Hysteresis in Hall Probe Calibration Curve

[TheDestroyer]

Hysteresis loop in probe??

Hello guys,

I have done the Magneto-optical Kerr effect experiment, studying the hysteresis loop over some pieces of ferro- and ferri-magnetic pieces of metals (CDs and MiniCDs).

The problem is the following, we first started by creating the calibration curve for the experiment using Hall probe, but the very weird thing that I couldn't understand is that there has been hysteresis for this curve too, while it should be a very sharp line. I have included the graph.

Can anyone explain the reason?

Thank you in advance

 

[TheDestroyer]

Come on guys! is it a difficult issue? help please!

 

[Bob S]

Is the vertical scale on your plot in kilogauss? Are you using a magnet with iron in it? Are you taking into account the hysteresis of your magnet? Are you using an Analog Devices or an AllegroMicro Hall Effect sensor? If you don't believe the Hall probe, then you could use an integrator coil (Faraday induced voltage) into a voltage integrator circuit.

 

[TheDestroyer]

10 in the graph denotes 1 Tesla, but can the iron in the magnet cause such a thing?

 

[Bob S]

10 in the graph denotes 1 Tesla, but can the iron in the magnet cause such a thing?

Exactly. One Tesla equals 10 kilogauss, so that explains the curve in the plot. The iron is beginning to saturate somewhere in the magnetic circuit. The small hysteresis seen in the loop is due to hysteresis in the iron in the magnet.

 

[TheDestroyer]

Thank you :)

if someone has a different explanation or a discussion to start, I would appreciate it :)