Abstract: A sensor includes a substrate, a reference electrode provided above the substrate, a lower electrode provided above the reference electrode via an insulating film, and an upper electrode provided above the lower electrode via a physical quantity detecting film. The upper electrode and the lower electrode form a parallel-plate-type detection capacitor, and the lower electrode and the reference electrode form a parallel-plate-type reference capacitor.

Abstract: Methods and apparatus are disclosed for automated acquisition of moisture readings using a handheld moisture meter. In automated mode, a succession of moisture content readings at successive positions can be acquired without any user interface input, by moving the moisture meter to successive positions on a sample, and holding steady at each position. Moisture readings stable for a time period (e.g. one second) are indicative of moisture content of a sample at a stationary position and are collected. Moisture readings varying in time are indicative of motion of the moisture meter and are not collected. Statistics can be performed on the collected readings. Notifications of stable readings and alerts for out-of-range readings can be provided. Hardware and software architectures are disclosed. The innovative technology is suitable for wood, concrete, and other materials at any stage of manufacturing or product lifecycle.

Abstract: In the case of a strapping apparatus for strapping articles to be packaged with a strapping band, said apparatus having a tensioning device for applying a band tension to a loop of a strapping band, wherein the tensioning device is provided with a tensioning element that is provided to apply a band tension and to engage in the strapping band and is drivable in rotation, and having a connecting device for creating a permanent connection, in particular a welded connection at two regions, located one on top of the other, of the loop of the strapping band, a possibility is intended to be created by way of which damage to articles to be packaged that is attributable to the tensioning operation, and non-uniform applications of tensile stress to a band loop are avoided or at least reduced.

Abstract: Disclosed is a humidity sensing element that includes an insulation section made of an insulating material, an application electrode to which a voltage is applied, and an output electrode which outputs a voltage signal corresponding to an electrical current flowing through an electrical path via water molecules adhering to a surface of the insulating material in response to the voltage applied to the application electrode. A distance between the application electrode and the output electrode is equal to or greater than a predetermined value, and/or a total sum of lengths of portions where the application electrode and the output electrode face each other is less than a predetermined value.

Abstract: Moisture sensors that include a resonant circuit having a capacitive element and an inductive element, wherein the inductive element acts as an antenna; a conditionally conductive polymeric layer, wherein the conditionally conductive polymeric layer has a first level of conductivity when exposed to a first set of moisture conditions and has a second level of conductivity when exposed to a second set of moisture conditions; and an insulative layer disposed between the resonant circuit and the conditionally conductive polymeric layer.

Abstract: A sensor device includes a housing having a hole allowing substances to pass from an exterior of the housing to an interior of the housing, and a printed circuit board having a humidity sensor and at least one electronic component. The sensor device also includes a tube comprising a waterproof material, wherein a first end of the tube surrounds the humidity sensor, wherein a first seal is formed by between the first end of the tube and the printed circuit board, wherein a second end of the tube is located proximate the hole. The sensor device also includes a waterproof, breathable material layer disposed between the second end of the tube and the hole, wherein a second seal is formed between the material layer and the housing, wherein a third seal is formed between the material layer and the second end of the tube. The hole and the material layer allow water vapor to pass from the exterior to the humidity sensor.

Abstract: A method and apparatus for detecting an obstructed surface are provided. The apparatus includes: at least one memory comprising computer executable instructions; and at least one processor configured to read and execute the computer executable instructions. The computer executable instructions cause the at least one processor to: detect a current draw from a generator; determine that a surface including a conductive coating is obstructed in response to the current draw being greater than a predetermined threshold; and output a signal to perform a function in response to determining that the surface is obstructed.

Abstract: An agricultural working machine embodying a combine harvester for processing crop includes an intake conveyor mechanism for picking up the crop, a moisture content sensor arrangement for measuring a moisture content of the picked-up crop and generating a crop moisture signal based on the measured moisture content. A throughput sensor arrangement, preferably a layer thickness sensor arrangement, determines a throughput quantity of the picked-up crop. The crop moisture content signal is corrected on a basis of the throughput quantity that is determined.

Abstract: Disclosed are a sensor for measuring a tilt angle based on electronic textile according to the present invention and a method thereof. A sensor for measuring a tilt angle based on electronic textile according to the present invention includes a plurality of textile electrodes disposed at predetermined uniform intervals on a textile surface; a textile conductive wire of which one end is connected to a center between the plurality of textile electrodes; and a metal bead connected to another end of the textile conductive wire to thereby be connected to the textile surface.

