The technology employed in the Applied Physics Systems magnetometer product line is generally referred to as a fluxgate technology. Fluxgate magnetometers employing saturable cores driven by a high frequency carrier parametrically up convert low frequency magnetic field variations to sidebands on the carrier. This approach produces a low noise, high accuracy sensor; noise level of 0.2 nanotesla RMS/√Hz and an offset drift of less than 5 nanotesla/°C are specifications for the Model 20 fluxgate magnetometer system.Read More
The fluxgate magnetometer electronics consists of a miniaturized 3-axis servo system which nulls magnetic field changes applied to the saturable cores. This design produces a very linear response over the entire dynamic range of the system.
The outstanding performance parameters of these systems are the bias and scale factor stability over temperature and time.
Recently there has been speculation on the stability of the Earth’s magnetic field. The Earth’s magnetic field magnitude is roughly 0.5 Gauss and the MicroMag can be used to measure this with great accuracy. When used as a magnetic compass, the magnetometers can be used to determine the azimuth angle of the system to which they are mounted. Specific compass applications include use in directional drilling and logging systems and use in direction finding equipment. The low noise level of the magnetometers enables magnetic anomaly detection in applications such as locating buried ordinance.
The Model 20 system outputs include 3-axis analog outputs plus an RS-232 serial digital interface. As an op- tion, internal compensation of the system bias and scale factor can be ordered. This internal compensation increases the system accuracy over temperature and eliminates the need for the system user to perform external tempera- ture compensation.