Accelerometer with Hall effect sensor. The accelerometer may have a rounded magnetic assembly with rounded flux concentrator, such as a C-shape or horseshoe. Opposing ends of the concentrator may each have a magnet and form a gap having a highly-concentrated, non-linear magnetic field. Opposing ends of the concentrator may have a reduced width, such as cone-shaped. A Hall sensor may be located within or near the gap. The sensor or magnet may be moveably supported by a spring. The sensor may move perpendicularly relative to a direction of the magnetic field lines. A second magnet may be included, for example adjacent the gap, to provide a second set of magnetic field lines with shallower gradient for lower sensitivity. Movement of the sensor within the two magnetic fields may provide multiple wide-ranging sensitivities, such as X V/g as well as X/500 mV/g or X/5,000 mV/g.

Accelerometer with Hall effect sensor. The accelerometer may have a rounded magnetic assembly with rounded flux concentrator, such as a C-shape or horseshoe. Opposing ends of the concentrator may each have a magnet and form a gap having a highly-concentrated, non-linear magnetic field. Opposing ends of the concentrator may have a reduced width, such as cone-shaped. A Hall sensor may be located within or near the gap. The sensor or magnet may be moveably supported by a spring. The sensor may move perpendicularly relative to a direction of the magnetic field lines. A second magnet may be included, for example adjacent the gap, to provide a second set of magnetic field lines with shallower gradient for lower sensitivity. Movement of the sensor within the two magnetic fields may provide multiple wide-ranging sensitivities, such as X V/g as well as X/500 mV/g or X/5,000 mV/g.

An instrument package for use during the drilling a wellbore. The instrument package includes a plurality of instruments such as accelerometers, gyroscopes, and magnetometers; a computer is configured to determine the current position of the plurality of instruments from a set of measurements produced by the plurality of instruments; and wherein the plurality of instruments are mechanically isolated from a drill head assembly by one or more multi-degree of freedom vibration isolators. The computer preferably has at least two modes different analytical modes of analyzing the set of measurements produced by the plurality of instruments, including a continuous mode and a survey mode, the continuous mode being operational during times that active drilling is occurring and the survey mode being operational during times that the active drilling is not occurring.

An instrument package for use during the drilling a wellbore. The instrument package includes a plurality of instruments such as accelerometers, gyroscopes, and magnetometers; a computer is configured to determine the current position of the plurality of instruments from a set of measurements produced by the plurality of instruments; and wherein the plurality of instruments are mechanically isolated from a drill head assembly by one or more multi-degree of freedom vibration isolators. The computer preferably has at least two modes different analytical modes of analyzing the set of measurements produced by the plurality of instruments, including a continuous mode and a survey mode, the continuous mode being operational during times that active drilling is occurring and the survey mode being operational during times that the active drilling is not occurring.

An encoder for detecting angular position of a rotor in a motor includes a modular hub, configured to be connected to the rotor, and sensing electronics mounted within an end bell of the motor. The modular hub provides a universal mounting configuration for connecting different configurations of the encoder to the motor. The modular hub includes a mounting portion and sensor face on which different elements for sensing may be mounted. The elements may include polarizing tape to reflect polarized light, magnets generating a magnetic field, or ferrous teeth configured to interact with a magnetic field. The sensing electronics include sensing devices corresponding to the elements mounted on the sensor face. The sensing devices may be a paired light emitter/receiver, magnetic sensors, or a paired magnetic field generator/sensor. The sensing electronics convert the sensed signals to uniform feedback data for the motor controller regardless of the encoder configuration.

A magnetic tunnel junction (MTJ) based sensor device includes a first MTJ element, a first reservoir, a second MTJ element, a second reservoir, and processing circuitry. The first reservoir includes first particles configured to move within the first reservoir during acceleration. A first portion of the first reservoir is electrically coupled to a free layer of the first MTJ element. The second reservoir includes second particles configured to move within the second reservoir during acceleration. A first portion of the second reservoir is electrically coupled to a free layer of the second MTJ element. The processing circuitry is configured to determine an acceleration based on a first output voltage at a pinned layer at the first MTJ element and a second output voltage at a pinned layer at the second MTJ element.

A system and method wherein ball spin rate and axis orientation are determined according to an electronic circuit that includes a magnetometer spin sensor module and, in the alternative, an electronic circuit that includes a spin sensor module with a plurality of accelerometers.

A system and method wherein ball spin rate and axis orientation are determined according to an electronic circuit that includes a magnetometer spin sensor module and, in the alternative, an electronic circuit that includes a spin sensor module with a plurality of accelerometers.

Methods of determining movement and devices that can be configured to function as an accelerometer, a gyroscope or a magnetometer and is comprised of a sensing element suspended by acoustic waves, and a measurement system capable of determining the position, or rotation of the sensing element without introducing any residual force on the sensing element. The acoustic suspension of the sensing element provides a virtually friction, and torque free method of constraining the sensing element, but not hindering its ability to sense accelerations, rotations or magnetic fields.

A method for locating a casing collar in a well is disclosed. The method includes lowering an accelerometer into the well to slide along a casing wall of the well, generating a data log by measuring an accelerometer signal from the accelerometer as the accelerometer slides along the casing wall, analyzing, by a computer processor, the data log with respect to a predetermined data feature to detect an accelerometer signal event, and determining, by the computer processor and based on the accelerometer signal event, a location of the casing collar in the well.