System and method of concentrating (or aligning) analytes at a droplet-bulk solution interface as a means of enhancing a detection sensitivity of the analytes at electrodes in a fluidic channel. A number of differing types of intermolecular forces and chemicals or materials can be employed to accomplish the concentrating (and/or aligning). For example, a measurement analogous to a conventional electrical impedance spectroscopy (EIS) measurement can be made by bringing an analyte (e.g., a molecule to be detected) to the edge of a droplet, and in so doing, positioning the analyte close to an electrode surface to aid in detection.

Automated measurement of fluid solution capacitance in industrial processes to determine solution concentration. Industrial process control transmitters determine solution concentration directly from solution capacitance and confirm concentration determinations based on solution conductivity. The industrial process control transmitters include terminals embodied in wire coils and/or metallic plates, at least one processor, and at least one computer readable memory device.

Methods, devices and systems for three-dimensional location of the disposition of a sensor coil in a subject including are disclosed. The systems include an array of three or more triplet or quadruplet drive coil sets, at least one moveable sensor coil configured to be disposed in a subject and to provide one or more sensor coil response signals responsive to the respective electromagnetic wave fields, a receiving component configured to control drive signals to the array of drive coil sets and to measure sensor coil response signals from the moveable sensor coil, and a processor is configured to determine a sensor coil disposition in the subject relative to said triplet or quadruplet drive coil sets. The receiving component provides a modified drive signal to maximize or optimize the generated respective electromagnetic wave fields, or the one or more sensor coil response signals.

A conveyor belt and a sensing system for sensing various conditions on a conveyor belt. The belt includes an array of sensing elements embedded in the belt to measure belt conditions. The sensing elements form parts of passive resonant circuits that each include a capacitor and an inductive coil. The capacitor or the inductive coil can be a sensing element. Measuring circuits external to the belt are inductively or capacitively coupled to the resonant circuits in the belt as they pass closely by. The sensing elements change the resonant frequency of their resonant circuits as a function of the sensed conditions. Frequency detectors in the measuring circuits measure that frequency change and convert it into a functionally related value used to determine a belt condition. Exemplary conditions include temperature, pressure, humidity, spillage, and product weight.

Apparatus and methods for reactance measurements are disclosed. The apparatus and methods are particularly suitable for eddy current proximity sensors in turbo-machine assemblies. In one arrangement, there is provided an apparatus comprising a circuit for receiving a sensing component of a sensor. The circuit has a unit having fixed reactance. An electrical source is provided for driving an alternating current through the circuit. An analysis unit measures the phase of a signal in the circuit that is dependent on the reactance of the sensing component. A measure of the reactance of the sensing component is output based on the measured phase.

A metal detector has a transformer unit (1), a transmitter unit (2), a receiver coil set (3), a signal processing unit (4) and a control unit (5). The transformer unit provides an input signal (s.sub.IN) with selectable operating frequency (f.sub.TX) to an amplifier stage (12), that is connected to a transmitter coil (21) that is coupled to first and second receiver coils (31, 32). The coil outputs are connected to the signal processing unit, which has a receiver unit (41) and a signal processor (42). A coupling transformer (13) has first and second windings (13A, 13B), connected to the output of the amplifier stage, and a third winding (13C), connected to the transmitter coil. The first and second windings are each connected at a first end to a supply voltage (+Ub). Each of the first and second windings has at least one tapping (141, 142, 143, 144; 141, 142, 143, 144) at a same turn number counted from the first end. The amplifier stage has first and second amplification wings (12A, 12B). Each of these is associated with a power transistor connected to one of the at least one tappings of the corresponding winding, so the first and second amplification wings amplify the corresponding first and second half waves of the input signal.

A quality value for a carbon ceramic brake disc (2) in a vehicle is measured by means of a measuring device (3) installed in the vehicle. The measuring device (3) with a coil (10) is located at a distance (d) from the brake disc (2) in order avoid direct physical contact with the brake disc. The impedance of the coil (10) is measured for at least two frequencies. The resulting measurement values that correlate to impedance values are introduced into a mathematical model in order to eliminate the dependence of the unknown distance (d) and to obtain a quality value dependent on the conductivity of the brake disc (2).

A system for detecting disposal of metallic objects into an opening of a medical waste container, including: an indicator for indicating passage of metallic objects through the opening, a pair of receive coils and a transmit coil spaced therebetween shaped for receiving waste therethrough adjacent to the opening, and a controller in electrical communication with the coils. The controller generates and communicates a transmit signal to the transmit coil, which generates a magnetic field that induces voltage in each of the receive coils, which each generate a receive signal. The controller generates a waveform based on the receive signals with a baseline corresponding to absence of metallic objects, and analyzes the waveform with respect to opposite first and second thresholds. The controller activates the indicator in response to metallic objects passing through the coils when the waveform first exceeds the first threshold and then subsequently exceeds the second threshold.

A metal detection apparatus includes a detector housing with input and output apertures delimiting a transfer channel for moving products through a coil system with a transmitter coil for inducing signals in receiver coils that do not compensate one another when a metal contaminant is in the detection zone. A test device includes at least one sample, a signal processing unit for processing the receiver coil signals and detecting signals relating to contaminants and the test sample, and a control unit for controlling measurement of products during normal operation and the sample during test intervals. The test device includes reel units at the input and output apertures, respectively, with drive units rotatably holding reels holding ends of an elongated windable sample carrier extending through the detection zone and holding the sample(s). Either or both of the reel drive units transfer the sample(s) through the detection zone during test intervals.

A tomography system for determining properties of flowing multiphase fluid, comprising a duct having a duct wall and interior space within the duct wall for carrying a flow of the multiphase fluid and a plurality of sensors, which are electrodes or coils, at positions distributed around the duct wall on a planar cross section through the duct, wherein the sensors (electrodes or coils) are used for making a plurality of measurements of electrical or magnetic properties through the duct wall and the multiphase fluid; and a processor is used to receive measurement data from the sensors and to compute from the measured properties to derive quantitative values of at least one property selected from permittivity, conductivity, magnetic permeability and complex-conductivity of the multiphase fluid independent of effects external to the fluid flow, such as effects of the duct walls and the geometry of the positioning of the sensors (electrodes or coils).