Measure. Analyze. Learn.
This is the Magnetic Field Sensor.
It is used in several of our different manuals.
And, it shows up in physics, middle school.
And, it's a useful device to have.
The sensitive part of the detector is right down here at the tip.
What it does is, it measure magnetic fields
that come in perpendicular to this white tip.
It's what we call a hall probe.
So what you want to do is move this relative to a magnet,
and you could measure maybe things about the strength
of the magnetic field as a function of distance from the magnet.
There is an nice lab where you use electromagnets,
where you use an electromagnet vary the number
of turns on a nail, and to be able to do that.
This tip down here is also flexible.
So, we can move it perpendicular to the original direction.
There's some labs where you may want to do that.
You have it set in one setting, and then you move it,
and look what happens to the strength of the field when you
change the orientation of the sensor.
This is a multi-range sensor.
And so, there is a sensitivity switch here.
So, there is a high and low amplification setting.
The high amplification is actually the smallest number.
And so, if you are looking at a fairly weak magnet,
you can use high amplification.
And, if you have a strong magnet,
you can move it to the lower amplification.
So it's a twenty-fold difference in the amplification there.
So now, we're ready to collect some data.
And I have a magnet here.
It's just an old speaker.
And, I'm just going to make some measurements around it,
just to give us a reading there.
So, I'm going to plug it in.
It's an analog sensor, so we plug it into the analog port there.
I'm going to collect some data.
And, what I'm going to do is move the magnetic field sensor
closer to the magnet, and then move it away from the magnet.
And, I'm interested in looking at this as a time graph.
The default setting for the device
is a 10 second time based collection.
And, to begin collection,
I am going to press the start button here.
And, I move the sensor closer to the magnet;
I move it away from the magnet.
And then when the run is complete
it is going to auto scale the graph.
And, what we're looking at there is the strength
of the magnetic field relative to its position.
And so as I got closer, I ended up with
a larger negative number, in this case.
And, as I moved away it got smaller.
So, again, this sensor is used across the curriculum.
It's very good to have.
It allows student to measure magnetic fields
in a way they haven't done before.
They've discussed north and south,
but they haven't discussed the actual quantitative
measurement of the magnetic field strength.