1. WHAT IS DATA LOGGER ?
A data logger is a basic box capable of picking up and storing signals from sensors. For
ease of use they generally have a minimum number of displays and controls and their portability
enables remote data logging for example logging data away from the computer. Data loggers are
either fitted with an internal battery that is rechargeable or use regular alkaline batteries. Some
may also have external power supplies. Most data loggers store data in non-volatile memory,
which means the data will not be lost if the power supply fails. It is important to note that low
battery charge may cause some data loggers to behave erratically. A cable or docking station is
normally provided to facilitate a connection to a computer or other hardware. Data loggers can
also make use of Bluetooth or Infra red communication to transfer data.
A sensor is a device that senses surrounding data which is then recorded by a data logger.
Generally, four or more sensors are capable of being connected to a data logger, depending on
the model. There are over 40 different sensors available, including light, temperature, pressure,
conductivity, motion, humidity, oxygen, carbon dioxide, pH, voltage, altitude, dew point, wind
speed, and wind chill.

2. ENGAGING
Plants make sugar, storing the energy of the sun into chemical energy, by the process of
photosynthesis. When they require energy, they can tap the stored energy in sugar by a process
called cellular respiration. Photosynthesis is the process whereby the radiant energy of the sun is
converted into chemical potential energy of organic molecules. This process is responsible for
present life on this planet ‐ it provides food, and therefore the energy source for nearly all
living things. The utilization of light energy as an energy source is found only in certain
photosynthetic organisms; a few bacteria, some protists, and, of course, plants. Plants, in addition
to their formation of high‐energy foodstuffs from light energy, water, and carbon dioxide, also
produce oxygen, a gas essential for our life. The process of photosynthesis involves the use of
light energy to convert carbon dioxide and water into sugar, oxygen, and other organic
compounds. This process is often summarized by the following reaction:
6 H2O + 6 CO2 + light energy → C6H12O6 + 6 O2
Cellular respiration refers to the process of converting the chemical energy of organic molecules
into a form immediately usable by organisms. Glucose may be oxidized completely if sufficient
oxygen is available by the following equation:
C6H12O6 + 6 O2 → 6 H2O + 6 CO2 + energy
All organisms, including plants and animals, oxidize glucose for energy. Often, this energy is
used to convert ADP and phosphate into ATP.
For this experiment, were going to detect what is the gas produced/consumed by the
plant as the result of photosynthesis and what is the amount of gas produced/consumed during
that time using the gas sensor. Two types of gas sensor, that is oxygen gas sensor and carbon
dioxide gas sensor will be used.
The oxygen oxygen and carbon dioxide sensors will be used to measure any change in
the concentration of those gases in the presence of a plant specimen. The sensors are connected
to a hub called Lab Quest Mini that connects to a computer and allows you to see and record in
real time the measurement of oxygen in the chamber. This apparatus is sensitive and expensive,
so please use caution when experimenting. The software you will use with this set up is called
Lab Pro/CBL 2 and it will record data and create a graph while you experiment.

3. The oxygen sensor continually measures the oxygen concentration using a lead anode, a
gold cathode, and an electrolytic solution which carries a current produced in proportion to the
oxygen concentration, by the reduction of the oxygen molecules. The oxygen sensor must be
kept upright or it will not work properly and could be damaged. It is the vertical sensor seen in
the photo of your apparatus.
The carbon dioxide sensor is the horizontal sensor and uses infra‐red emission to
measure the gas concentration in the tube between one end of the sensor tube where the beam is
generated and the other end where it is measured. The amount of infra‐red reaching the sensor
at the end of the tube is inversely proportional to the concentration of carbon dioxide because it
is absorbed by carbon dioxide.
PROBLEM STATEMENT
1) What gas will be released and consumed for photosynthesis?
2) What is the type of gas sensor that need to be used for this photosynthesis gas
experiment?
3) How to set up and connect the gas sensor to the computer correctly for this experiment?
4) What is the correct way/procedure to use the sensor in order to measure the amount of
gas that is released and consumed by a plant during photosynthesis more accurately.
5) What is the precaution step that need to be taken while using the sensor?
6) What is the correct and precise method to take the reading from the sensor?
7) How to calculate the rate of respiration/photosynthesis from the graph displayed on the
monitor?
8) How the application of the gas sensor help you to obtain result that is more accurate?
9) Can the use of the gas sensor help to reduce the difficulty of the experiment?
10) Is the use of the sensor burden students and make things complicated?

