Magnetic Field Viewing Film
Magnetism is undoubtedly one of the most enigmatic phenomena of the material world; its invisible powers of attraction and repulsion fascinate and enthral us, regardless of our age. The magnetic field is the area of magnetic influence that surrounds a magnet. Even though magnetic fields are invisible to the naked eye, there are a variety of techniques to ‘see’ them.
The magnetic field viewing film is a transparent green film that lets you see the magnetic fields and pole patterns on a magnet or magnetic assembly.
Components:
- Magnets
- Magnetic Film
Working Principle:
The magnetic film is a translucent thin flexible sheet coated with nickel flakes contained in oil in micro-capsules. When a magnetic field is present, the flakes inside the spheres align along the field lines. Because of reflected light from the flakes, the alignment of the flakes, and hence the magnetic field direction, can be seen.
The film is effective for examining complex magnetic pole geometry, but it only responds to strong magnetic fields; for weak or rapidly changing magnetic fields, other approaches should be used.
This can be used for quality control, product demonstrations, reverse engineering, and teaching.
The surfaces of the flakes are reflective and appear bright when magnetic lines of force are parallel to the carrier sheet’s surface.
The flakes seem substantially darker when lines of force are perpendicular to the sheet.
When the film is placed on the pole of a magnet, it becomes darker.
The poles per inch of a magnet can be measured using magnetic field observation film and a ruler.
While humans have no way of detecting magnetic fields, many animals, such as migrating birds, dolphins, whales, and honeybees, are sensitive to the Earth’s magnetic field.
Magnetic fields have been harnessed in critical technologies thanks to our understanding of them.
The lodestone compass was the first example of this, a rock of magnetite (a naturally occurring iron mineral, Fe3O4) that aligns with the Earth’s magnetic field.
Moving magnetic fields are now used to generate electric current in both electric motors and generators. This interaction between magnetic field and metallic coil is also important in the operation of microphones and loudspeakers.
Instructions:
- To reveal the magnetic field of any form or pattern, place the flexible film directly on the magnetic material’s surface.
- A magnetic pole is indicated by dark patches, while the border line between opposite poles is indicated by light-colored lines.
You can measure the poles per inch with a ruler. - The magnetic field observation film can be rolled to fit the shape of the magnet being examined.
Links:
Playing with: Magnetic Field Viewing Film
Magnetic Viewing Film – How it Works/Demos
Magnetic Viewing Film, Looking at Zen Magnets
Magnetic Film | Magnetic Field Viewing Film
https://www.timstar.co.uk/ma150400-magnetic-field-viewing-film.html
Magnetic Field Viewing Film – Materials – Materials Library
Magnetic viewing film: visualizes magnetic poles | Goudsmit Magnetics