Design and Development of a New Magnetometer Calibration Device

This paper describes the development of a new magnetometer calibration device using an active magnetic field compensation technique based on the base quantity of time rather than secondary standard field measurements. The proposed arrangement can be used as a laboratory calibration device that monitors and compensates the ambient dc magnetic field in a magnetically quiet environment. Furthermore, it can be developed to serve as a laboratory primary standard since it is based on the measurement of a base quantity, such as time. The proposed technique is based on the fluxgate magnetization principle and the measurement of the time difference between the two successive output pulses. The laboratory arrangement consists of a long solenoid for 1-D applications, which may be extended to 2-D and 3-D using Helmholtz coils, and a microcontroller for fast signal processing operations, which evaluate and compensate the detected ambient magnetic field using a closed-loop control algorithm. The proposed arrangement is used to obtain the calibration curves of a commercial Hall and a custom-made fluxgate sensor.