*To calculate the log or inverse of absorbance, create an equation using the
DataStudio Calculator. The linear fit and Calculator features are not available
in DataStudio Lite.
DataStudio/DS Lite Procedure
View transmittance or
absorbance results:
From the Data list, drag a colored Transmittance or
Absorbance icon to a Graph or other display.
Open the Experiment
Setup window:
On the main toolbar, click on the Setup button to
open the Experiment Setup window.
Set up the Colorimeter
to read absorbance:
In the upper right corner of the Experiment Setup
window, click on the Maximize button. Scroll to the
Colorimeter box and check the absorbance boxes.
View a linear fit*:Click on the Fit menu button. From the Fit menu,
select “Linear Fit.”
Note: Only the first data run of all four colors (red, blue, green,
orange) will correspond to the graph colors that DataStudio
displays. (This applies to either default measurements or the first
four chosen in the PASPORT Setup window).
Transmittance of Colors through a Red Solution
Activity Example (Continued): Sample Results
Viewing Results in DataStudio
CARD 2B
Activity: Transmittance and
Absorbance of Colors in Solution
Equipment Required: PS-2121 Colorimeter, DataStudio or DataStudio Lite,
PASPORT™interface connected to a USB-compatible computer, distilled water,
red (or other) food coloring, 2 cuvettes
1. Fill one cuvette with distilled water and screw the cap on securely.
2. Fill another cuvette with colored solution (i.e. 2 drops of red food coloring
and 6 ml of water). Screw on the cap, then gently rock the cuvette back
and forth to evenly mix the solution without creating bubbles.
3. Insert the cuvette containing distilled water into the cuvette holder and
tightly close the lid.
4. Plug the Colorimeter into the PASPORT interface, launch DataStudio,
and click the Start button to begin collecting data. The default graph
displays the transmittance readings for each of the four possible
wavelength settings. Click the Stop button to end data collection.
5. Open the Colorimeter lid, remove the first cuvette, and replace it with the
cuvette containing the colored solution. Repeat steps 3 and 4 to collect
data for the colored solution.
6. Examine the graph display from run #2 (the colored solution). Note
the transmittance readings at each wavelength setting. How do
they differ from transmittance readings for the distilled water?
7. To view absorbance data, click on the button to open the
PASPORT Setup window. Maximize the PASPORT Setup window
to view the Colorimeter options.
8. Uncheck each of the four transmittance boxes, and click to place an
“X” next to each of the four absorbance boxes. (Note the changed
“Data” list in the Summary bar to the left.) Close the Setup window.
9. To open a new Graph display, double click on the Graph icon in
the Data list. When the dialog box appears, select a data source to
display absorbance for a data run and wavelength. Click OK to
open Graph 2, which will display Absorbance vs. Time. (Note: If
desired, you can use a Digits display instead of a Graph.)
10. To compare absorbance values for the distilled water and colored
solution, drag the appropriate icons from the Data list to Graph 2.
Analyze which colors were absorbed or transmitted for each run
and explain your results.
800-772-8700 • 916-786-3800 • techsupp@pasco.com • www.pasco.com
®012-08158C
CARD 2A
