317 results about "Capacitive measurement" patented technology

The invention relates to the field of motor health management and predictive maintenance, in particular to a motor stator winding insulation state evaluation method and system based on a digital model. Comprising the following steps: S1, collecting high frequency of a motor stator winding, and generating multi-physical-quantity real-time data; s2, calculating a dynamic capacitance reference value according to real-time data of multiple physical quantities; s3, performing subtraction operation on the high-frequency equivalent capacitance measurement value and the dynamic capacitance reference value, and extracting an insulation degradation residual signal; s4, constructing a self-adaptive dynamic detection threshold according to multi-physical-quantity real-time data; s5, judging whether the absolute value of the insulation degradation residual signal is greater than a self-adaptive dynamic detection threshold or not: if so, judging that an insulation degradation event occurs; if not, judging that the operation state is a normal operation state; and S6, in response to the insulation degradation event, updating the insulation degradation index, and generating insulation state evaluation based on the updated insulation degradation index. According to the invention, false alarm under severe load fluctuation is avoided, and the accuracy and reliability of evaluation are significantly improved.

The invention discloses an insulation resistance and capacitance measuring circuit and method based on monopulse double-edge analysis, and relates to the related field of the electrical insulation online monitoring technology, and the circuit comprises a detected object and an insulation detection circuit. The insulation detection circuit comprises a controlled pulse voltage source, a coupling resistance network, a current sensor, a switch control module, a signal modulation circuit and a processor. The measurement method implemented based on the circuit comprises the following steps: injecting a common-mode voltage pulse into a transmission line of the power transmission system by adopting a pulse transmitter; pulse current response is collected in real time, a current oscillogram is drawn, and a three-point sampling method is introduced to record a current value for insulation impedance parameter calculation; according to a load condition, a double-edge verification method is applied based on a pulse current attenuation characteristic, and insulation impedance parameters including a resistive component and a capacitive component are independently calculated by analyzing a pulse current rising edge and a pulse current falling edge. According to the invention, non-intrusive synchronous monitoring of resistive and capacitive components of line-to-ground impedance is realized, and the detection precision is improved.

A refillable liquid tip or cartridge for a vaping device includes a capacitive sensor plate located in a tip liquid reservoir. The liquid refilling device provides the liquid sucked from the refilling bottle to the vapour device; the refilling device comprises a capacitance measuring circuit; a microcontroller uses data from the capacitance measurement circuit to determine whether a liquid level in the tip liquid reservoir is above or below a threshold level, if below, activates a liquid pump in the refill device to draw liquid from the refill vial, and if not, activates a liquid pump in the refill device to discharge liquid from the refill vial. And pumping the liquid through the vapour device and up into the tip liquid reservoir. The pumping is stopped once the liquid reaches the threshold level.

The invention relates to a circuit arrangement (1) for multi-zone heating operation, comprising: a plurality of heating wires (2, 2 '), which can be supplied in parallel by a heating voltage, for heating a touch surface (19) comprising a plurality of zones (20, 20'); wherein a respective heating wire (2, 2 ') is associated with a zone (20, 20'); at least one first switching element (3a, 3a ') for each heating wire (2, 2'), which is coupled between the heating wire (2, 2 ') and one of the two different heating potentials (VH +, VH-) of the heating voltage in such a way that, in a heating mode, a heating current is applied to the respective heating wire (2, 2') in the conducting state of the first switching element (3a, 3a '), and interrupting the heating current in the OFF state of the first switching element (3a, 3a '); a control circuit (12, 6a, 6a ', 6b, 6b') configured to generate, for each heating wire (2, 2 '), individual pulse width modulated first control signals (ST1, ST1') to switch the first switching elements (3a, 3a ') between an on state and an off state, respectively, the individual pulse width modulated first control signals being applied to first control terminals (Ga, G'a) of the first switching elements (3a, 3a'), respectively; wherein the control circuits (12, 6a, 6a ', 6b, 6b') are further designed to apply a respective associated heating current to a plurality of heating wires (2, 2 ') in a common heating stage in parallel, in an overlapping manner and / or in an alternating manner, and wherein at least two of the first control signals (ST1, ST1') differ in terms of their duty cycles.