Abstract: The present invention provides a probe block, which comprises 1) a conductive base on which a first groove is formed, 2) a pair of signal transmitting probes which have dielectric covers and are placed parallel to each other in the first groove, and 3) a ground probe which is in contact with the conductive base, wherein front portions of the signal transmitting probes and the ground probe protrude from the conductive base to form signal transmitting probe needles and a ground probe needle, respectively. The probe block of the present invention has excellent high frequency responses characteristics and is easy for maintenance.

Abstract: A moisture meter for determining the moisture content of particulate material is provided. The moisture meter comprises a frame part, a space, a measuring cup disposed within said space for receiving a sample of the particulate material which moisture is to be measured, and moisture measuring means. The moisture meter comprises a swiping means for removing at least partly a part of a sample of particulate material which moisture is to be measured, which part of the sample of particulate material extends out of the inner space of the measuring cup through the open end of the measuring cup. The swiping means are movably attached to the frame part for movement in a swiping path where a swiping member of the swiping means is configured to move essentially along the open end of the measuring cup.

Abstract: A sensor senses a magnitude of a physical parameter of the sensor's environment. The sensor has first and second electrodes, and a material layer between them. The material has an electrical property, e.g., capacitance or resistance, whose value depends on the magnitude of the physical parameter. The first electrode is formed in a first layer, and the second electrode is formed in a second layer, different from the first layer. The first layer has a trench and an elevation next to the trench. The trench has a bottom wall and a side wall. The material is positioned on the bottom wall and on the side wall and on top of the elevation. The trench accommodates at least a part of the second electrode. The second electrode leaves exposed the material formed on top of the elevation.

Abstract: A device for use with a conduit having a first conduit end and a conduit second end, into which conduit a cable can be installed using a flow of air into the first conduit end, the device being suitable for confirming that the air is flowing out from the second conduit end. In an embodiment, the device includes a housing, means to enable connection of the device to the second conduit end, a detector arranged to detect an electrical property change, and an actuator for causing an electrical property change detectable by the detector, wherein in use, the air flowing into the device causes the detector and the actuator to move relative to each other, causing an electrical property change detectable by the detector.

Abstract: An oil-degradation detecting apparatus that can more accurately judge oil degradation and a mechanical system having a rotating part or a sliding part and including the oil-degradation detecting apparatus are provided. Two plates (21, 22) are disposed in an oil flow path (11) so as to be parallel to each other, an ammeter (24) measures a current that flows when an AC voltage is applied between the two plates (21, 22), a voltmeter measures the voltage between the plates (21, 22), and a signal processor (processor) (31) determines the electrical conductivity and the dielectric constant of the oil (10) based on the measurement results from the ammeter (24) and the voltmeter (25) and judges degradation of the oil (10) based on the electrical conductivity and the dielectric constant.

Abstract: A system, controller, and method for detecting moisture on a windshield that uses an isolated electrode coupled to a windshield. The isolated electrode is configured to exhibit an electrical impedance indicative of moisture present on a surface the windshield. The controller is configured to determine an electrode impedance value corresponding to the electrical impedance exhibited by the isolated electrode for detecting moisture on the windshield. By using an isolated electrode, the system is simpler and less expensive than other systems that have at least one electrode providing a return path for another electrode. Also, a way to use the isolated electrode for both detecting moisture on the windshield, and heating the windshield is described.

Abstract: A method for determining the moisture content of wood (1), including the operating steps of inserting the wood (1) between a first plate and a second plate (3) of a capacitor (4); applying a first signal to the first plate (2) of the capacitor (4) using the plate as a transmitting antenna; detecting on the second plate (3) a second signal induced by the first signal, using the second plate (3) as a receiving antenna; determining from the second induced signal detected, a third reference signal, obtaining a differential signal; determining the components of the differential in phase and in quadrature signals from the first signal; filtering the components of the differential in phase and in quadrature signals to obtain a filtered in phase component and a filtered in quadrature component, which are independent of the frequency of the first signal; and calculating the moisture content of wood (1) based on the value of the filtered in phase and in quadrature components of the differential signal.

