Measure. Analyze. Learn.
This is the Vernier Digital Radiation Monitor.
And, it's used to measure radiation.
We have a "Nuclear Radiation with Vernier" manual.
It's used in some of the more advanced chemistry manuals.
So, if your studying radioactivity, it's the tool you would use.
It measures alpha, beta, gamma, and x-ray radiation.
And, the way it works is that the radiation has to come
in through this port here, especially the alphas.
Some of the sources, like gamma rays, it's going to come
right through in any direction.
But, behind this window here, there's a little screen,
behind the window there's a mica window that
allows the alpha radiation to come through.
One thing that you want to be careful about here is that
if somebody pokes something in there, you can damage that
window, and mess that up, so you don't want to do that.
And so, behind the window there's a Geiger-Müller tube.
That, what happens is, is the radiation comes in,
it ionizes the gas, and you end up with a current that's
proportional to the amount of radiation that's coming in.
Now, the device is powered by a 9 volt battery.
So, there's just a 9 volt battery in the compartment there.
And, there's a on/off switch, and it has off, on, and audio.
And, if I actually turn it on into that audio mode, that's where
you get that clicking sound when it detects radiation there.
So we'll leave it there. So, there we heard a click.
And then, above this, there's another button here.
And, this allows you to have different settings for
when you're using this as a stand alone device.
Right now I've got it set in the total mode, and so it's actually
just measuring the total Counts as it comes through.
This middle one is Counts per minute.
And then, there's milli-Roentgens per hour.
So, you can have it set there.
You'll notice there's some other smaller print here.
And, these are some other settings, and to activate these,
you're actually going to end up turning the device on,
while holding down some of these other buttons.
And, I'm not going to go into great detail about that.
And, the reason for that is because we've got a couple of
manuals that you can get: One, this one comes with the device,
so it's kind of the general basics of how you would use this one.
It's available at the web site, but it comes with it.
But, then there's this one, and it's only available at the
website, which is a more advanced user guide for the device.
And so, some of those other settings, and how you go about
setting them up is in there.
So, I'm just going to use it in a normal use case and
how we might use it with our device here.
So, I'm going to use it to collect a little data here.
I have this glass dish.
This is called Vaseline Glass, the common name.
It turns out that this color is actually caused by uranium.
And so, when they made it, they put uranium dioxide in there,
and that's part of the color.
So, it's radioactive. It's largely an alpha source.
So, If I'm not ah, it's ok for me to be near it,
because it kind of falls off pretty rapidly here.
But, you can see, like right now, I've got it just sitting here.
And, it clicks occasionally, if you can hear that.
And, if I move it over close to
click...click...click.click.click..click.click....click
close to the dish there, then it starts to click rapidly.
So, we're getting, obviously, some more radiation.
So, I'm holding that mica window next to the dish.
So, what I would like to do, is to use this
in conjunction with the LabQuest 2, to collect data,
and maybe, look at the number of Counts in a time period.
And, to do this, I'm going to attach it to
the LabQuest via this special cable.
And so, this is the Digital Radiation Monitor Cable.
And so, it plugs into the side of the
digital radiation monitor here, so you plug it in there.
And then, it plugs into the LabQuest, in one of the digital ports.
So, I'll maybe put it in digital port one there.
Now we see the meter, and it says digital radiation in
channel 1 for the digital port.
And, right now it's giving me Counts, and it starts on 0.
But, that's the number of counts that occurred since it's
been plugged in. And so, as it goes through and clicks,
we'll get some Counts moving on there.
If we take a look at this upper right corner here,
it says "Time Based",
so it's going to look at samples as a function of time.
The rate is 0.1 samples per second, so every 10 seconds it's
going to make the actual measurement.
And, really what it's doing is counting the number of clicks
that occurred during that interval, and that's what it displays.
So, we end up with a graph of Counts as a function of time.
And so, that's happening here.
Now, a common thing that will happen sometimes is
people will see the number on the meter here, and they'll
look at the screen of the digital radiation monitor,
and they'll see that the numbers are different.
Well, this is the number of Counts that's occurred since I
plugged it in, so those numbers don’t really
relate to each other, and so, that's what's happening there.
So, we're ready to collect data.
And, what will happen is, I will press collect, and when
we do this, you're going to see a little spinning wheel.
And, that's because what's happening is it's sitting there
and collecting the data, and there's nothing to display, yet,
until that 10 seconds has elapsed.
Once 10 seconds has elapsed, it's going to display
the number of Counts that occurred during that interval.
So, I've collected data for a few minutes.
Now, I'm going to put it near my source.
And now, I'm going to slip my shield, my paper shield,
between the glass and the mica window.
So, now our data collection is complete.
And, we can take a look at our graph here.
So, there's our section when I'm furthest away from the device.
Here is the, when I put it near the device.
So, we see that how close I am to the
radioactive source here matters.
And so, the closer I am, we do that.
And then, in this point right in here, I inserted the paper shield.
And, it does seem to shield a little bit
some of the radiation reaching the detector there.
And so, we can take a look at that if we wanted to.
I might want to come in and actually look at
some of the values there.
And so, to do this, I might come in and say,
let's just highlight this region of the graph.
Maybe, I'm interested in the stats.
"What is the average over that time period?"
And so, if I go here, I end up with a
mean of 2 Counts per interval there.
And, if I go back to here, I could come and I could turn off stats,
and then highlight the region when it's near our source.
And so, now I'm getting 33, so it's definitely a lot more.
And, if I go back here, and want to do the stats, say,
for the region where I went from, say, here to here.
Then I could do the stats for that region, and I'm getting 25.
So, we did get some blocking with our paper shield.
So, we've seen a use case using it directly with the LabQuest,
a stand alone, where we measured some radiation here.
We did it a little bit a function of distance,
where we had it away from there, and brought it near there.
So, that's a typical lab that you might do.
Did a little shielding activity there.
So, that's another kind of thing that you might do.
There are shielding labs where you use different
kinds of shields, lead shields, or what not.
So, we've seen it this way.
Now I'm going to do another collection.
And, I've actually already done the collection.
I'm going to share with you what I've done.
It's a previously saved file.
And, what I did was collect data over about an hour and a half,
of this being on this source, so we'll get to see that radiation.
In the top graph, is just a graph of the Counts for time.
And, we see some variability there.
But, the bottom graph is the histogram.
So, it's telling me the frequency with which different
Counts occurred in a given time period.
And so, this might be something that
you would typically do with the radiation monitor.
So, this does require that you collect data over
quite a bit of time in order to get a good histogram.
And, you could go and fit that with a Gaussian,
and see what the distribution looks like.
To do the Gaussian, all I need to do is go up to curve fit option.
And, I have different choices here.
And, I've actually already selected the Gaussian.
So, you could that you've got some different options here.
And so, I went down, I checked "Gaussian"
I do "Try Fit", and say "OK".
And, now I have my Gaussian display.
The Vernier Digital Radiation Monitor, it's useful for being
able to measure alpha, beta, gamma, and x-ray sources.
So, if you're doing labs that involve nuclear physics,
it's definitely the sensor to use.