PASCO OS-8170A Brewster’s Angle Accessory - Manual (Page 13)

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Model No. OS-8170A Brewster’s Angle Accessory
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Digits display is the same (or close to it). Adjust the Spectrophotometer Arm so the Digits
display of Reflected Light Intensity is a maximum.
11. Repeat steps 6 through 9.
12. Continue to repeat the procedure, reducing the angle of the Lens Mount by five degrees until
you reach 65°. When the reflected light intensity is approaching the minimum, record data
(press “Keep”) every one degree. When you reach 50°, change the angle by five degrees each
time until you reach about 25°.
13. Click “Stop” to end data recording.
Entering the Data
It is helpful to enter data in the table as it is collected so you can see the progression of the data
towards the minimum.
There will be two sets of data for each angle. The first set is for the perpendicular reflected light
(when the Analyzing Polarizer’s axis was horizontal), and the second set is for the parallel
reflected light (when the Analyzing Polarizer’s axis was vertical). For each angle, read the
Reflected Light Intensity and the Reference Light Intensity and enter the values into the Data
Entry Table.
1. For the first set, type the value of the Reflected Light Intensity into the “+ Polarized Light”
column. Press “Enter” and then type the Reference Light Intensity into the “+ Reference”
column. Press “Enter” after typing the value.
2. For the second set, type the value of the Reflected Light Intensity into the
“II Polarized Light” column. Press “Enter” and then type the Reference Light Intensity into
the “II Reference” column. Press “Enter” after typing the value.
Repeat the Procedure
Repeat the procedure for a different wavelength (color) laser.
Analysis
The DataStudio file that is set up for Brewster’s Angle has several built-in calculations that use
the perpendicular reflected light intensity, the parallel reflected light intensity, the reference light
intensity, and the angle of reflection. The file also has Table displays for recorded data and
entered data and a Graph display for determining Brewster’s Angle.