Now Available: Non-Destructive Hardness Testing

May 1, 2017 by
Marco Marino

After multiple years of development, we now present the hardness testing device QASS µmagnetic, which is outfitted with a completely new micromagnetic testing method. This system allows contactless hardness testing. It combines a highly sensitive magnetic sensor with the company-owned spectral analysis, the pattern recognition, and a fully automated evaluation with the help of programmable (MATLAB-like) analysis tools.


This measuring technique is based on Barkhausen noise, which is erratic changes in the magnetic field when magnetizing iron, and is combined with a very high sampling rate and the real-time spectral analysis. This way the device can measure the hardness of ferromagnetic components, for example, even under high noise conditions. The correlation between the erratic reversal of magnetization and the hardness of steel components has been known for a long time.

QASS µmagnetic measures hardness non-destructively and 100 percent, in real-time. Portions of the component are magnetically reversed and, at the same time, the magnetic properties are measured. From this data, the software can deduce the changes in hardness due to different magnetic properties and gives results qualified for industry 4.0.

The spectral depiction in high speed minimizes sources of error in production processes, like external magnetic fields or eddy currents. The usable signal, which under production conditions is usually weak and noisy, is optimized and the results become reproducible through our 3D pattern recognition.

Ready for Big-Data and Industry 4.0​

The device collects millions of sensor data per second and processes this data in real-time. The measuring system makes the results visible in a 3D-topology on the monitor. Cognitive measuring means understanding measuring: adapted to your process, the system recognizes on its own, when tolerance thresholds are exceeded. The software can, in this way, distinguish between components, which are OK, and parts, which mechanical parameters have exceeded thresholds.

Hardness testing examples: grinding and hard tuning​

Everywhere, where hardness is measured, the system can be used. As one of the many applications the manufacturer mentions grinding and hard turning processes. The recognition of new hardening zones on the complete surface is enabled in real-time. The contactless measurement enables this in many processes. Even for continuously introduced material, like wire and plates, the deviations in hardness or consistency in the whole material can be controlled during the process and are documented. Testable are all components, which consist of ferromagnetic materials. The system can be easily retrofitted into any existing production chain.

The next advancement is already in development: A measurement procedure to determine the hardening depth.

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