Abstract: Apparatuses and systems for emulating electrical characteristics of a material having a known dielectric response are disclosed for standardizing and calibrating of electromagnetic devices. The emulator apparatus can include an electrically non-conductive layer having a dielectric constant less than the material dielectric constant and an electrically conductive layer adjacent the non-conductive layer. Artificial dielectrics for emulating the dielectric response of a material are also disclosed including a substrate matrix having a dielectric constant less than the material dielectric constant and an additive combined with the substrate, the additive having a dielectric constant higher than the material dielectric constant.

Abstract: A contact-type object water content sensing device and method and a computer program product are presented. The device includes a power unit, a sensing unit, and an calculating unit. The sensing unit includes a substrate and a copper foil, and the copper foil is configured on the substrate. The sensing unit is used to contact a target object and a power unit is used to supply power to the copper foil. The copper foil when supplied with power forms an equivalent capacitor, and the equivalent capacitor has different capacitances in correspondence to a water content of the target object. The calculating unit is electrically connected to the sensing unit and is used to analyze the capacitance of the equivalent capacitor, so as to calculate the water content of the target object.

Abstract: An advanced landscape irrigation control system that integrates a soil moisture probe with a timer-based controller which can be used to directly control a single irrigation zone without need for a separate timer-based controller. The invention is equally capable of being installed as a soil moisture sensor that operates under the control of a traditional timer-based controller. The moisture probe and system disclosed in this invention is fully buried in the soil and electrically connected to the water solenoid-valve(s), measuring temperature and soil moisture content using a capacitive-based probe in determining water solenoid-valve(s) operation. The device has no user settings and requires no calibration, including determining optimal soil moisture content by a unique method of recognizing soil signatures, or the unique electrical response of soils to water.

Abstract: An apparatus and techniques for determining whether a medical electrode, such as a defibrillation electrode coupled to an automated external defibrillator, is in a condition for replacement. The determination can be made as a function of one or more data. In one exemplary embodiment, the determination is a function of one or more measurements of an impedance of a hydrogel bridge in a test module. In another exemplary embodiment, the determination is a function of one or more environmental condition data from one or more environmental sensors.

Abstract: In a method for capacitive determination of the moisture content in a gas to be measured, it is provided that a capacitive element (2) brought into contact with a gas to be measured is operated in the manner of an RC oscillator (5) in charge-discharge cycles (27, 28), with the moisture content of the gas to be measured being determined from the time duration of a cycle. To assess measurement errors brought about by contaminants or aging effects, a measure for the time duration of a charging process (27) and a discharging process (28) is determined from output signal (26) of RC oscillator (5) and is processed with the measurement signal for the moisture content into a corrected measurement signal.

Abstract: A method of measuring the capacitance of a capacitive component (21), whereby a digital bridge with two measuring branches generates a first signal (B1) defined by a train of measuring pulses (M) having a frequency (f1) related to the unknown capacitance being measured, and a second signal (B2) defined by a train of reference pulses (L) having a frequency (f2) related to a reference capacitance (CREF) of known value. The time difference (?T) between the times (T1, T2) taken by the two measuring branches of the digital bridge to generate an equal number of pulses (Th1, Th2) is calculated. The capacitance difference (?C) between the unknown capacitance and the reference capacitance (CREF) is determined as a function of the time difference (?T). The unknown capacitance of the capacitive component (21) is calculated on the basis of the reference capacitance (CREF) and the capacitance difference (?C).

Abstract: The invention presents an apparatus and techniques for determining whether a medical electrode, such as a defibrillation electrode coupled to an automated external defibrillator, is in a condition for replacement. The determination can be made as a function of one or more data. In one exemplary embodiment, the determination is a function of one or more measurements of an impedance of a hydrogel bridge in a test module. In another exemplary embodiment, the determination is a function of one or more environmental condition data from one or more environmental sensors.

Abstract: A method and system for adjusting characteristics of a relative humidity sensor in order to achieve a desired value of accuracy is presented. A relative humidity sensor charge balance circuit includes a series of sensing capacitors Cx1, Cx2 including a thin porous platinum top plate, a humidity sensitive polyimide dielectric, and two metal bottom plates on a semiconductor substrate; and two fixed oxide capacitances Cref, and C0. Changes in humidity affect the humidity sensitive dielectric thereby causing changes in the sensing capacitive value of the capacitive circuit. The charge in the sensing capacitor and the fixed capacitor C0 can be controlled separately by adjusting and/or trimming the supply voltage using a voltage trimmer; thereby the slope and offset of the relative humidity sensor circuit can be modified and controlled to particular desired values.