A capacitance measurement circuit includes an analog front-end (AFE) circuit with current mirror circuits, a parasitic capacitor, an AD converter, an output shift register, and a controller. The controller disconnects a capacitor to be measured and connects one current mirror circuit to record an AFE output voltage VN collected at an inverting input terminal of the AD converter, then connects the capacitor to be measured to collect an AFE output voltage VP at a non-inverting input terminal of the AD converter, and converts a value of (VP−VN) into a first digital signal; determines, based on the value of the first digital signal, a connection number m of the current mirror circuits, controls the analog front-end circuit to connect m current mirror circuits, and repeat the steps to obtain a second digital signal; and shift the second digital signal based on the connection number m to obtain a capacitance measurement value.

The invention relates to the technical field of flexible electronics and sensing, in particular to a capacitive flexible pressure sensor based on a barium titanate composite dielectric layer, which sequentially comprises a lower electrode layer, an upper electrode layer, a lower electrode layer and an upper electrode layer from bottom to top, the composite dielectric layer is arranged on the lower electrode layer and is formed by compounding an elastic polymer matrix and a high-dielectric-constant barium titanate (BaTiO3) filler; the upper electrode layer is made of a flexible conductive material and is arranged on the composite dielectric layer; the lower electrode layer and the upper electrode layer are connected with an external capacitance measuring circuit through wires. According to the sensor disclosed by the invention, the comprehensive performance of high sensitivity, wide detection range, low hysteresis and excellent cycle stability is realized by optimizing the shape of the barium titanate filler, surface modification and composite structure design.

The invention provides an excitation amplitude automatic closed-loop control system and method for a DLCP test. The system comprises a multi-frequency alternating current excitation and direct current bias voltage applying module which is used for automatically applying alternating current excitation signals and direct current bias voltage signals according to a preset excitation amplitude sequence under a plurality of test frequencies; the PID closed-loop control module is used for performing closed-loop correction on the applied voltage according to the response of the test port of the tested semiconductor device, so that the condition of the applied voltage at the test port meets a preset requirement; the capacitance measurement module is used for acquiring an equivalent capacitance response signal of the tested semiconductor device; the capacitance test data caching module is used for performing associated marking and classified caching on the capacitance test data according to the test frequency, the excitation level and the bias voltage set point; and the main control module is used for coordinating automatic test processes under the conditions of a plurality of test frequencies and different excitation amplitudes and outputting corresponding capacitance test data so as to improve the consistency, stability and automation degree of the DLCP test.

The invention relates to the technical field of semiconductor device measurement, and provides a semiconductor nonlinear output junction capacitance measurement method based on fitting iteration, and the method comprises the steps: firstly building a junction capacitance extraction circuit, collecting the turn-off transient waveform of a to-be-measured device through a test platform, extracting the oscillation frequency fexp through fast Fourier transform, and carrying out the measurement of the to-be-measured device; based on the relation between the oscillation frequency and the junction capacitance and parasitic parameters, the initial junction capacitance Coss is reversely deduced; then, fitting is carried out by adopting a hyperbolic tangent function, fitting parameters are optimized through a least square method, a preliminary junction capacitance Coss-test voltage udc relation curve under different voltage grades is obtained, an oscillation frequency simulation circuit is further built, simulation frequency fm is obtained, fm is compared with fexp, if deviation exists, the fitting curve is adjusted and iterative optimization is carried out, and the test voltage udc relation curve of the junction capacitance under different voltage grades is obtained. And ending until the error of two adjacent rounds of fitting results is lower than a set error threshold value, thereby obtaining a final accurate junction capacitance Coss-test voltage udc relation curve.

Embodiments of the present disclosure relate to an electronic device for determining an active state of a touch sensor comprising a capacitance measurement circuit to be coupled to the touch sensor, the touch sensor comprising a first electrode and a second electrode, the capacitance measurement circuit is configured to obtain a first measurement based on a self-capacitance of the first electrode and a second measurement based on a mutual capacitance between the first and second electrodes. The algorithm module is configured to apply an algorithm to the first and second measurements, thereby generating a result signal. The threshold comparator is configured to compare the result signal to a threshold and to generate a comparison signal having a first comparison value if the result signal is greater than the threshold and to generate a comparison signal having a second comparison value if the result signal is less than the threshold. The output module is configured to provide an output signal based on the comparison signal, wherein the output signal is indicative of an activation state of the touch sensor.

