[PASCO Wireless Sensors]
[Dissolving Carbon Dioxide]
Mike: Hi, I'm Mike Blasberg, the Biology Education Manager at PASCO.
Barbara: And I'm Barbara Pugliese, Curriculum and Training Specialist at PASCO.
M: Today we'll be looking at the Wireless pH Sensor.
The Wireless pH Sensor has many applications for biology labs,
including environmental monitoring, looking at the role of enzymes and buffers,
diffusion, and today we'll be looking at dissolving CO2 in water.
B: First we're going to connect the sensor.
I'm going to turn it on.
M: I'm going to launch the Bluetooth menu to look for wireless devices,
and then select the pH Sensor from the list.
B: When it's connected, it flashes green.
M: From the Sensors list, we can now select the pH measurement,
and it will launch into a graph display.
Before we begin the experiment,
it's fun to ask students to make a prediction of what they think will happen
when we exhale breath into the water.
Using the Prediction tool, I'll predict that the pH will change
from about seven to about five, over 45 seconds.
B: It's a good idea to remind students
to push the cap up when you remove the probe from the solution,
so that it does not get into the test substance,
and then to rinse the probe with deionized water.
Now I'm going to place the probe into the solution,
and just going to bubble some carbon dioxide in there for about a minute.
M: All right. We'll go ahead and stop data collection.
And we can rescale the graph to get a better view of our data.
As you can see, the pH decreased
as carbon dioxide dissolved in water and created carbonic acid,
but not quite as dramatically as I had initially predicted.
We'll some basic statistics to find the minimum and maximum of our data.
B: This is the quick and easy way to get the high and low pH in your data.
M: This demo can be a nice way to introduce students
to the concept of ocean acidification or cellular respiration.
For more information on this and other wireless sensors,
please visit pasco.com/wireless.
Thanks for watching.
B: See you next time.