Simple Magnetometer

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Simple Magnetometer
As long as humans have lived on Earth, they have been fascinated by the stars and the sky. Early man looked to the sky continually for guidance and faith.

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As science progressed, we unraveled several mysteries related to the sky. From looking up to the heavens, we have gotten to the stage of space exploration. From not knowing the Earth goes around the moon, to walking on the Moon, science and technology have helped humanity quite a lot. Magnetism is a required field in science which has always fascinated humankind. This time around, we will be looking at a small school-level science project that will deal with the basics of magnetism and physics.


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Project Description

The Earth, due to the presence of the element iron in its core, produces a magnetic field of its own. Solar storms that erupt from time to time on the surface of the Sun, interact with the Earth's magnetic field and cause disturbances. These give rise to magnetic storms which leads to the misalignment of magnets and compasses. In this science project, will we look at ways to build a small magnetometer, which is a device used to sense changes in magnetic fields.

A magnetometer functions almost like a sensitive compass and is used to sense and detect slight changes in magnetic fields. The soda bottle magnetometer is a modest device that school children can make without any excess cost by using everyday items. They can be used to see the direction of magnetic fields as and when a magnetic storm occurs.

Solar Cycle and Magnetism

The Sun's activity varies as per a cycle that lasts 11 years. During these eleven years, the Earth experiences both low activity and high activity at different intervals. Periods of low activity are usually followed by years wherein we experience frequent sunspots, solar flares, and storms. All of these phenomena disrupt the Earth's magnetic field and leads to its fluctuation. A magnetometer will help students keep track of the Earth's magnetic field and can hence, be used to detect magnetic storms.

Things to Keep in Mind

  • Don't try to use an ordinary refrigerator type magnet as most of the time they are not correctly polarised and are not very strong. This will lead to inaccurate results. Therefore, make sure you get an adequately polarised North-South magnet for this project.
  • Be extra careful when you use superglue. If used in excess, the superglue will seep through the paper base, and this will result in the device getting stuck to the table.
  • Another way to make a magnetometer is via a torsion wire. Do check out this type of magnetometer as well, once you are done doing so by the method mentioned here.
Project Implementation

  • First and foremost, clean the plastic bottle thoroughly.
  • Remove all of the labels and stickers on the bottle using water and a scrubber.
  • Cut the bottle about 1/3 of the way from its top.
  • Use a compass to make a small hole in the cap.
  • Fill the bottle with sand.
  • Cut the cardboard card into a size that fits inside the bottle.
  • Use super glue to attach the magnet to the upper side of the card.
  • Again make use of super glue to glue a small piece of straw to the magnet's top surface.
  • Glue the small circular mirror to the magnet's front side.
  • Pass the thread through the straw and tie it into the bottle.
  • Use another thread to attach the previous thread to the hole in the cap.
  • Put the two parts of the bottle together such that the cardboard piece swings with the mirror right above it.
  • Tape the bottle together using the transparent tape and then glue the thread to the cap.
  • Next, place the device on a flat surface and shine a light on it, such that a spot shows up on a wall nearby.
  • Measure changes in the position of this spot to detect magnetic storms.
Concepts Used

  • Basic Physics
  • Magnetism
  • Simple Astronomy
  • Basic arts and crafts
  • Recycling
Components Required

  1. A cleaned 2-liter bottle
  2. Clean sand
  3. Thread
  4. straw
  5. Superglue
  6. Transparent and strong tape
  7. A stick
  8. A strong card
  9. Small bar magnet
  10. Small craft mirror
  11. Light Sources- Either a high-intensity lamp or a laser pointer
  12. Test tube stand and clamp to hold the light
Kit required to develop Simple Magnetometer:
Technologies you will learn by working on Simple Magnetometer:


Any Questions?