A capacitance measurement circuit includes a charge to voltage converter (CVC) that includes at least one first variable capacitor, an excitation signal generation circuit, a differential amplifier, a first switch circuit, and at least one second variable capacitor, wherein a parasitic capacitance from a sensing capacitance sensed by a capacitance sensor is reduced by the at least one first variable capacitor. The excitation signal generation circuit is arranged to generate and connect a first excitation signal to the capacitance sensor, and generate and connect a second excitation signal to the at least one first variable capacitor, wherein the first excitation signal and the second excitation signal are out-of-phase, and a voltage amplitude of the first excitation signal is different from a voltage amplitude of the second excitation signal. The inverting input terminal of the differential amplifier is arranged to receive the sensing capacitance from the capacitance sensor.

The invention belongs to the technical field of nuclear power, and particularly relates to a ground capacitance measurement method based on series capacitance and high-frequency signal injection. In order to solve the problem that a traditional signal injection method cannot accurately calculate the ground capacitance level of a power distribution network, the invention provides a ground capacitance measurement method based on a series capacitor and high-frequency signal injection. The leakage inductance of the voltage transformer is accurately measured by injecting the high-frequency signal, so that a resonance point is convenient to find during frequency sweeping, and the resonance point measured during frequency sweeping is more accurate.

In a steering wheel unit, when any one of electrostatic capacitances measured by a capacitance measurer while a self capacitance detection mode is set by a mode switcher is equal to or larger than a first threshold value, it is determined that the operator's hand is in contact with a rim at a position that overlaps at least one of electrodes. When the electrostatic capacitance is equal to or larger than a second threshold value, which is smaller than a first threshold value, and smaller than the first threshold value, the mode is switched to the mutual capacitance detection mode. After the switching, when an electrostatic capacitance newly measured in the mutual capacitance detection mode is equal to or larger than a third threshold value, it is determined that the operator's hand is in contact with the rim at a position that overlaps a gap between the electrodes.

A measuring system for characterizing a multilayered structure with layer-by-layer different ohmic properties, having a sensor module, an electrical switching device, and a measuring electronics unit. The sensor module has more than two planar coils arranged in a stack, and the electrical switching device is contacted with the planar coils and is configured to connect these coils to the measuring electronics unit such that the coils are switchable between a measuring configuration and a reference configuration. In the measuring configuration, the planar coils at least partially form an optionally inductive or capacitive measuring sensor, with the detection area extending outside the sensor module for determining a property of a low and / or high-resistance layer of the structure. In the reference configuration, the planar coils at least partially form an optionally inductive or capacitive reference sensor, with the detection area extending essentially inside the sensor module for determining a sensor module property.

The invention provides a resistor and capacitor measuring circuit and method, and relates to the technical field of resistor and capacitor measurement, and the resistor and capacitor measuring circuit comprises a switch S1, a switch S2, a switch S3, a switch S4, a switch S5, a switch S6, a reference capacitor CREF, a capacitor CTEST to be measured, a reference resistor RREF, a resistor RTEST to be measured, a Schmitt trigger u1, a time-to-digital converter TDC and a microprocessor muC. And the Schmitt trigger u1, the time-to-digital converter TDC and the microprocessor muC are sequentially connected in series. According to the resistor-capacitor measuring circuit and method, the discharge time of the reference resistor-capacitor and the discharge time of the resistor-capacitor to be measured are respectively measured through the time-to-digital converter, the time proportion is calculated, and the parameters of the resistor-capacitor to be measured and the resistor-capacitor to be measured are calculated and reversely deduced by combining the known reference capacitor and the resistor. The correction compensation amount is obtained through an additional measurement state, and then the measurement result is corrected, so that the influence of the conduction loss of the switch on the measurement result is greatly reduced.

The invention discloses a low-temperature safety valve leakage detection device based on electrical capacitance tomography, which comprises a liquid nitrogen storage container, a test container, a low-temperature stop valve, a detected low-temperature safety valve, a constant-temperature water bath device, a flow meter, a water tank, a leakage detection pipeline, a capacitance measurement system and a data acquisition and software system, the capacitance measuring system comprises a plurality of groups of copper electrode plates and a processing module, each group of copper electrode plates comprises two copper electrode plates arranged on two opposite side parts of the water tank, and the copper electrode plates are used for capturing bubbles formed by the low-temperature gas in the cavity and acquiring capacitance signals; and the copper electrode plate is electrically connected with the data acquisition and software system through the lead electrode plate connector and the shielding coaxial cable. Insulation supports are arranged between the water tank and the copper electrode plates, the interior of the water tank is divided into a plurality of cavities, and communication gaps are formed between the adjacent cavities. The invention further discloses a low-temperature safety valve leakage detection method based on electrical capacitance tomography. According to the method, the accuracy and comprehensiveness of calculating the leakage rate of the low-temperature gas are improved.

