2. The
experiment should be viewable most of the time,
but operable with power only part of the time.
See below for a schedule of available dates and
times. You may see in the web camera window a
sign indicating that the power is turned off,
otherwise the power will be on. Even with the
power off you can learn to operate the
experiment, but without observing boiling.
3. If you choose
to register, please enter your first and last
name, institution, and email address, and then
click GO. Otherwise click Bypass Registration
to go directly to the experiment.
4. When
connected you will see two windows, one the
webcam window and the second the front panel of
the LabVIEW VI, heata01.vi. You can shift the
boundary between the windows to the right to see
more of the panel. The webcam window will show
a glass tee with a resistance heated rod
immersed in water, and also a panel meter
displaying the surface temperature of the rod in
Celsius. The tilt/pan/zoom controls surrounding
the webcam window can be used to vary the view.
5. A small box
on the VI panel can be used to set the name of
the file to which the run data (main index,
percent power, surface temperature, and power in
Watts). The default file name is aa01.xls, but
other Excel (.xls) file names can be chosen.
6. The VI panel
shows instructions, similar to these, for
operating the experiment. To begin, right click
the gray area and select Request Control. The
response will be Control Granted. Click on the
white Run arrow at the upper left to begin the
run. A full run will last 200 seconds,
equivalent to a main index of 100. Then use the
cursor to set the percent power, from 0 to 100
percent. Note: You must use Ctrl-Bkspc,
instead of Backspace, to erase the existing
numbers. The power level can be changed at any
point in the run. As the run progresses the
surface temperature (Celsius) is visible on the
panel meter, and is also plotted on the panel
and shown on the VI panel. The camera will show
vigorous nucleate boiling on the rod, and
two-phase flow in the glass tube above the
heated rod. In general the surface temperature
will increase with the power level, and a number
of power levels can be used in a single run,
since the time needed to achieve a new steady
state is only a few seconds.
7. When the run
ends a small window will open and the data file
can be saved (replaced) in folder zzheat on the
host computer. At this point you can change the
file name and make another run, or exit. To
exit, right click on a gray area and click
Release Control. Then click X exit from the
panel and camera windows.
