Berlin 2024 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

MA: Fachverband Magnetismus

MA 47: Poster III

MA 47.14: Poster

Thursday, March 21, 2024, 15:00–18:00, Poster D

Quantitative magneto optical stray field characterization for magnetic scales — •Nils Magin and Sibylle Sievers — Physikalisch-Technische Bundesanstalt, Braunschweig, Germany

We present the application of magneto optical indicator film based magnetic field measurements to the characterization of magnetic scales. Magnetic scales with incremental pole pattern are combined with Hall or magneto-resistive sensors to build robust magnetic encoders. However, quality control of these scales requires a spatially resolved quantitative analysis of their stray field distribution, which is not possible with the typically several 100 µm wide encoder sensors.

MOIF is a fast (sub second resolution) imaging technique that allows a one-shot characterization and thus high throughput of samples with areas of several square centimeters. It combines the capability to detect fields from the millitesla (mT) to the tesla (T) range with sub-micron spatial resolution. Additionally, it can be used for rough samples without the need for surface treatments.

We here apply magneto-optical indicator film measurements to the characterization of the stray field distribution of magnetic scales and propose procedures to derive parameters of magnetic scales like pole width and field amplitude. The calibration and uncertainty of MOIF based characterizations is discussed.

This project (EMPIR 20SIP04 qMOIF) has received funding from the EMPIR programme co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme.

Keywords: MOIF; magnetic scales; magnetic sensors; quantitativ field measurements; MOIF calibration