Systems and methods are provided herein for determining the planarity of a semiconductor wafer. The systems and methods described herein utilize a capacitive measurement tool to detect and characterize the bow of a semiconductor wafer. The capacitive measurement tool disclosed herein utilizes a non-contact, capacitive sensor unit to measure wafer bow. Unlike conventional capacitive sensing techniques used to measure wafer bow, the capacitive sensor unit disclosed herein uses a plurality of electrodes for simultaneously obtaining a plurality of capacitance measurements from the wafer at various locations on the wafer surface. By including a plurality of electrodes within the capacitive sensor unit, the techniques described herein increase the amount of data collected across the wafer surface at any given time to improve the throughput and measurement accuracy of the capacitive measurement tool.

The application discloses a self-adaptive capacitive liquid level sensor, which comprises a metal cylinder, a PCB circuit board, a reference electrode and a measuring electrode which are arranged on the PCB circuit board and are insulated from each other, the reference electrode is arranged at the bottom end of the PCB circuit board and is used for forming a reference capacitor with the metal cylinder, the measuring electrode is arranged above the reference electrode and is used for forming a measuring capacitor with the metal cylinder, and a controller is arranged for calculating the liquid level height after compensating the measuring capacitor by the reference capacitor. The capacitive liquid level sensor is provided with the reference electrode and the corresponding algorithm steps, so that the calculation of the liquid level height is irrelevant to the dielectric constant of the medium, thereby avoiding the detection error caused by the change of the dielectric constant, and the sensor can be applicable to the liquid level detection of different oil products in different environments.

A capacitance measuring circuit includes a charge-to-voltage converter including at least one first variable capacitor, an excitation signal generating circuit, a differential circuit, a first switching circuit, and at least one second variable capacitor. Wherein a parasitic capacitance value in a sensing capacitance value sensed by a capacitance sensor is reduced by at least one first variable capacitance. The excitation signal generating circuit is used for generating and connecting a first excitation signal to the capacitive sensor and generating and connecting a second excitation signal to the at least one first variable capacitor, the first excitation signal and the second excitation signal are opposite in phase, and the voltage amplitude of the first excitation signal is different from that of the second excitation signal. The inverted input end of the differential amplifier is used for receiving a sensing capacitance value from the capacitance sensor.

The invention relates to a circuit board backdrill capacitance testing method, device and equipment and a storage medium, and the method comprises the steps: obtaining a capacitance detection instruction, and obtaining the image information of a to-be-detected circuit board according to the capacitance detection instruction; carrying out clustering analysis on the image information of the to-be-detected circuit board by adopting a k-means algorithm to obtain a feature image of the to-be-detected circuit board, and carrying out analysis according to the feature image to obtain a displacement distance and an angle of the probe; adjusting the position of the probe according to the displacement distance and the angle of the probe, and generating a capacitance measurement message after the adjustment of the probe is completed; according to the capacitance measurement message, calculating a capacitance value of the circuit board to be detected through a capacitance method, and comparing the capacitance value of the circuit board to be detected with a preset capacitance value to obtain a capacitance comparison result; and generating a quality evaluation result of the back drilling hole of the circuit board according to the capacitance comparison result, and transmitting the quality evaluation result of the back drilling hole of the circuit board to the user side. The method has the effect of improving the precision and efficiency of back drilling hole quality detection.

The invention discloses a machine learning icing recognition system and method for a skymirror system, and relates to the technical field of measurement, and the method comprises the following steps: S1, transmitting an optical signal to an ice layer, and judging the type of the ice layer based on the features of the returned optical signal; s2, acquiring an ice layer capacitance value, and calculating the thickness of the ice layer according to the capacitance value; s3, acquiring an image containing a water body, a sensitive zone at the junction of the water and the ice layer and the ice layer, and calculating the thickness of the sensitive zone according to image features and optical signal features; s4, acquiring the signal-to-noise ratio of the capacitance measurement data, determining a first weight coefficient according to the signal-to-noise ratio, and determining a second weight coefficient according to the contrast ratio of the image; and S5, performing weighted fusion on the capacitance measurement thickness and the image thickness based on the first weight coefficient and the second weight coefficient to obtain the corrected ice layer thickness. According to the invention, through multi-sensor data fusion, weight dynamic distribution and construction of prediction modeling, the problems of ice type identification, thickness measurement and growth law prediction are solved.

