Quantum Magnetometry for Material Testing

Optically pumped zero-field magnetometers (OPM) are extremely sensitive to small variations in magnetic stray fields. However, their spatial resolution limits their application in non-destructive test-ing. With the help of flux guides these challenges can be overcome. This paper shows an example how the combination of OPM and flux guide can be used to measure magnetic stray fields of partial penetration weld seams in ferromagnetic steel sheets from the bottom side.