Green Magnetic Viewing Film 4x6 | Cool Magnets Science Kit | Magnetic Field Detector & Visual Aid for Physics Education | Ideal for Research & Magnetism Demonstrations

The same film is used by professionals such as engineers, developers and researchers to find out the magnetic field distribution when a group of magnets is involved.

It is also used in the manufacturing industry to form the internal defect of a steel part in conjunction with an X-ray machine.

The green foil contains millions of nano magnetic particles that can rotate freely when you are near a steel object or a permanent magnet.

When the magnetic particles change their orientation, the reflection rate of the light also changes to the magnetic field below.

This is why the film changes shades when a magnetic field is applied.

The film becomes darker when the magnetic field lines are perpendicular to the surface, and brighter when the field lines are horizontal, i.e.

across the surface.