NASA | Fluxgate Magnetometry

A flex gate magnetometer functions like a compass but uses electromagnets to measure magnetic fields. It is built using a ferromagnetic metal bar wrapped with a coil of wire. By running an electric current through the coil, the bar becomes magnetized. Reversing the current reverses the magnetic field direction, and repeating this process cancels out the directions. However, an external magnetic field disrupts this balance, allowing measurement. Multiple sensors can be combined to measure magnetic fields in three dimensions.

How does a flex gate magnetometer differ from a traditional compass?

• It measures temperature changes.

• It uses a liquid-filled chamber.

• It uses a spinning needle to measure magnetic fields.

• It uses electromagnets instead of a needle.

What is the first step in building a flex gate magnetometer?

• Attaching a spinning needle.

• Using a liquid-filled chamber.

• Measuring temperature changes.

• Starting with a bar of ferromagnetic metal.

What happens when you reverse the current in the coil of a flex gate magnetometer?

• The magnetic field strengthens.

• The magnetic field changes color.

• The magnetic field reverses direction.

• The magnetic field disappears.

How does an external magnetic field affect the magnetometer's internal field?

• It throws the internal field out of balance.

• It strengthens the internal field.

• It has no effect on the internal field.

• It balances the internal field.

What is the advantage of using multiple flex gate sensors?

• They can measure a magnetic field in three dimensions.

• They can reduce the size of the device.

• They can measure temperature changes.

• They can increase the speed of measurement.