32
8.
Click the
Scan
button or select
Scan | Solution
from the menu. The absorbance value will appear next
to the concentration for Solution #1. At any point, you can select
Edit | Clear
from the menu to clear
the dialog box of all data.
9.
Take Solution #1 out of the cuvette holder and put in another standard solution with the next highest
known concentration. Enter the known concentration of the standard solution in the chart in the
Concentration
column, next to
Solution #2
.
10.
Click the
Scan
button or select
Scan | Solution
from the menu. The absorbance value will appear next
to the concentration for Solution #2.
11.
You may continue to scan solutions with known concentrations. You must scan at least 2 in order to
achieve a calibration curve.
12.
When you have completed taking scans of your solutions with known concentrations, click the
View
Calibration Curve
button. You will then have the
Intercept
and
Slope
of your curve. The Slope is the
ε
necessary to compute Beer’s Law and to find the
unknown
concentration of a solution.
13.
At this time, you may also select a label for your concentration values, such at
Moles per Liter
, in the
Concentration Units
box. This is only a label and does not affect the data in any way.
14.
Select
Edit | Show Legend
from the menu to display the legend for the calibration curve. The legend
allows you to choose a plot design, point style, line style, line width and plot color. Select
Edit | Show
Palette
from the menu to display a variety of options for configuring the curve. The palette provides
features such as autoscaling, graph formatting, value precision, mode mapping, and graph positioning.
15.
You can select
File | Print
from the menu for the dialog box to print the dialog box. To save the
current calibration curve data, select
File | Save
from the menu for the dialog box.
16.
Select
File | Close
from the menu for the dialog box to close this dialog box and return to the
main window.
17.
When a message box asks if you would like to use this calibration curve when calculating
concentration values, select
Yes
.
18.
Now that you are back in the main display window, place the solution with the
unknown
concentration
of a substance in the cuvette holder.
19.
Under
Mode of Operation
, select
Concentration
. Click the
Scan
button to receive your
concentration values.
