[PASCO Wireless Sensors]
[Wireless Colorimeter and Turbidity Sensor Overview]
Hi, I'm Tom Loschiavo, Education Manager here at PASCO scientific.
I'm here today to introduce
the Wireless Colorimeter and Turbidity Sensor.
The colorimeter is great for measuring colored solutions,
and the turbidity sensor is great for measuring the quality of water samples.
Let's take a look at what's in the box.
When I open the box,
there is a Wireless Colorimeter and Turbidity Sensor.
There are cuvettes and two cuvette racks.
There are 10 cuvettes total --
-- 6 of them for use with the colorimeter
and 4 are four clear slides for use with the turbidity sensor.
There is a 100 NTU standard for calibrating the turbidity sensor.
And there is a USB cable for charging.
First we are going to focus on the colorimeter.
To do that, I'm going to connect it to my software.
I'm using SPARKvue software.
I'm going to turn on the colorimeter sensor,
and I'm going to connect it via Bluetooth.
Using the colorimeter, I'm going to test these prepared cuvettes.
My device pops up.
I'm going to connect to it.
After it connects,
you'll notice that a prompt appears to calibrate the sensor.
Calibration is an important part for colorimetry and turbidity.
It is recommended that you calibrate each time,
and it is recommended that you instruct students to do so.
If you are in a hurry, or if you know you calibrated very recently,
you can hit Cancel, because the calibration is stored right on the device.
But I'm going to walk through the calibration.
So I hit Calibrate.
I can calibrate either turbidity or colorimetry.
In this case, I want to calibrate my colorimeter
And it instructs me on what to do.
I'm going to insert a blank cuvette, which is a cuvette with the solvent.
I'm going to use the cuvettes that have ridges on the sides
so that I don't touch the cuvette where the light is going to go through.
I'll put that into the colorimeter,
so the light goes through the clear side over to the detector.
I know that the detector is over here because of the rainbow.
I'm going to put that in.
I'm going to hit Calibrate.
Once it's calibrated, I get this green check mark --
A nice indicator for students and for you to know that something happened --
-- and this is calibrated.
I'm going to hit Done.
Since I calibrated the colorimeter,
my colorimeter measurements pop up on the Home screen.
They're reading zeros for the absorbance
and 100% for the transmittance,
which is what you would expect for the calibration.
Now I do want to introduce this with a Quick Start lab.
Over here under SPARKlabs,
there are Quick Start labs that are sensor-specific.
If I click on this Quick Start tab,
then I get a couple of Quick Start labs that are only for this Wireless Colorimeter.
The first one is a great introduction, that is "Absorbence and Transmittance".
I click on that then a page pops up.
It's a bar meter display where my absorbances of the different wavelengths
are across the bottom and the absorbance value is on the y-axis.
Those absorbance values on the bottom are in increasing wavelength order.
If I hit Start, I see pretty much nothing.
I see zero across because I have blank in there.
Now we can test some colored solutions.
You do want to make sure that you're wiping those cuvettes
in between when you pop them in.
There's my blue solution.
I'm going to use a graph tool to auto-scale that.
I'm going to put the number display, Show Values, onto those bars also.
Now you notice something interesting.
This is a great thing to teach your students and to have them figure out.
You'll notice that the blue solution does not absorb mostly blue light.
It actually absorbs mostly orange light.
One of the things we want to teach with the colorimeter
is that the complementary colors are what's important
when you're talking about absorbance.
If you think about a color wheel --
-- red, orange, yellow, green, blue, and violet --
-- blue and orange are complementary colors.
The reason this appears blue is because it's not absorbing blue,
it's absorbing mostly the complementary color to blue, which is orange.
We can look at that if we compare a couple of other samples.
If I pop in a red solution,
we'll see that's absorbing mostly the other end of the spectrum,
the blues and greens.
If I put in a yellow solution,
it's absorbing mostly violet.
Again, thinking about that color wheel.
Finally, if I put in a green solution...
This one is interesting because it's absorbing lots of oranges and reds
and it's absorbing lots of violet.
That's because that green solution is a mixture of blue and yellow.
So I'm getting both of those absorbance values in that mixture.
We're going to reset and we're going to focus on the turbidity measurement
of the Wireless Colorimeter and Turbidity Sensor.
Now we're going to focus on the turbidity measurement
of the Wireless Colorimeter and Turbidity Sensor.
We're going to try to determine the turbidity of this unknown sample.
To do that, we are going to reconnect our sensor to SPARKvue.
Since we have reset and reconnected,
it is going to prompt us to calibrate again.
That's good because calibration for turbidity
is just as important as it is for colorimetry.
I'm going to go in.
Since I'm prompted, I'm going to hit Calibrate.
It is going to pop up the turbidity sensor or colorimeter.
I want to make sure I'm calibrating with the turbidity sensor
Now, it's going to ask me to calibrate with two things.
I'm doing a two-point calibration with my blank
and a 100 NTU standard.
My blank is distilled water, which is a zero NTU standard.
This is my 100 NTU standard,
and that came from this bottle from the Colorimeter and Turbidity Sensor box.
If you notice when I'm doing turbidity,
you want to make sure you're using the four-sided, clear cuvettes.
That is because for the turbidity measurement
the light is coming perpendicular to the detector.
I want to use this four-sided, clear cuvette.
I'm going to put in my blank, or my zero NTU standard.
I'm going to hit Calibrate.
I get that check, so I know that the calibration is complete.
I'm going to take my standard, my 100 NTU standard,
I'm going to make sure it is mixed.
There are instructions for mixing in the reference manual.
Make sure the slides are clear and put that in.
I'm going to Calibrate.
I get that check again, so I know calibration is complete.
I'm going to hit Done.
Now on my Home screen,
I want to make sure I'm looking at the turbidity sensor measurements.
I'm going to close the Colorimeter and
make sure Turbidity is open.
Now I'm getting 99.5 NTU, about 100 that I standardized with.
That's great, my calibration took.
Now I want to measure my turbidity of the unknown.
To do that -- there isn't a Quick Start for this.
I'm going to do a Show Path because I just need the measurement itself.
I just want to look at the digits.
I'm going to click on Turbidity.
I get a graph right away.
I'm going to use this arrow to have a nice big display of my NTU.
I'm still reading about a 100 for my standard, which is great.
I'm going to, again, make sure this is nice and mixed
according to the instructions.
Make sure those slides are clear and clean.
Put that in.
Now I'm measuring about 58 NTUs for my unknown.
The detector ranges from 0 to 400 NTUs with an accuracy of about 5%.
If you are over 400, you will want to dilute your sample.
This Wireless Colorimeter and Turbidity Sensor
is great for looking at colored solutions.
Applications include looking at concentration and color,
and then also looking at reaction kinetics:
we can see dyes fading or reactants change in color over time.
The turbidity measurements are great
for looking at the quality of water in terms of turbidity.
If you want to learn more about this sensor
and any of our other wireless sensors,
go to pasco.com/wireless.