The present disclosure relates to a sensor and a measuring system and a sensor network that incorporate one or more such sensors. An example sensor could be configured to measure a conductivity of a liquid. The sensor includes a first electrode and a second electrode, each electrode having a surface area, wherein the surface area of the electrodes determines a cell constant of the sensor (Kcell), and wherein at least one of the electrodes is provided with a switching means arranged so that the surface area of the respective electrode can be changed, thereby varying the cell constant (Kcell) of the sensor.

One embodiment of a fluid cup and holder for the fluid cup for use with an electromagnetic detection device, thereby allowing a change to be detected in a fluid placed in the cup.

The eddy current sensor includes a first detector that detects an eddy current generated in a semiconductor wafer WH and a second detector that detects the eddy current. The first detector includes a first exciting coil configured to generate the eddy current and a first detecting coil configured to detect the eddy current. The first exciting coil and the first detecting coil are air-core coils. The second detector includes second exciting coil configured to generate the eddy current and second detecting coil configured to detect the eddy current. The second exciting coil and the second detecting coil are coils with a magnetic core.

The present disclosure relates to systems and methods for measuring oil/water content in oil-water mixtures, regardless of the salinity of the mixture and regardless of air in the sensor pipe. In some embodiments, the oil content is measured using a dielectric sensor. It is determined whether the oil content is above or below a threshold. If the oil content is above the threshold, the oil content is reported using the measurement from the dielectric sensor. If the oil content is below the threshold, the oil content is reported using the measurement from the eddy current sensor. In some embodiments, which improve performance when there is air in the sensor pipe, two dielectric sensors with different geometries are used instead of the one dielectric sensor.

A device for determining the parameters of strip-type superconductors includes a generator, a generator frequency-setting element, an inductance coil connected to the generator, a receiver, a receiver frequency-setting element, and an inductance coil connected to the receiver. The generator and receiver frequency-setting elements are same type narrow-band elements. The pass bands of the generator and receiver frequency-setting elements coincide through at least half of the bandwidth of the frequency-setting element having a narrower band pass width. The generator and receiver inductance coils are arranged with a gap between the same, making it possible for a strip-type superconductor to be placed between the inductance coils. The device is provided with a temperature sensor comprising a thermistor in contact with the superconductor. The device enables highly accurate and reproducible measurement results.

In certain aspects, a dialysis device includes a flow channel that includes a disposable flow-through container. The flow channel and the container contain a fluid and are in fluid communication with each other. The dialysis device also includes a toroid configured to accept, through an aperture of the toroid, at least a portion of the container. The dialysis device also includes an electromagnetic coil wrapped around the toroid, such that the coil passes around an outer surface and an inner surface of the toroid, and covers less than the entire circumference of the toroid. The coil is configured to generate an electromagnetic signal. The coil is also configured to concentrate the electromagnetic signal on the fluid in the container such that the electromagnetic signal traverses the container in a direction that is substantially parallel to the direction of flow of the flow channel. The coil is also configured to read the electromagnetic signal after it has traversed the fluid in the container.

A system includes a signal generator configured to generate a signal, the signal being a constant frequency signal or the signal ranging in frequency during a time period. The system includes a probe electrically coupled to the signal generator, and the probe is configured to hover across or touch an encapsulated or uncapsulated strain gauge. The probe includes a coil and a stylus. The coil is configured to receive the signal from the signal generator and generate a magnetic field. The stylus is configured to transmit the magnetic field to the strain gauge. The system includes a data acquisition component coupled to the strain gauge. The data acquisition component is configured to receive stimulus data from the strain gauge, resulting from the magnetic field transmitted by the probe. The data acquisition component is configured to determine whether the stimulus data from the strain gauge is above a threshold, and if so, determine that the strain gauge is operable.

An RFID-based anemia detection sensor that integrates a paper-based diagnostic device with a passive Ultra High Frequency (UHF) RFID tag. Differences in red blood cell (RBC) count in a patient's blood manifests itself as a controlled time-dependent change in the tag's signal response. In one embodiment, the sensor is capable of reliably differentiating between blood having 20, 30, 40 and 50 percent RBC concentration by volume, which is indicative of anemic vs. healthy blood. In another embodiment, the sensor is read using standard RFID equipment allowing for large-scale automated screening of blood specimens.

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.

An apparatus includes a helical flow tube in a formation testing tool. A current injector injects an electromagnetic current into the flow tube. A receiver coil is positioned to produce a receiver coil signal in response to the electromagnetic current. A processor is coupled to the receiver coil to calculate a conductivity of a fluid flowing through the flow tube based on the receiver coil signal.