The invention relates to a method for determining a coupling between magnetometers of an array of N magnetometers, for example with optical pumping, where each magnetometer comprises a field cancellation system capable of being activated to operate the magnetometer in zero field. This method comprises a first phase (P1) during which the N magnetometers are separated into N−1 magnetometers whose field cancellation system is deactivated and a measuring magnetometer whose field cancellation system is activated. This first phase comprises: the generation (GENj), by the magnetometers, of a plurality of reference magnetic fields of known amplitudes and distinct directions, the measurement (MESi), by the measuring magnetometer, of the ambient magnetic field on a plurality of measurement axes determination (CALCij) of coupling coefficients between the measuring magnetometer and each of the N magnetometers from said measurement and said known amplitudes.

Current sensing techniques. In an example, a current sensing method includes: generating a first magnetic field measurement; generating a second magnetic field measurement; generating a frequency estimate of a current; calculating a root-mean-square (RMS) value of an estimated amplitude of the current; and generating a temperature estimate of an integrated circuit (IC) configured to perform the method. The method also includes generating a first weighting factor and a second weighting factor based on the frequency estimate, the RMS value, and the temperature estimate, the first weighting factor to control amplification of the first magnetic field measurement and the second weighting factor to control amplification of the second magnetic field measurement.

A digital compass with two or more multi-axis magnetometers and a processing element to determine a heading and detect any offset error in the heading is described. One electronic device includes first and second magnetometers. The second magnetometer can be disposed at least a specified distance or co-located and offset at least a specified angle from the first magnetometer. A processing device determines a magnetic field at the electronic device using a first output from the first magnetometer, detects an offset error in the magnetic field using a second output from the second magnetometer, and reports the offset error in the magnetic field.

A magnetic sensor circuit includes a plurality of magnetic sensors having bias input and bias output terminals and first and second measurement terminals. The circuit includes a diagnostic sensor having bias input and bias output terminals and first and second measurement terminals. The circuit includes a first multiplexer configured to selectively couple a current source to the bias input terminals of the magnetic sensors or to the bias input terminal of the diagnostic sensor and includes a second multiplexer configured to selectively couple the bias output terminals of the magnetic sensors or the bias output terminal of the diagnostic sensor to a first terminal of a switch. The circuit includes a third multiplexer configured to selectively couple the measurement terminals of the magnetic sensors or the measurement terminals of the diagnostic sensor to differential input terminals of an amplifier.

A system and method for calibrating rigid and non-rigid arrays of 3-axis magnetometers as disclosed. Such arrays might be used to analyze structures containing ferromagnetic material. The calibration determines scale factor and bias parameters of each magnetometer in the array, and the relative orientation and position of each magnetometer in the array. Once the parameters are determined, the actual magnetic field value at the magnetometer location can be simply related to magnetometer measurements. The method and system can be used to calibrate an array of 3-axis magnetometers in aggregate as opposed to individual magnetometers. This is critical in large arrays to increasing reproducibility of the calibration procedure and decreasing time required to complete calibration procedure.

Methods and apparatus for a magnetic sensor having a die and sensor circuitry formed in a device layer of the die with a coil integrated with the die to generate a magnetic field. A magnetoresistive magnetic field sensing element on the die detects changes in the magnetic field generated by the coil as a result of the presence of a ferromagnetic target. The sensor circuitry may process the changes in the magnetic field generated by the coil.

A laboratory system for a laboratory automation system is presented. The laboratory system comprises a sample container carrier. The sample container carrier is configured to carry a laboratory sample container and comprises a removal detector. The removal detector is configured to interact with the laboratory sample container to detect a removal of the carried laboratory sample container from the sample container carrier. Furthermore, the laboratory system is configured to determine based on the detected removal that a before valid logic assignment of the sample container carrier to the carried laboratory sample container is invalid.

A magnetic field sensor comprises at least one magnetic field sensing element configured to generate a measured magnetic field signal responsive to an external magnetic field; a diagnostic circuit configured to generate a diagnostic signal, wherein the diagnostic signal is not dependent on a measured magnetic field; a signal path comprising an amplifier and an analog-to-digital converter for processing the measured magnetic field signal to generate a sensor output signal indicative of the external magnetic field during a measured time period and for processing the diagnostic signal during a diagnostic time period; and a switch coupled to receive the measured magnetic field signal and the diagnostic signal and direct the measured magnetic field signal to the signal path during the measured time period and direct the diagnostic signal to the signal path during the diagnostic time period.

One example discloses a sensor calibration circuit, including: a controller configured to transmit a first modulation signal to the sensor and receive a first output signal from the sensor in response; wherein the controller configured to transmit a second modulation signal to the sensor and receive a second output signal from the sensor in response; and wherein the controller is configured to calibrate the sensor based on the first and second modulation signals and the first and second output signals.

A method of determining a gradient of a magnetic field, includes the steps of: biasing a first/second magnetic sensor with a first/second biasing signal; measuring and amplifying a first/second magnetic sensor signal; measuring a temperature and/or a stress difference; adjusting at least one of: the second biasing signal, the second amplifier gain, the amplified and digitized second sensor value using a predefined function f(T) or f(T, ΔΣ) or f(ΔΣ) of the measured temperature and/or the measured differential stress before determining a difference between the first/second signal/value derived from the first/second sensor signal. A magnetic sensor device is configured for performing this method, as well as a current sensor device, and a position sensor device.