Magnetic Field Measurements Figure 4

1) Magnetic Field Sensor

Turn on the computer and login to the network. Run the "Internet Explorer" web browser and select "CapMagnetism" from the favorites menu. This will run software that works with the computer interface and has been setup to measure magnetic fields with the magnetic field sensor, the amplifier set to high.

For your work, you will need to scale the computer data graphs to suit your measurements. Also zero has not been set (absolute measurement can not be made, only relative measurements).

Test your sensor and software to obtain an understanding of how it functions. Notice the sensor is directional and readings a very sensitive to the probes orientation in 3-space. The magnetic field is measured perpendicular to the white dot on the sensor. Test the sensor operation in the field of a permanent magnet.

2) Earth's magnetic field and inclination

Set the amplifier to high and hold the probe away from possible magnetic fields and any metal. Measure earth's magnetic field by orienting the probe for an maximum reading and then reversing the probe for a maximum negative reading (software scaling will need to be adjusted). Earth's field will be half the difference. By taking data as the difference in reversed probe orientation will account for any zero offset and asymmetries in the experiment.

If the sensor tube is held vertically and rotated until the maximum reading is found, magnetic north will be perpendicular to the white sensor dot. The magnetic inclination in the area can be found by holding the tube so that the white dot is facing north and rotating the sensor end of the tube down until the reading reaches a maximum. Determine the magnetic inclination (the angle from horizontal) of the earth's field at your bench. (Your measured field strength and inclination may be strongly influenced by surroundings including in floors and walls).