The present invention relates to an oscillating sensor for a measurement device comprising: an oscillator comprising a resonance circuit for providing an oscillation signal; a gain stage configured to feed back to the resonance circuit to inject energy for excitation of the resonance circuit to maintain oscillation; at least one calibration element to adjust the open loop gain of the oscillator; a calibration unit to provide a modulated calibration control signal to selectively adjust an electrical measure of the at least one calibration element based on at least one predetermined duty cycle,
wherein the modulated calibration control signal has an irregularly time-varying cycle frequency.

The invention relates to an oscillating sensor for a measurement device comprising: an oscillator comprising: a resonance circuit for providing an oscillation signal; a gain stage configured to provide a feed-back to the resonance circuit to inject energy for excitation of the oscillator to maintain oscillation; at least one calibration element to adjust the open loop gain of the oscillator; a calibration unit to provide a modulated calibration control signal to selectively adjust an electrical measure of the at least one calibration element based on at least one predetermined duty cycle, wherein the calibration unit is further configured to provide the modulated calibration control signal with at least one cycle frequency which depends on the oscillation frequency.

Non-invasive systems for and methods of determining fluid characteristics within a fluid vessel are disclosed. The methods can include providing a sensor system comprising a single coil magnetic induction conductivity sensor, a processor, and a computing system configured to run an analytical coil-loss model. The method can include calibrating the sensor system to the vessel to provide a column calibration factor. The column calibration factor is dependent upon a cross-sectional area of the vessel and a wall thickness of the vessel. The single coil magnetic induction conductivity sensor can be placed near an external surface of the vessel at a portion of the vessel that is non-conductive. The method can include generating a coil loss measurement utilizing the single coil magnetic induction conductivity sensor and converting the coil loss measurement to a conductivity value of the fluid within the vessel.

An inductive-capacitive (LC) wireless sensor for the detection of toxic heavy metal ions includes inductors and interdigitated electrodes (IDE) in planar form. The sensor is fabricated by screen printing silver (Ag) ink onto a flexible polyethylene-terephthalate (PET) substrate to form a metallization layer. Palladium nanoparticles (Pd NP) is drop casted onto the IDEs to form a sensing layer. The resonant frequency of the LC sensor is remotely monitored by measuring the reflection coefficient (S.sub.11) of a detection coil (planar inductor). The resonant frequency of the LC sensor changes with varying concentrations of heavy metals such as mercury (Hg.sup.2+) and lead (Pb.sup.2+) ions. Changes in the resonant frequency are used to detect the presence and/or concentration of heavy metal ions.

A metal detection apparatus (9) is tested with a test device (7) having at least one test article (79), movable through a detection zone (60). The test article is moved through the detection zone along a first transfer axis (ca) and a first input signal is measured. A first threshold (th1) is determined, where an amplitude of the first input signal exceeds the first threshold (th1). Then, an identical test article is moved through the detection zone along a further transfer axis (ta; . . . ) and a further input signal is measured and a further threshold (th2; . . . ) is determined, where an amplitude of the further input signal exceeds the further threshold (th2; . . . ). The first or further threshold (th1; th2; . . . ) is selected in the signal processing path (4) whenever the test article is moved along the related transfer axis (ca; ta; . . . ).

A system may include a resistive-inductive-capacitive sensor, a driver configured to drive the resistive-inductive-capacitive sensor at a driving frequency, and a measurement circuit communicatively coupled to the resistive-inductive-capacitive sensor and configured to measure phase information associated with the resistive-inductive-capacitive sensor and based on the phase information, determine a displacement of a mechanical member relative to the resistive-inductive-capacitive sensor, wherein the displacement of the mechanical member causes a change in an impedance of the resistive-inductive-capacitive sensor.

Non-contact type measuring apparatus able to detect a difference in signal intensity by transmitting a radio frequency (RF) signal having a predetermined frequency through one of two coil antennas and receiving an induced RF current signal transmitted via a medium through the other coil antennas and detect conductivity and a variation in characteristic of a non-conductor by comparing the signal intensity with a signal intensity comparison table for each frequency, which is stored in a controller by measuring a signal intensity for each frequency in advance, on the basis of the signal intensity for each frequency. The non-contact type measuring apparatus can accurately measure not only various elements using a characteristic in which conductivity is varied according to total dissolved solid, temperature, and an amount of a conductive medium and permittivity change characteristic of a non-conductor, but also conductivity and variation in characteristic of the non-conductor.

A biomagnetic field measuring apparatus enabling reliable biomagnetic field measurements in clinical practice, having a plurality of magnetic field sensors being arranged in an array in a sensor plane, including a plurality of first magnetic field sensors being designed and configured to measure a first component of the magnetic field, a plurality of second magnetic field sensors being designed and configured to measure a second component of the magnetic field, and a plurality of third magnetic field sensors being designed and configured to measure a third component of the magnetic field, the first, second and third components of the magnetic field being orthogonal to each other. Viewed perpendicular to the sensor plane, the first magnetic field sensors and the second magnetic field sensors are arranged essentially centrally and the third magnetic field sensors are arranged essentially around the first and second magnetic field sensors.

In one embodiment, a sensor arrangement for the contactless sensing of angles of rotation on a rotating part includes a disk-shaped target, a coil arrangement, and an evaluation and control unit. The disc-shaped target is coupled to the rotating part and includes at least two metal surfaces that influence the inductances in the flat detection coils due to eddy current effects as a function of the degree of overlap. The disc-shaped target can generate at least one piece of information for ascertaining the instantaneous angle of rotation of the rotating part, in connection with the coil arrangement. The coil arrangement has three flat detection coils uniformly distributed on the circumference of a circle. The evaluation and control unit can generate essentially sinusoidal evaluation signals which represent the changes in inductance of the detection coils and can evaluate them for calculating the angle of rotation.

Methods and systems for detection of threats in secure areas are disclosed. Microwaves are transmitted into high traffic areas and are reflected off or transmitted through targets within that area. The resulting signals are detected at receiving antennas which are designed to have a high cross-polarization discrimination (XPD) such that co- and cross-polarizations of the resulting signals are separable for further processing. The receiving antennas of the present invention comprise elliptical antennas with a double-ridged waveguide on the interior and a conically-shaped exterior. This particular design for the receiving antennas allows to technologically obtain an XPD of about 30 dB or more for solid angles measured from a receiving antenna's boresight (the main lobe axis), and formed by rotating the corresponding 30-degree planar angle around the main lobe axis, the solid angles measuring approximately 0.84 sr, in a frequency range between 9.5 and 20 GHz.