The wearable electronic device may be equipped with sensors to measure heart rate, blood oxygen levels, respiratory rate, blood pressure, blood glucose levels, and skin temperature. The device may include graphene-based sensors to measure heart rate, blood oxygen levels, respiratory rate, blood pressure, blood glucose levels, and skin temperature. The device may include a process that uses capacitive measurements to determine reliability of biosensor measurements. Capacitive measurements may be made on the device and a quality of contact between the device and the wearer may be determined. When the quality of contact between the device and its wearer is insufficient for reliable biosensor measurements, the device may display an alert to the wearer.

The invention discloses a capacitor health degree detection method and equipment, and the method comprises the steps: applying a sine wave test signal to a to-be-detected capacitor, obtaining a current signal and a voltage signal of the to-be-detected capacitor, calculating the phase angle of the to-be-detected capacitor through the current signal and the voltage signal, calculating the equivalent series resistance and capacitive reactance of the to-be-detected capacitor based on the phase angle, and obtaining the health degree of the to-be-detected capacitor. And calculating the capacitance of the to-be-measured capacitor based on the capacitive reactance, calculating the loss tangent value of the to-be-measured capacitor according to the equivalent series resistance and the capacitive reactance, and predicting the health degree of the capacitor according to the equivalent series resistance, the capacitance value and the change of the loss tangent value. Therefore, when the capacitor operates normally, current and voltage signals of the capacitor can be measured actively, and the health degree of the capacitor can be calculated by combining the equivalent series resistance, the capacity and the loss tangent value of the capacitor, so that the health condition of the capacitor can be evaluated more accurately and comprehensively, and early warning and troubleshooting can be carried out on the abnormal capacitor as soon as possible.

The invention relates to the technical field of capacitive voltage transformers, in particular to a capacitive voltage transformer and a capacitance variation adjusting system thereof. The adjusting system comprises a capacitance measuring module which is provided with two groups of test electrodes, one group is connected with a high-voltage electrode of a high-voltage capacitor in parallel and obtains a high-voltage capacitance value, and the other group is connected with a low-voltage capacitor electrode in parallel and obtains a low-voltage capacitance value; the processing control module is used for receiving the high-voltage capacitance value and the low-voltage capacitance value, judging whether the ratio of the high-voltage capacitance value to the low-voltage capacitance value exceeds a preset threshold value or not, calculating a capacitance value needing to be compensated when the ratio exceeds the preset threshold value, and generating compensation information according to the capacitance value needing to be compensated; and the compensation intervention module comprises a plurality of compensation capacitors with different capacitance gradients, and is configured to receive the compensation information and connect the specified compensation capacitors in series according to the compensation information. Safe and stable operation of the capacitive voltage dividing assembly is ensured through the gas insulating medium, and the performance and reliability of the capacitive voltage transformer are improved through the adjusting system.

The invention discloses a self-adaptive optical distortion compensation device and compensation method based on high-speed closed-loop control, and the device comprises an optical path front-end interface which is used for connecting a coupling wind tunnel or a laser emission system; the wavefront sensor is used for measuring a local wavefront slope by adopting a distributed array; the FPGA controller comprises a wavefront reconstruction processor and a closed-loop logic controller and is used for reconstructing wavefront and generating a control instruction; the MEMS deformable mirror array comprises a plurality of MEMS drivers and is used for correcting a wavefront phase; the feedback monitoring module is used for performing dual verification through deformation capacitance measurement and CCD image feedback; and the imaging / laser output end is used for converting the corrected optical signal into an image and outputting the image. The method can be widely applied to the fields of high-speed aircraft wind tunnel testing, laser communication, infrared imaging guide head calibration, high-energy laser beam shaping and the like, a programmable hardware platform, a high-speed parallel operation structure and a predictive control algorithm are introduced, and unprecedented sub-microsecond closed-loop compensation is achieved.

