A capacitive detection device that may include at least one electrode of a capacitive sensor, an alternating voltage source, a device for measuring a complex value of impedance or admittance between the detection electrode and an electrical circuit reference point and a calibration resistor, and a switching device arranged so as to connect the voltage source to the electrode, in the measurement mode, and to connect the voltage source to the calibration resistor and disconnect the voltage source from the electrode, in the calibration mode. The measuring device is arranged so as to measure a first complex value of the calibration resistor, during operation in the calibration mode; to measure a second complex value between the electrode and the electrical circuit reference point during operation in measurement mode, and to correct the second measured complex value according to the first measured complex value.

A metal detector detects when a target that is a desirable metal object is located within a medium. A signal is transmitted into the medium. A response signal is received from the medium. The response signal includes a secondary medium response signal from the medium and includes a secondary target response signal from the target when the target is located within the medium. The response signal is amplified to produce an amplified signal. Compensation circuitry perform transmit coil transfer function compensation on the amplified signal to produce a compensated signal. A notch module removes a resistive component of the secondary medium response signal from the compensated signal.

A metal detector detects when a target that is a desirable metal object is located within a medium. A signal is transmitted into the medium. A response signal is received from the medium. The response signal includes a secondary medium response signal from the medium and includes a secondary target response signal from the target when the target is located within the medium. The response signal is amplified to produce an amplified signal. Compensation circuitry perform transmit coil transfer function compensation on the amplified signal to produce a compensated signal. A notch module removes a resistive component of the secondary medium response signal from the compensated signal.

A method for calibrating an optical sensor in a Bluetooth headset and a Bluetooth headset are provided. The Bluetooth headset includes an optical sensor and a command execution device, the Bluetooth headset is connected to a charging box which is adapted to the Bluetooth headset, and a command initiation device and a command transmission medium are arranged in the charging box. With the method, if the command initiation device is triggered, the command initiation device sends a calibration command to the command execution device via the command transmission medium; and the command execution device calibrates an optical sensor in response to the calibration command to obtain a calibration result, and stores the calibration result.

A method for calibrating an optical sensor in a Bluetooth headset and a Bluetooth headset are provided. The Bluetooth headset includes an optical sensor and a command execution device, the Bluetooth headset is connected to a charging box which is adapted to the Bluetooth headset, and a command initiation device and a command transmission medium are arranged in the charging box. With the method, if the command initiation device is triggered, the command initiation device sends a calibration command to the command execution device via the command transmission medium; and the command execution device calibrates an optical sensor in response to the calibration command to obtain a calibration result, and stores the calibration result.

A sensor package may include a sensor housing unit and a first sensor that may acquire a first set of measurements within a first measurement range. The sensor package may also include a second sensor configured to acquire a second set of measurements within a second measurement range. The first measurement range and the second measurement range may include an overlapping range used to calibrate the first set of measurements, the second set of measurements, or both.

Certain aspects of the present disclosure relate to calibrating a formation signal for a mixed set measurement device. A first air-hang response of a first measurement device for a tubular string associated with a drilling operation can be measured. A second air-hang response of a second measurement device for the tubular string associated with the drilling operation can be measured. The first air-hang response and the second air-hang response can be used to determine a mixed air-hang response of the mixed set measurement device. The mixed air-hang response can be used to calibrate a formation signal for the mixed set measurement device.

In some examples, the disclosure provides a method for determining a drift in clock data that is provided by a clock of a seismic sensor. The sensor is exposed to an ambient temperature that varies over time. The method includes obtaining temperature data associated with the ambient temperature as a function of time. The method also includes obtaining the clock data. The method also includes obtaining timestamp data provided by a global navigation satellite system. The method also includes determining drift data which minimizes a difference of a temporal drift in the clock data, based on the timestamp data and the temperature data. The method also includes outputting corrective data based on the determined drift data.

A magnetometer-based metal detection device and methods of use are described. The device includes a proximal portion, a central body and a distal portion, and at least one magnetometer positioned within or on the distal portion. The at least one magnetometer includes at least one sensor capable of sensing a magnetic field in three orthogonal axes. Also described is a method of calibrating the device to achieve rotational invariance, and a method of determining a directionality or directional line along which a target metal object lies.

A magnetometer-based metal detection device and methods of use are described. The device includes a proximal portion, a central body and a distal portion, and at least one magnetometer positioned within or on the distal portion. The at least one magnetometer includes at least one sensor capable of sensing a magnetic field in three orthogonal axes. Also described is a method of calibrating the device to achieve rotational invariance, and a method of determining a directionality or directional line along which a target metal object lies.