This report discusses the study of a 50 Hz magnetic field sensor, which can be used for continuous monitoring of high-voltage power lines. This report includes the complete development from idea to prototype to finished product by the investigating party (Ghent University - WAVES/IMEC).

A sensor with self-designed filtering, a 16-bit ADC and a microcontroller with mobile Internet capabilities was chosen. A commercially available variant (MC858) is used as the magnetic sensor element, which after research proved to be cheaper than a proprietary design. The sensor filters via hardware all signals between 10 Hz and 300 Hz and also has additional software filtering for 50 Hz signals. The range of the 0.4μT sensor goes between 0.01 μT and 70 μT, with a theoretical step size of 2 nT (for the 0.4 μT sensor). For the 100 μT sensor, the range goes from 0.1 μT to 421 μT, with a theoretical step size of 13 nT.

The report here focuses primarily on the 0.4 μT sensor, but similar reasoning and conclusions have been drawn for the 100 μT. Additional research was conducted on a combined sensor. This combined sensor reduces the cost and ensures that both sensors are now on 1 PCB and thus the hardware (ADC, microcontroller and coils) can be shared.

Therefore, after verification and calibration and long-term testing, it can be concluded that the investigating party has been able to develop a sensor that can accurately, long-term measure low magnetic fields from a 50 Hz source (i.e., high voltage line).