The invention relates to a capacitance measurement device and a capacitance measurement method based on the capacitance measurement device. The capacitance measurement device comprises a first voltage source, a second voltage source, a first range resistor, a vector voltage acquisition module and a vector current acquisition module. The first voltage source, the capacitor to be measured and the vector current acquisition module are connected in series to form a first loop; the second voltage source, the first measuring range resistor and the vector current acquisition module are connected in series to form a second loop; the first measuring range resistor is a measuring range resistor with a variable resistance value; the vector voltage acquisition module is connected in parallel with the two ends of the capacitor to be measured. According to the embodiment of the invention, capacitance measurement can be realized, the capacitance measurement accuracy is improved, the capacitance measurement range is expanded, the capacitance measurement efficiency is improved, and the capacitance measurement operation complexity is reduced.

To provide an electrostatic capacitance measuring device capable of reducing floating capacitance generated at a tip part of a probe to measure electrostatic capacitance of a measurement target object at high accuracy.SOLUTION: An electrostatic capacitance measuring device 1 includes: a pair of probes 10 extending in a longitudinal direction and arranged in nearly parallel with each other; an electrostatic capacitance measuring instrument connected to the pair of probes 10; a planar shield plate 20 having a first main surface 20a and a second main surface 20b opposed to each other extending in a direction parallel to an extending direction of the pair of probes 10 and placed so that the first main surface 20a and the second main surface 20b are interposed between the pair of probes 10; and insulating layers 30 each provided in the first main surface 20a and the second main surface 20b of the shield plate 20. In the electrostatic capacitance measuring device 1, when viewed in a direction that the pair of probes 10 overlap with each other, the shield plate 20 is arranged at any position overlapping with the pair of probes 10.SELECTED DRAWING: Figure 1

A capacitance measuring device and capacitance measuring method are configured to batch test the capacitance parameters of chips. The capacitance measuring device includes: a measurement circuit board, including: a test station configured to install the chip to be tested; and a reference capacitor, wherein a first end of the reference capacitor is electrically connected to a first pin of the chip to be tested installed at the test station at a first node, a second end of the reference capacitor is configured to receive a first measurement signal, and a second pin of the chip to be tested installed at the test station is configured to receive a second measurement signal; and an automatic tester is electrically connected to the measurement circuit board and configured to provide the first measurement signal and the second measurement signal, and determine the capacitance parameters of the chip to be tested based on the signal at the first node, wherein the first measurement signal and the second measurement signal are both sine signals or cosine signals, and the phase difference between the first measurement signal and the second measurement signal is (2n+1)π, where n is an integer.

An electromechanical system includes a frame; an element movable relative to the frame, the movable element comprising a membrane and a rigidifying structure for the membrane; a capacitive measurement or actuation device; a first transmission device for a movement between the movable element and the capacitive measurement or actuation device, the first transmission device being rotatably movable relative to the frame by a plurality of first pivot hinges; in which system: a first opening is arranged in the movable element; the frame includes a first island extending into the first opening; and the first transmission device is connected to the first island via one of the first pivot hinges.

The invention discloses a flexible capacitive pressure sensor and a preparation method, and relates to the technical field of flexible capacitive pressure sensors.The flexible capacitive pressure sensor comprises a shell, a second binding post arranged at one end of the shell, a shell cover arranged at the other end of the shell and a first binding post arranged on the shell cover, an upper packaging layer is arranged in the shell, an upper electrode layer is arranged on one side of the upper packaging layer, and a lower electrode layer is arranged on the other side of the upper packaging layer; a middle dielectric layer is arranged on one side of the upper electrode layer, a lower electrode layer is arranged on one side of the middle dielectric layer, and a lower packaging layer is arranged on one side of the lower electrode layer; conductive film structures are arranged between the lower electrode layer and the middle dielectric layer and between the upper electrode layer and the middle dielectric layer; a sealing assembly is arranged in the shell cover; an extrusion assembly is further arranged in the shell cover; by using the sealing assembly, the sealing performance between the shell and the shell cover is improved, external moisture and dust are prevented from entering the shell, the accuracy of capacitance measurement is improved, and the service life of the flexible capacitive pressure sensor is further prolonged.

An analyte in a liquid sample is detected using a capacitive sensor having electrodes and a sensor surface, and a signal processor. The sample is dried to reduce its liquid content, and capacitive measurements are made after the drying and preferably also before the drying. The sample may include particles, and the analyte is part of or attached to the particles, and the particles provide a major part of the capacitance change compared to absence of particles. In another example the particles are degenerative and form an integral mass upon application of heat, enhancing the extent of capacitance change.