4. EMPOWERING
Objectives:
In this experiment, you will
1. Use an O2 Gas Sensor to measure the amount of oxygen gas consumed or produced by a
plant during respiration and photosynthesis.
2. Use a CO2 Gas Sensor to measure the amount of carbon dioxide consumed or produced
by a plant during respiration and photosynthesis.
3. Determine the rate of respiration and photosynthesis of a plant.

5. Materials:
1. LabPro or CBL 2 interface
2. TI Graphing Calculator
3. DataMate program
4. Vernier O2 Gas Sensor
5. Vernier CO2 Gas Sensor
6. CO2 – O2 Tee
7. 250 mL respiration chamber
8. Plant leaves
9. 500 mL tissue culture flask
10. Lamp
11. Aluminium foil
12. Forceps
Procedures:
1. Plug the O2 Gas Sensor into Channel 1 and the CO2 Gas Sensor into Channel 2 of the
LabPro or CBL 2 interface. Use the link cable to connect the TI Graphing Calculator to
the interface. Firmly press in the cable ends.
2. Turn on the calculator and start the DATAMATE program. Press CLEAR to reset the
program.
3. Set up the calculator and interface for an O2 Gas Sensor and CO2 Gas Sensor.
a) Select SETUP from the main screen.
b) If the calculator displays an O2 Gas Sensor in CH 1 and a CO2 Gas Sensor in
CH2, proceed directly to Step 4. If it does not, continue with this step to set up
your sensors manually.
c) Press ENTER to select CH 1.
d) Select OXYGEN GAS from the SELECT SENSOR menu.
e) Select parts per thousand (PPT) as the unit.
f) Press once, and then press ENTER to select CH2.

6. g) Select CO2 GAS from the SELECT SENSOR menu.
h) Select parts per thousand (PPT) as the unit.
4. Set up the data-collection mode.
a) To select MODE, press (the up arrow key) twice and press ENTER.
b) Select TIME GRAPH from the SELECT MODE menu.
c) Select CHANGE TIME SETTINGS from the TIME GRAPH SETTINGS menu.
d) Enter “15” as the time between samples in seconds.
e) Enter “40” as the number of samples (data will be collected for 10 minutes).
f) Select OK twice to return to the main screen.
5. Obtain several leaves from the resource table and blot them dry, if damp, between two
pieces of paper towel.
6. Place the leaves into the respiration chamber, using forceps if necessary. Wrap the
respiration chamber in aluminum foil so that no light reaches the leaves.
7. Insert the CO2–O2 Tee into the neck of the respiration chamber. Place the O2 Gas Sensor
into the CO2–O2 Tee as shown in Figure 1. Insert the sensor snugly into the Tee. The O2
Gas Sensor should remain vertical throughout the experiment. Place the CO2 Gas Sensor
into the Tee directly across from the respiration chamber as shown in Figure 1. Gently
twist the stopper on the shaft of the CO2 Gas Sensor into the chamber opening. Does not
twist the shaft of the CO2 Gas Sensor or you may damage it.
8. Wait two minutes, and then select START to begin data collection. Data will be collected
for 10 minutes.
9. When data collection has finished, remove the aluminum foil from around the respiration
chamber.
10. Fill the tissue culture flask with water and place it between the lamp and the respiration
chamber. The flask will act as a heat shield to protect the plant leaves.
11. Turn the lamp on. Place the lamp as close to the leaves as reasonable. Do not let the lamp
touch the tissue culture flask.
12. Press ENTER to view the graph of O2 GAS VS. TIME. Sketch a copy of your graph in
the Graph section below. When finished, press ENTER to return to the graph menu. Press
once, and then press ENTER to view the graph of CO2 GAS VS. TIME. Sketch a copy of

