In this case study, Dr. Alexander Sekels of Sekels GmbH details how their MFA-110 magnetic field analysis system works with an integrated Pico oscilloscope. Their system addresses some of the difficulties of measuring magnetic fields across wide frequency ranges, particularly during Electromagnetic Compatibility (EMC) testing.

The MFA-110 magnetic field analysis system is designed for a range of applications, including electric vehicle testing and EMC certification. Read on to find out how integrating PicoScope into their system facilitated high-precision AC magnetic field monitoring, FFT analysis and gapless data acquisition in a portable and USB-powered solution.

Introduction

In industries where magnetic field safety and compliance are paramount, precise and reliable measurement tools are essential. The MFA-110 by Sekels GmbH provides a comprehensive solution for measuring and analyzing magnetic fields across the frequency range between 1 Hz and 400 kHz. It combines search coil sensors, high-resolution oscilloscopes by Pico Technology, and Fourier transform-based analysis to deliver critical insights into magnetic field behavior.

The system is designed to accommodate both continuous measurement scenarios, such as monitoring magnetic field exposure during the test drive of electric vehicles, and structured procedures with predefined measurement points for repetitive tasks.

By leveraging oscilloscopes by Pico Technology, the system ensures gapless acquisition and storage of raw data, allowing users to evaluate compliance against various standards regarding magnetic fields, even as the standards evolve.

Additionally, the detailed frequency analysis provided by the FFT spectrum enables the identification of critical frequencies that may require further investigation. This level of insight is not typically available in systems that only provide a single exposure index, which can obscure the root causes of electromagnetic compatibility issues.

Background

Magnetic fields are an inherent consequence of electric currents, which are present in almost all modern electronic devices and car components. Their intensity and frequency can vary widely, potentially posing risks to humans and sensitive equipment. Regulatory frameworks worldwide enforce limits on magnetic field exposure, compelling manufacturers and operators to ensure compliance.

Details of the System

The MFA-110 combines multiple components to deliver comprehensive magnetic field analysis:

The 3D Isotropic Probe is equipped with three search coils, enabling the capture of magnetic field data across three orthogonal axes for both vectorial and scalar analysis.

The Main Unit processes sensor signals using preamplifiers and a PicoScope® oscilloscope. The oscilloscope features four channels — three dedicated to sampling the search coil signals simultaneously and one available for external signals. This additional channel allows users to correlate external signals with the measured magnetic field. Furthermore, both the main unit and the PicoScope® oscilloscope are powered solely via USB, making the entire system portable.

The M-Stream Software controls the PicoScope® oscilloscope through its API, handles data storage and analysis, and evaluates the results against a wide range of established or user-defined electromagnetic compatibility standards.

Measurement Setup and Strategy

The primary objective in integrating PicoScope® oscilloscopes into the MFA-110 system was to enhance its capability to continuously measure, stream and store raw voltage signals. This feature enables long-time gapless measurements of up to several hours, while offering the flexibility to analyze the data according to multiple established EMC standards — current or future — without the need for additional hardware.

Sekels integrates PicoScope for high-resolution measurement of AC magnetic fields 2

Data Processing and Results

Sekels integrates PicoScope for high-resolution measurement of AC magnetic fields 3

Measurement data is presented both as raw voltage signals and as processed outputs, utilizing FFT algorithms to calculate the exposure index and to generate a detailed frequency spectrum. This spectrum helps identifying critical frequencies that may need further investigations of their root causes.

The M-Stream software supports custom reporting and seamless integration with external tools like Microsoft Excel for advanced processing.

Conclusion

The MFA-110 system provides a robust solution for measuring and analyzing magnetic fields in a wide range of applications. By combining 3D isotropic probes, Pico Technology oscilloscopes, and M-Stream software, it enables reliable, gapless data acquisition and detailed frequency analysis.

This collaboration demonstrates how advanced tools like PicoScope® oscilloscopes can elevate specialized systems, addressing the needs of industries where magnetic field safety and compliance are critical.