Abstract: A moisture meter (1) has an elongate probe (3) supporting at least one pair of electrodes (5, 6), and being configured for insertion into bulk material (C). There is a transmitter (50) for driving an electrode (5, 6) and a detector (51) for receiving current signals of an electrode. A controller (54) controls drive of the electrodes (5, 6) and processes detected signals to provide a moisture reading. There are at least two axially separated radial spacers (7, 8) having ridges (30) extending radially to an extent greater than the electrodes, to centralise the probe and to provide a gap between the electrodes and bulk material when the probe is inserted in a hole (H) in the bulk material. The spacers (7, 8) are configured to provide a low friction fit within a hole in the bulk material. There is a leading spacer (7) on a leading side of a first electrode (5) and a trailing spacer (8) at a trailing side of a second electrode (6).

Abstract: A sensor for measuring the moisture and salinity of a material is disclosed herein. The sensor preferably includes a soil moisture circuit, a soil salinity circuit and a probe structure. The soil moisture circuit includes a high frequency oscillator, a voltage meter and a reference capacitor. The soil salinity circuit includes a low frequency oscillator, a voltage meter and a reference resistor. A third voltage meter allows for voltage outputs to be measured to calculate soil moisture and soil salinity values.

Abstract: A method and system is provided for analyzing a package having components. The package may include electrical or computer components. The method and system uses a computer program to receive inputted data and extract data from files. The computer program also selects the best sub-program to analyze the data to compute the parameters for packaging the components and designing the package, and displays the results of the analysis.

Abstract: A humidity sensor apparatus and method of forming the same. A substrate can be provided upon which a plurality of humidity sensing components are disposed to form a humidity sensor thereof. Each humidity sensing component generally includes an associated particular parasitic capacitance. This parasitic capacitance is utilized to reduce and/or control a sensitivity and a total capacitance value associated with the humidity sensor without increasing a size of the humidity sensor and/or humidity sensor components (e.g., capacitors).

Abstract: Apparatuses and systems for emulating electrical characteristics of a material having a known dielectric constant are disclosed for standardizing and calibrating of electromagnetic devices. The emulator apparatus can include an electrically non-conductive layer having a dielectric constant less than the material dielectric constant and an electrically conductive layer adjacent the non-conductive layer. Artificial dielectrics for emulating the dielectric constant of a material are also disclosed including a substrate matrix having a dielectric constant less than the material dielectric constant and an additive combined with the substrate, the additive having a dielectric constant higher than the material dielectric constant.

Abstract: An improved relative humidity sensor apparatus that provides a more accurate measurement of humidity in the presence of water condensation. A series capacitive sensor includes a thin porous platinum top plate, a humidity sensitive polyimide dielectric, and two metal bottom plates on a semiconductor substrate. The two capacitors can be wired in series such that the metal bottom plates form independent, electrically driven connections. The thin top layer can form a top plate. Changes in humidity affect the humidity sensitive dielectric thereby causing changes in the capacitive value. A P-well layer and a P-plus layer can be added at the perimeter of the substrate to create a path for a parasitic capacitance caused by water condensation to connect to one or more connection nodes, thereby preventing erroneous measurements of humidity in the presence of water condensation.

Abstract: An apparatus for marking a bale of bulk material, such as a bale of fodder having a frame defining a gap through which passes the baled material. A marking system, typically comprising of at least one spray can operates to mark the bale. One specific use of the invention is where the moisture of a bale of fodder is measured and if it exceeds a predetermined level the bale is sprayed with a can of spray paint to indicate to a person that the moisture content of the bale is higher then a set threshold.

Abstract: An apparatus for cooking foods comprises a cooking chamber provided with humidity-detecting device arranged in such a way as to detect the humidity in said cooking chamber, wherein said humidity-detecting device comprises a capacitive sensor; a system for controlling the humidity in a chamber for cooking foods comprises a humidity detecting device provided with a capacitive sensor.

Abstract: A contaminant detector disposed within a base fluid for detecting the presence of a contaminating fluid includes a conductive core, a conductive sensor probe extending from the core in non-conductive relation, and a circuit board within the core. The circuit board is electrically connected to the sensor probe and electrically insulated from the core. Electrical power applied to the core creates a closed field loop for measuring the localized capacitance of the base fluid. When sufficient contaminating fluid exists in the base fluid to change the localized capacitance, an alarm is sounded to indicate the presence of the contaminating fluid.