7. your graph in the Graph section below. When finished, press ENTER to return to the
graph menu. Select MAIN SCREEN from the graph menu.
13. Perform a linear regression to calculate the rate of respiration/photosynthesis.
a) Select ANALYZE from the main screen.
b) Select CURVE FIT from the ANALYZE OPTIONS menu.
c) Select LINEAR (CH 1 VS TIME) from the CURVE FIT menu.
d) The linear-regression statistics for these two lists are displayed for the equation in
the form: Y=A∗X+B
e) Enter the value of the slope, A, as the rate of respiration/photosynthesis in Table
1.
f) Press ENTER to view a graph of the data and the regression line.
g) Press ENTER to return to the ANALYZE menu.
h) Repeat Steps 13b – 13g to calculate the respiration/photosynthesis rate using the
data from the CO2 Gas Sensor (CH 2 VS TIME).
i) Select RETURN TO MAIN SCREEN from the ANALYZE menu.
14. Repeat Steps 8 – 13 to collect data with the plant exposed to light.
15. Remove the plant leaves from the respiration chamber, using forceps if necessary. Clean
and dry the respiration chamber.

8. Result:
O2 rate of CO2 rate of
Leaves production/consumption production/consumption
(ppt/s) (ppt/s)
In the dark -0.0023 0.00065
In the light 0.0045 -0.00126
Graphs:

9. Discussions:
1. Were either of the rate values for CO2 a positive number? If so, what is the biological
significance of this?
The CO2 rate value for leaves in the dark was a positive number. The biological
significance of this is that CO2 is produced during respiration. This causes the
concentration of CO2 to increase, as sugar is oxidized and broken into CO2, water
and energy.
2. Were either of the rate values for O2 a negative number? If so, what is the biological
significance of this?
The O2 rate value for leaves in the dark was a negative number. The biological
significance of this is that O2 is consumed during cellular respiration. This causes
the concentration of O2 to decrease as glucose is oxidized for energy.
3. Do you have evidence that cellular respiration occurred in leaves? Explain.
Yes, cellular respiration occurred in leaves since O2 decreased when leaves were in
the dark and photosynthesis was not possible.
4. Do you have evidence that photosynthesis occurred in leaves? Explain.
Yes, photosynthesis occurred in leaves since O2 increased when leaves were exposed
to the light.
5. List five factors that might influence the rate of oxygen production or consumption in
leaves. Explain how you think each will affect the rate?
a) A greater number of leaves should increase the rate since there are more
chloroplasts to undergo photosynthesis and more cells to require energy
through cellular respiration.
b) A greater light intensity will increase the rate of photosynthesis. It may not
affect the rate of cellular respiration.
c) A cooler room may decrease both rates, as cellular metabolism decreases in
cooler weather.

10. d) Facing the top of the leaves toward the light should increase the rate of
photosynthesis, since the chloroplasts are closer to the light source.
e) If the plants overheat due to the heat from the lamp, they may wilt and stop
functioning. This will decrease all rates.
f) If there too many leaves, diffusion may be restricted and prevent accurate
readings. This may apparently decrease both rates.

11. ENHANCING
Oxygen is a chemical element with symbol O and atomic number 8. At standard
temperature and pressure, two atoms of the element bind to form dioxygen, a colourless,
odourless, tasteless diatomic gas with the formula O2. This substance is an important part of the
atmosphere, and is necessary to sustain most terrestrial life. Without oxygen gas, human and
animals cannot life in this planet. Besides, the oxygen gas also is important in producing some
other material from combining with other element or material, for industrial, for combustion,
medical, for research, for astronaut at outer space, diving and many else. The uses of the oxygen
gas is divided into two group, first is directly use such to produce the new substance that
combine with the oxygen gas and use in daily life to breath and second indirectly use such we
store the oxygen gas and use it when we need it for other purpose.
Firstly are the direct uses, human, animals and other organism need oxygen gas for the
respiration process to life. Without oxygen gas, human, animals and other microorganism also
will die. Other, the oxygen is needed to combine with another elements to be other compound
such water, (H2O) the combination of two molecule Hydrogen and 1 molecule of oxygen. The
combustion also needs an oxygen gas to occur. The example of the combustion equation is CH4
+2O2 = CO2 +2H2O. Without Oxygen gas, the combustion process will not happen. The
application of this combustion is such in the engine, the combustion in engine will move the
piston and make the machine such car, bus, ship, aeroplane and other machine to move.
Secondly are the indirect uses. These mean that the Oxygen gas was stored at some
cylindrical bottle or on a tank for other purpose. The application of the oxygen gas that stored in
the cylindrical bottle or in tank is used for diving, welding, cutting of metal, used at the outer
space, in aircraft, in medical, and many else. The highly technology was used such the gas
compressors, oxygen sensor, the oxygen concentrator, the compressors oxygen cylinder and
many else was used to store the oxygen gas. This cylindrical oxygen gas is used only when it
needed. In diving activities, the divers will use the oxygen gas cylinder to support them with
oxygen when inside the deep sea.

