PASCO ME-6667 EcoChamber - Manual (Page 2)

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The unique design of the EcoChamber allows the system to
remain closed, which allows for measurements to have a minimal
impact on the system. Environmental science probes can be used
to actively measure variables in the ecosystem model. A syringe
and tubing are included to extract water for chemical testing,
replenished water without opening the system, and inject pollut-
ants for chamber manipulation.
Equipment Set-up
1. Fill the EcoChamber according to the instructions in the lab
you are performing.
2. Select the sensors and interface that you intend to use for the
experiment.
3. Place the lid onto the EcoChamber.
4. Insert large stoppers with holes into the holes in the lid.
5. Insert probes into the holes in the stoppers.
6. Use solid stoppers to fill any unused holes.
7. Connect the sensors to Xplorer GLX or other interface.
Sensor Calibration
Calibrate sensors prior to using them in an experiment. Refer to
the documentation provided with each sensor for calibration
instructions.
Note: In some cases, sensors do not require calibration. If, for example,
you wish to measure only relative dissolved oxygen changes, the sensor
does not to be calibrated.
Xplorer GLX Set-up
Note: The interface set-up and data collection instructions and sample
data in this and the following sections apply to the Xplorer GLX datalog-
ger. Other data collection systems can also be used.
EcoChamber experiments are typically long-term experiments. If
data is collected at the default rate, the volume of information
may fill the memory of the GLX before the end of the experi-
ment. To prevent the Xplorer GLX from ending the experiment
early, change the sample rate of every sensor.
1. Press
h+I to access the Sensors screen. The sensors
currently connected to the Xplorer GLX will show across the
top of the screen. The Sample Rate Unit will be highlighted
for the sensor in port 1.
2. Press
c to see the available sample rate units for that sen-
sor. Highlight “minutes” using the arrow keys and press
c.
3. Use the arrow keys to highlight Sample Rate and press
c.
Change the sample rate to 1, 2, or 5 minutes between sam-
ples.
4. Use the arrow keys to highlight the sensor in port 2. Press
c to select that sensor, and repeat steps 2 and 3 to change
the sample rate. Do this for the remaining sensors.
Data Collection
1. Ensure that the GLX is in Continuous data collection mode.
a. Press
h+I to access the Sensors screen.
b. Press
F to access the Mode menu. If necessary, use
the arrow keys to select Continuous and press
c.
2. With the sensors in place, press
s to begin recording data.
3. Allow the experiment to run for the specified time. Do not
bump or jar the EcoChamber, as this may cause the sensors
to record erratically.
4. Press
s to stop collecting data.
Data Analysis
Graphs showing two variables changing over time are most valu-
able in the EcoChamber experiments because they show the rela-
tionship between related quantities, such as oxygen and carbon
dioxide concentrations, and how these relationships changes over
time.
Example Activities
Aerobic Respiration and Fermentation in Yeast Place
the EcoChamber on a magnetic stirrer. Put a stir bar in the bottom
of the chamber. Pour 100 ml of 20% yeast solution and 500 ml of
0.5 M sucrose solution into the chamber. Place an oxygen gas
sensor, a carbon dioxide gas sensor and an ethanol gas sensor into
holes in the lid. Put the lid on the chamber and press to tightly
seal the chamber. Make sure that all other holes in the
EcoChamber are filled with stoppers. Turn on the stirrer to a
medium setting and begin collecting data. Observe oxygen, car-
bon dioxide, and ethanol levels for 60 minutes.
Measuring Photosynthesis Place a small potted plant in
the bottom of the EcoChamber. Put an oxygen gas sensor and a
carbon dioxide gas sensor into the holes in the lid. Place the lid
on the chamber and press firmly to seal. Make sure that all other
holes in the lid are filled with stoppers. Begin collecting data.
Observe photosynthesis by measuring oxygen production and
carbon dioxide consumption for 30 to 60 minutes.
Effects of Temperature on Photosynthetic Activity
Repeat the experiment above, but place a floodlight in front of
the chamber. Turn the light on for 20 minutes. After 20 minutes,