Abstract: An absolute moisture sensor is coupled to a controller circuit with the combination being integrated into a single device as a moisture-activated switch. The resultant switch is coupled in series with a power control line of a moisture-controlling device and can be placed within the medium for which moisture is to be controlled. In one typical use, the switch is buried in soil for control of valves that supply irrigation water. Since the moisture sensor is selected to provide an absolute reading of moisture, the switch programs itself when power from an external source is first applied. A communication protocol provides for readout of sensor values and allows for a remote reset of the controller.

Abstract: A sensor for measuring the moisture and salinity of a material is disclosed herein. The sensor preferably includes a soil moisture circuit, a soil salinity circuit and a probe structure. The soil moisture circuit includes a high frequency oscillator, a voltage meter and a reference capacitor. The soil salinity circuit includes a low frequency oscillator, a voltage meter and a reference resistor. A third voltage meter allows for voltage outputs to be measured to calculate soil moisture and soil salinity values.

Abstract: The invention presents an apparatus and techniques for determining whether a medical electrode, such as a defibrillation electrode coupled to an automated external defibrillator, is in a condition for replacement. The determination can be made as a function of one or more data. In one exemplary embodiment, the determination is a function of one or more measurements of an impedance of a hydrogel bridge in a test module. In another exemplary embodiment, the determination is a function of one or more environmental condition data from one or more environmental sensors.

Abstract: A sensor for measuring the moisture and salinity of a material is disclosed herein. The sensor preferably includes a soil moisture circuit, a soil salinity circuit and a probe structure. The soil moisture circuit includes a high frequency oscillator, a voltage meter and a reference capacitor. The soil salinity circuit includes a low frequency oscillator, a voltage meter and a reference resistor. A third voltage meter allows for voltage outputs to be measured to calculate soil moisture and soil salinity values.

Abstract: Soil moisture sensor systems and methods are disclosed. An exemplary soil moisture sensor system includes a sensor configured to receive soil between parallel plates. A capacitive measurement circuit is operatively associated with the parallel sensor. A processor receives input from the capacitive measurement circuit. The processor determines moisture content of the soil between the parallel plates of the sensor based on the flowing relationship: C = LH d ? ? 0 ? ? r where L is the length of the sensor, H is the height of the sensor, and d is the separation between the parallel plates of the sensor.

Abstract: A capacitive humidity sensor includes a detecting portion and a reference portion. The detecting portion includes a first sensor element, and a capacitance of the first sensor element varies in accordance with humidity. The reference portion includes a second sensor element and a capacitor. The second sensor element is connected to the first sensor element in series, and a capacitance of the second sensor element varies in accordance with the humidity. The capacitor has a constant capacitance relative to a humidity variation. The first sensor element has a gradient of a capacitance variation to the humidity variation, which is different from a gradient of the second sensor element.

Abstract: A fluid sensor detects property of fluid by dipping the sensor in the fluid. The sensor includes: a semiconductor substrate; and a comb-teeth electrode made of a first diffusion layer and disposed on a first surface of the substrate. Although the comb-teeth electrode is capable of directly contacting the fluid without a protection film, corrosion resistance of the sensor against the fluid is improved. Further, since the sensor has no protection film, the sensor can detect the property accurately.

Abstract: A system and/or method for sensing the presence of moisture (e.g., rain) and/or other material(s) on a window such as a vehicle window (e.g., vehicle windshield, sunroof or backlite). In certain example embodiments, a plurality of sensing capacitors are supported by a window such as a vehicle windshield, the capacitors each having a different field and/or pattern. A sensing circuit outputs an analog signal that is based on and/or related to the capacitances of one or more of the sensing capacitors. In certain example embodiments, a flexible printed circuit board (PCB) mountable in or on a vehicle window is provided. First and second sensing circuits are formed on opposing sides of the flexible PCB, with each said sensing circuit comprising a plurality of different fractal structures.

Abstract: A sensor for measuring the moisture and salinity of a material is disclosed herein. The sensor preferably includes a soil moisture circuit, a soil salinity circuit and a probe structure. The soil moisture circuit includes a high frequency oscillator, a voltage meter and a reference capacitor. The soil salinity circuit includes a low frequency oscillator, a voltage meter and a reference resistor. A third voltage meter allows for voltage outputs to be measured to calculate soil moisture and soil salinity values.

