System Testing
The system had to perform two main functions. The first was that it must remain
light proof throughout the experiment. The second was that it must provide a
temperature-controlled environment. Two tests were preformed on the Yeast-cultivator
to verify that it meet these requirements.
The systems' temperature control was
tested by submerging it in an ice bath. The ice bath was used to simulate the
cold temperatures of the magnet bore. The yeast was simulated with powdered
cheese mixed with water. During this test the temperatures of the sample and
water bath were monitored. The sample started with a temperature of 21 degrees
Celsius and the water bath temperature started at 47 degrees Celsius. The first
goal of this test was to bring the sample to 23 degrees Celsius, the temperature
at which it should be during the actual experiment. The sample reached this
temperature after approximately twenty-five minutes. The next goal was to maintain
the target temperature of 23 degrees for the sample. This was not easily accomplished
at first. When the sample got to its target temperature it tried to over shoot
it due to the high water bath temperature. The thermal calculations suggested
a water bath temperature of about 31 degrees Celsius. At the time the target
temperature, for the sample, was reached the water bath was at 48 degrees Celsius.
The water bath temperature had to brought down to 31 degrees Celsius to see
if the sample would remain at 23 degrees Celsius. This was done by not pumping
the outlet water from the system back into the water bath. This water
was replaced with cooler however this process was very tedious because
the pump was heating the water bath by 0.1 degrees Celsius every three minutes.
The best way to maintain the required water bath temperature would be to
chill with ice and discard the return water.
The second test performed on the system was to ensure the test chamber was
light tight. For this test the use of a spectrometer was required. An appointment
was setup with Dr. Wei at the NHMFL to use his spectrometer. Again the system
was assembled, as it would be for an actual yeast experiment. The spectrometer
was first calibrated to determine its' dark current. After this the
spectrometer was then 'zeroed-out' to give the proper reference for the light
measurements. The fiber optic cable was attached to the spectrometer and several
light readings were taken. From the initial measurement it appeared as if the
fiber optic cable was not attached properly because no light was detected.
After testing the cable separately and inserting a light into the test chamber,
to get a non-zero measurement, it was determined that the system was completely dark.
Last Revised: 2000-12-20