the first capacitor and the second capacitor based on a first diagnosis voltage between the first and fourth test points and a second diagnosis voltage between the second and fourth test points.

Abstract: A method for introducing electric conductors into an overmolding of a steering wheel frame is provided. The electric conductors are used for heating and shielding purposes and for sensing contact on a steering wheel. In a first step, at least one cut is introduced into the overmolding using a cutting tool. In a second step, both a first layer of an electric conductor and a second layer of an electric conductor are simultaneously introduced into the cut that has been created. The first layer forms both a heating layer for heating the steering wheel and a guard layer which, together with the second layer acting as a sensor layer, allows the capacitive sensing of hand contact.

Abstract: Examples relate to a display control apparatus for a display, to a computing device with an integrated display and a display control apparatus, a processing unit for a computing device with an integrated display and to corresponding methods and computer programs. The display control apparatus comprises interface circuitry and processing circuitry. The processing circuitry is configured to obtain, via the interface circuitry, information on a user of the display, the information on the user indicating a presence of the user relative to the display or an engagement of the user with the display. The processing circuitry is configured to control, based on the information on the user, a display mode of the display, the display mode affecting at least one of a refresh rate and a backlight of the display.

Abstract: The temperature-dependent resistance of a MEMS structure is compared with an effective resistance of a switched CMOS capacitive element to implement a high performance temperature sensor.

Abstract: A touch sensor, includes: a plurality of sensing rows, each of the plurality of sensing rows including first sensing electrodes connected in a first direction; and a plurality of sensing columns, each of the plurality of sensing columns including second sensing electrodes connected in a second direction crossing the first direction; first protrusions disposed at the first sensing electrodes, the first protrusions protruding toward an adjacent second sensing electrode; and first recesses disposed at the second sensing electrodes, the first recesses facing the first protrusions disposed at an adjacent first sensing electrode, wherein the first recesses have a shape corresponding to a shape of the first protrusions.

Abstract: Devices, systems and methods for process monitoring are presented. For instance, the device includes a crystal and a reactance sensor. The crystal is connected to a frequency measurement circuit. The reactance sensor is connected to the crystal. The reactance sensor is configured to detect a change in a process parameter. The frequency measurement circuit detects the change in the process parameter as a change in the frequency of the crystal. In another example, the system includes a reactance sensor and a measurement device. The reactance sensor is disposed in a process chamber, and has a variable reactance responsive to a change in a process parameter. The measurement device is disposed outside the process chamber and has a frequency measurement circuit. The frequency measurement circuit includes a crystal and is connected to the reactance sensor, and detects the change in the process parameter as a change in the frequency of the crystal.