Abstract: A humidity sensor apparatus and method of forming the same. A substrate can be provided upon which a plurality of humidity sensing components are disposed to form a humidity sensor thereof. Each humidity sensing component generally includes an associated particular parasitic capacitance. This parasitic capacitance is utilized to reduce and/or control a sensitivity and a total capacitance value associated with the humidity sensor without increasing a size of the humidity sensor and/or humidity sensor components (e.g., capacitors).

Abstract: A device for determining the residual liquid content of solids cakes in a centrifuge basket. The device includes two electrodes protruding through a wall of the basket and into the solids cake; a conductivity or capacitance measuring device (13) measuring the conductivity of the solids cake between the electrodes; and evaluation and control units contactlessly receiving data from the measuring device to affect the operation of the centrifuge.

Abstract: An apparatus and method for determining and monitoring the moisture content of an elastomer material used as a closure or stopper for containers holding lyophilized pharmaceutical products, comprising a parallel capacitance circuit formed by supplying a source of AC voltage to a reference elastomer closure and a sample elastomer closure. The capacitance of the sample elastomer closure is measured and compared with the capacitance of the reference elastomer closure. The difference in capacitances of the sample elastomer closure and the reference elastomer closure allow the absorbed moisture content of the sample closure to be determined or monitored. The method does not require destruction of the sample elastomer closure, and can be used to rapidly determine moisture content under normal storage conditions or at elevated or lower temperatures.

Abstract: A moisture sensor device includes a sensor portion having a capacitance that is varied in accordance with surrounding humidity, a signal processor for processing a detection signal of the sensor portion and outputting the signal corresponding to the humidity, a heating portion for heating the sensor portion, and a controller for controlling heating of the heating portion so that the capacitance of the sensor portion is substantially equal to a value under predetermined humidity at least during a self-diagnosis period.

Abstract: A capacitive soil moisture sensor that is easy to install, does not require complex calibration, can sense moisture at a particular depth, can accommodate soils of different composition, does not alter soil densities, provides fast response to changes in moisture and provides stable long term use. The sensor comprising of a body (10) onto which is attached a plurality of first electrode (20) and a plurality of second electrode (30). A plurality of protective layer (50) of low dielectric constant material is applied over the electrodes and against the body (10) to provide a physical barrier to prevent a conduction path from the first electrode (20) to the second electrode (30) and to provide protection against physical damage. The first and second electrodes (20), (30), once inserted into the soil, forms a capacitor with the soil as the dielectric. A change in soil moisture causes the capacitance of the sensor to change.

Abstract: A grain moisture meter has a test cell for containing a sample of the particulate material to be tested. A single oscillator includes a variable frequency tuned circuit including the test cell as a capacitor, a calibrated variable standard capacitor, a calibrating capacitor and a variable trimming capacitor. A frequency monitor generates DC voltage outputs of opposite polarity according to whether the output frequency of the oscillator is greater than or less than the selected frequency and displays the frequency difference as zero when the circuit is tuned. The calibrating capacitor is operator adjustable and a fixed reference capacitor and a reference number are provided to allow the operator to set the calibrating capacitor.

Abstract: A process is disclosed for evaluating a measuring device comprising a capacitor (CM), with stages for charging the capacitor (CM) over an initial charging period (tk1, tk2) and for determining the capacitance charge as an initial measured value (tml). To determine a measuring condition that changes a normal state of the capacitance, e.g., moist as opposed to dry surroundings for the measuring cell, the process exhibits the following additional steps: charging the capacitance (CM) over a second charging period (tk2), which differs from the first charging period (tk1); determining the charge of the capacitance (CM) as a second measured value (tm2); and comparing the first and second measured values (tk1, tk2) to establish the comparative result.

Abstract: A moisture sensing apparatus includes an oscillator for supplying an AC signal to a driven ring of a sensor having a pad inside the ring, and a ground plate around the ring. An amplifier forms part of a temperature-compensated, precision rectifier, and is connected to the pad. A first diode connected to the output of the amplifier in a feedback loop of the amplifier, where the amplifier nullifies temperature variation effects upon the diode, and supplies a rectified signal which is a function of moisture content of material in contact with the sensor. A second diodes is connected between the amplifier output and other input of the amplifier. The sensor has a rounded configuration to avoid electrostatic field fringing effects, and a passive impedance with both resistive and capacitive members is connected in parallel with the sensor to provide a functional baseline for the rectified signal.