12. For welding, the oxygen gas was needed to support and give an enough amount of
oxygen gas to do the combustion process in high temperature to melt the metal used. At the outer
space, there is vacuum and have no oxygen gas, therefore there need to take the oxygen gas from
Earth to the outer space by store it in the oxygen tank, the oxygen sensor also is very important
in the outer space to detect the oxygen concentration there to help the astronauts to prevent the
lacking of the oxygen gas. Other, in the aircraft, the oxygen gas tank and the oxygen sensor is
important in emergency and to detect the concentration of oxygen gas inside the aircraft. When
the aircraft is fly too high, the concentration of nitrogen gas is higher the oxygen gas, therefore it
will caused the passengers difficult to breath, so the pilot need to supply them with the oxygen
gas to help them to breathe through the funnel oxygen gas.
Besides that, the major uses of the cylinder bottle or tank oxygen gas in medical
application. When the people are sick, their ability to breath is limited, therefore we need to help
them to supply the oxygen gas to them by using the specific mask. Oxygen masks are
administered medically for patients in the hospital or at an outside emergency scene, where EMT
personnel are summoned, or in the emergency room. Oxygen masks are also used in oxygen
therapy. They are used for those suffering from pulmonary conditions or disease. The other form
of oxygen element in medical is liquid oxygen which is stored in cryogenic (cold) storage
containers. Liquid oxygen is used to produce vitamin supplements. Oxygen travels with the
supplement to the digestive tract to detoxify the body. Sometimes liquid oxygen comes in the
form of a spray. This form helps heal minor cuts, wounds or abrasions.
Therefore, the Oxygen gas is very important in our daily life not just for breathe, but can
be used to make our work easily. Besides, the oxygen gas also important in producing some
other material from combining with the other element or material, for industrial, for combustion,
medical, for research, for astronaut at outer space, diving and many else. The uses of the oxygen
gas is divided into two group, first is directly use such to produce the new substance that
combine with the oxygen gas and use in daily life to breath and second indirectly use such we
store the oxygen gas and use it when we need it for other purpose.

13. Picture 1: Mini Oxygen gas cylinder for medic Picture 2: Common oxygen gas cylinder
Picture 3: Oxygen gas cylinder for diving Picture 4: Oxygen gas tank for astronaut

14. Picture 5: Oxygen gas cylinder for welding Picture 6: The Oxygen tunnel inside the aircraft

15. REFERENCES
Internet:
1. Types of Oxygen Cylinders. Retrieved December 2nd, 2012, from
http://www.ehow.com/list_5954302_types-oxygen-cylinders.html#ixzz2DsX6Y4YI
2. Oxygen Vs. Medical Oxygen. Retrieved December 2nd, 2012, from
http://www.ehow.com/about_5627973_oxygen-vs_-medical-
oxygen.html#ixzz2DsWaWxbP
3. Photosynthesis and Respiration. Retrieved December 2nd, from
http://education.ti.com/xchange/US/Science/Biology/3797/Vernier
Act25_photosynthesis.pdf
Book:
1. Starr Cecei, Chiristine A. E and Starr Lisa (2011). Biology Concept and Application(8th
Ed).USA: BROOKS/COLE Gangage Learning.
2. Brown, T. L. LeMay, H. E. , Bursten, B. E. , and Murphy, C. J. (2009). ChemistryThe
Central Science. (11th ed.). London: Prentice Hall.