An electronic position encoder includes a scale and detector. The detector includes a field generating coil (FGC) having elongated portion configurations (EPCs) bounding a generated field area (GFA) aligned with sensing elements in a sensing area, to provide position signals responsive to the scale interacting with the generated field. Sensing elements and EPCs are fabricated in “front” layers of the detector portion. The EPCs include end gradient arrangements (EGAs) configured to reduce field strength in the generated field area as a function of position along the x-axis direction for positions approaching the end of the GFA. A shielded transverse conductor portion (TCP) fabricated in a “rear” layer connects the EPCs and/or EGAs of the FGC via feedthroughs. A conductive shield region (CSR) configuration in a CSR layer between the front and rear layers intercepts at least a majority of a projection of the TCP toward the front layers.

An inductive position sensor may be configured to detect relative position between a first member and a second member. The inductive position sensor may include a transmit aerial configured to be disposed on the first member. The inductive position sensor may include a receive aerial configured to be disposed on the first member. The inductive position sensor may include processing circuitry configured to provide one or more signals indicative of the relative position between the first member and the second member based on a receive signal induced in the receive aerial resulting from a signal provided to the transmit aerial. One or more of the transmit aerial and the receive aerial may include one or more windings. A shape of the one or more windings can be a combination of a sinusoidal waveform and one or more scaled harmonics of the sinusoidal waveform.

An inductive sensor device includes a reference sensor head that is used to adjust the characteristics of an operational sensor head that is used to detect movement of a conductive target. The reference sensor head has near it a fixed reference target that is similar to the target for which the operational sensor head detects movement, with the difference that the reference target is fixed with respect to a reference sensor coil of the reference sensor head. The reference sensor head includes a variable reference capacitor or variable reference inductor that is adjusted to maintain constant (or nearly constant) output, such as a constant (or nearly constant) resonant frequency, during operation of the sensor device. Adjustments of the variable reference element (variable capacitor or variable inductor) may be undertaken to compensate for changes in characteristics of the reference sensor due to changes in temperature, for example.

A method for defining a measurement range, called the useful span, of the inductive position sensor with emission of a cosine and sine signal by at least one first receiver winding and at least one second receiver winding, respectively. The cosine signal emitted by the one or more second receiver windings is taken as reference signal between the two sine and cosine signals for an adjustment of at least one parameter of the sine signal depending on a corresponding parameter of the cosine signal, at least one of the dimension and positioning parameters of the one or more first receiver windings being configured to generate a sine signal having the at least one parameter of the sine signal adjusted with respect to the cosine signal.

An angular rotation sensor system constituted of: a first target with a member radially extending from, and rotating about a longitudinal axis of the first target; a second target with a member radially extending from, and rotating about a longitudinal axis of the second target; a first receive coil comprising a plurality of loops laid out such that adjacent loops exhibit opposing magnetic polarities responsive to a radio frequency current injected into the transmit coil; a second receive coil comprising a plurality of loops laid out such that adjacent loops exhibit opposing magnetic polarities responsive to a radio frequency current injected into the transmit coil; and an output coupled to each of the first and second receive coils, wherein each of the members is shaped and sized to generally match a shape and size of a pair of loops.

An angular rotation sensor system constituted of: a first target with a member radially extending from, and rotating about a longitudinal axis of the first target; a second target with a member radially extending from, and rotating about a longitudinal axis of the second target; a first receive coil comprising a plurality of loops laid out such that adjacent loops exhibit opposing magnetic polarities responsive to a radio frequency current injected into the transmit coil; a second receive coil comprising a plurality of loops laid out such that adjacent loops exhibit opposing magnetic polarities responsive to a radio frequency current injected into the transmit coil; and an output coupled to each of the first and second receive coils, wherein each of the members is shaped and sized to generally match a shape and size of a pair of loops.

This inductive position sensor is designed to measure the angular position of a shaft or the like and includes a support on which are realized, on the one hand, a primary winding, and on the other hand, at least two secondary windings in phase opposition with respect to each other. Each secondary winding is defined by a set of at least two loops in phase with each other. The secondary windings are connected in series and each arranged symmetrically with respect to a middle line so as to form each time a pattern on either side of this middle line, the two patterns having a separation between them in the area of said middle line. An assembly including such a sensor and a target with two oppositely directed helices.

An inductive position sensor designed to measure the angular position of a shaft or the like and includes a support on which are realized, on the one hand, a primary winding, and on the other hand, at least two secondary windings in phase opposition with respect to each other. Each secondary winding is defined by a set of at least two loops in phase with each other. The secondary windings are connected in series and each arranged symmetrically with respect to a middle line so as to form each time a pattern on either side of this middle line, the two patterns having a separation between them in the area of said middle line. An assembly including such a sensor and a target with two oppositely directed helices.

A magnetic sensing tool (MST) uses differentials in induced voltage to detect the approximate location of a ferric target tool within surface pressure control equipment associated with a wellhead. The MST comprises a transmitter coil and two receiver coils configured such that a voltage generated in the transmitter coil induces a baseline voltage, and a baseline voltage differential, in the receiver coils when no target tool is present. A target tool passing axially through the MST will disrupt the magnetic fields inducing the voltages, such that variations in the voltage differential can be used to detect the approximate location of the target tool. The MST can be deployed alone or in series depending on the requirements of detection of the target tool.

Noncontact measurements of positions of electrically-conductive objects is achieved by placing two conductive coils formed by traces on printed circuit boards (PCBs) in the proximity of the object surface, energizing one of the coils (excitation coil) with alternating electrical current and measuring the amplitude of the voltage induced on the terminals of the second coil (sensing coil). The alternating magnetic field generated by the current in the excitation coil induces eddy currents in the object, which affect the amplitude of the voltage induced on the terminals of the sensing coil. The sensing coil voltage depends on the mutual position between the object and the sensing coil, allowing the object position measurement. The excitation coil is integrated into a series LCR circuit driven by an output of an adjustable gain amplifier at the resonance frequency. The adjustable amplifier gain is constantly adjusted to maintain the sensor sensitivity constant.