PASCO TD-8565 Adiabatic Gas Law Apparatus - Manual (Page 23)

© 2009 Physics Enterprises 23
Appendix A: Calibration of V
Necessary for older Adiabatic Gas Law Apparatus models, optional exercise for
newer models
If you have an older unit without the volume calibration, the following procedure will enable
you to determine the Volume/Voltage relation.
Note the diameter of the cylinder printed on the unit and record the radius,
r = ____________ cm = ______________ meters.
Drag-and-drop the Digits icon from the Displays menu onto the Voltage, Ch B(V) in the Data
menu. Open one of the stopcock valves, click the Start button and record the height (h) of
the bottom of the piston and corresponding volume voltage, V
vol
for each centimeter over
the range of motion (approximately 6–15 cm).
Table I: Cylinder height vs. Voltage
Close the Digits display.
Use your favorite linear regression method to determine the slope and intercept of this
straight-line relationship.
h = _________ × V
vol
+ ____________ (meters)
This becomes a relationship between Volume and Voltage using
Volume = π r 2 h = _________ × V
vol
+ ____________ (m 3 )
V
Vol
(Volts) h (m)
0.06
0.07
0.08
0.09
0.10
0.11
0.12
0.13
0.14
0.15