Magnetic field measurements on disc magnets

[Physikfan]

The magnetic flux density was measured at the surface of permanent disc magnets by a Hall probe:

Disc magnet 30mm diameter, height 15 mm, NdFeB:




Results:

Disc center 0.44 T
1 cm distance 0.2 T
2 cm distance 0.06 T
Edge up to 0.5 T
Side part of the disc (curved) 0.06 T

Disc magnet 45 mm diameter, height 30 mm, NdFeB:




Results:

Disc center 0.52 T
1 cm distance 0.28 T
2 cm distance 0.14 T
edge up to 0.6 T
side part of the disc (curved) 0.06 T

[FrankBuss]

That's strong, but show as the Hall probe please, and the measurement system.

[Physikfan]

Here you can see the Hall probe as well as the Tesla meter:

[FrankBuss]

Why does the Tesla meter show kg?

But this gives me an idea: would it be possible with a defined test object and something like a spring scale to calculate the magnetic field strength? Like you pull the spring scale as strong just before the test object gets lose from the magnet, then read the value. Could be even used the measure the field in some distance with spacers.

[Physikfan]

kG means kiloGauss
1 Tesla = 10**4 Gauss

[FrankBuss]

Right, this makes sense.

It is confusing that there are so many things "g" can mean, like gram, gravity or Gauss, if written with a capital G. But I guess usually it is clear from context. And kg wouldn't make sense for acceleration, except maybe near the big black hole in the center of our galaxy.

[VintageNut]

Here you can see the Hall probe as well as the Tesla meter:

Does the meter/probe combination have a specification for uncertainty?

[Physikfan]

The uncertainty of the meter/probe combination is about +- 5%.

[Doctorandus_P]

Some time ago I also wanted to buy a Gauss meter, but it was not important enough to invest > EUR 50.
Second option was of course to build my own.
Problem was however that all those cheap lineair Hall sensors are too sensitive.
Take for example the AO3503
http://p.globalsources.com/IMAGES/PDT/SPEC/229/K1011923229.pdf

It's lineair section only goes up to 90mT which is about 2 orders of magnitude too sensitive for measuring normal magnets from close up. All the cheap sensors I could find were much too sensitive.

[Physikfan]

Using this meter/probe combination I have 4 measuring ranges:
3 mT, 30 mT, 300mT and 3 T.