Activity 1: TI Temps - Using the TI Temperature Probe As a Thermometer

TI-73 Explorer Activity Cards

Activity 1: TI Temps - Using the TI Temperature Probe as a Thermometer

In this investigation you will set up the calculator with the temperature probe and the CBL2 to collect temperatures.

1. Turn on the TI-73 Explorer and press the  key to get the APPLICATIONS menu. Use the down arrow  to help find and highlight the CBL/CBR APP. When you have the APP highlighted press  to run it. Press any key to get past the splash screen that tells which version of the APP you have on the calculator. [Periodically check with TI Connect or the TI web page for newer versions of APPS.] From the CBL/CBR APP menu select 1:GAUGE. Either press or  to run the GAUGE program.

2. Set up the GAUGE program to do the experiment with the temperature probe. Do this by moving to each line with the directional arrows [], highlighting the choice for each item and pressing  to select it. In this investigation we want the following:
PROBE: Temp
TYPE: Bar
MIN: 0
MAX: 40
UNITS: °C
DIRECTNS: Off
We set the GAUGE this way since we want to collect temperatures that range from 0 to 40 degrees Celsius displaying the values on a Bar to simulate a thermometer. We leave the directions off, but some will want them on the first time they set up the investigation.

3. Now connect the calculator to the CBL2 and place the temperature probe into CH 1 on the left side of the CBL2. Make sure the I/O cable is pushed in snugly into both the bottom of the calculator and the CBL2 with no metal showing. When you are ready highlight the GO… option and press . If you get a link error check the I/O cable, look at the connections and make sure the CBL2 has batteries or power.

4. You will now see the temperature of the tip of the probe shown on a bar. The default is to show the temperature to the hundredths place. You can control this by adjusting the MODE on the calculator before you start the CBL/CBR APP. Move the probe to different locations and collect the temperatures. Make sure you give the temperature probe enough time to adjust to the new surroundings.

Item / Temperature (°C)
Milk
Hand
…

5. Collect seven temperatures of things in the room. Place them in a table as shown below:

6. To stop the data collection press  to stop the GAUGE program, and then press  to return to the CBL/CBR APP menu. Press  to select 4:QUIT to quit the APP and return to the Home Screen. Press  a few times to remove any debris left from earlier interactions and leave you with a clean screen.

7. When you have all seven items measured and recorded, consider the nature of the items measured (solid, liquid, or gas); the room temperature (which items were hotter, which cooler); and the mean, median, mode, and range of your values.

Activity 2: Warming UP – How Fast Do things Warm?

In this investigation you will set up the calculator, the temperature probe and the CBL2 to study rates of heating.

1. Connect the calculator to the CBL2 and place the temperature probe into CH 1 on the left side of the CBL2. Make sure the I/O cable is pushed in snugly into both the bottom of the calculator and the CBL2 with no metal showing. When you are ready turn on the TI-73 Explorer and press the  key to get the APPLICATIONS menu. Use the down arrow  to help find and highlight the DATAMATE APP. When you have the APP highlighted press  to run it. Notice the splash screen that tells which version of the APP you have on the calculator and the OS of the CBL2. [Periodically check with TI Connect or the TI web page for newer versions of APPS and device OS.] If you get a message that the Data Collection is done, just press to pass that screen. If you had an experiment from before, follow the instructions to explore the results.

2. Now the program should recognize your probe and set it up to collect data over time (180 seconds). It also should report the temperature of the tip of the probe in degrees Celsius. If this is not the case, press  to reset the program.

3. We want to explore the rate that the probe will heat up, so we need to get it cold. Place the probe in a mixture of water and ice. Make sure you secure the set up so that the container of ice water does not get knocked over. It is best to assign a team member to this job (hold the probe and the container and keep the probe in the ice water). Let this sit for a bit until the probe reads the temperature of the mixture (maybe as low as 4°C).

Time (sec) / 0 / 15 / 30 / 45 / 60 / 75 / 90 / 105 / …
Temperature (°C).

4. We want to collect the temperature every 15 seconds as we move the probe from the ice water to the air. Start the investigation as the clock in the room has its second hand at :00, :15, :30, or :45. The first reading will be the temperature of the ice at time zero. Move the temperature probe into the air and hold it steady out of any air flow at the instant you start the time readings. As the temperature changes the current value will be reported on the screen. Have one student watch the time, one holding the probe and one watching the calculator screen. As the second hand hits the 15 second mark have the clock watcher tell the calculator watcher to read the temperature. Have another student record the temperatures in a table, as shown below.

5. Now we would like to repeat the experiment letting the calculator collect the temperatures over time. To do this, place the temperature probe back into the ice water mix and let it come to be one with the mixture. When ready simultaneously press the number on the calculator (to pick 2:START) and move the temperature probe from the ice water to the air. Notice the lights and sounds of the CBL2. Hold the temperature probe steady and out of any air flow as before until the time runs out. Notice the current temperature is reported periodically on the graph.

6. Make a sketch of the graph when the experiment is over and then press  to return to the main screen. Press  to select 6:QUIT and leave the DATAMATE APP. Note that the times for the experiment are stored in L1 and the temperatures are in L2. These are lists on the TI-73 Explorer. Press as instructed and  a few times to get a clean Home Screen.

7. Determine the rate of change of the temperature using the data you recorded manually. From the home screen subtract the temperature at 0 seconds from the temperature at 30 seconds. Divide this number by the time difference (30 – 0). This ratio is the time rate of change of the temperature. Its units are °C per second. It is also called the slope. Using the formula below [Note that if you do all the calculations at once that you should use parenthesis to enclose the numerator and denominator like this: (15.1 - 7.2)/(90 - 45) ] determine when the greatest rate of change occurred? When was the smallest rate of change? Can you see those on the sketch above? To see the graph again, press  and  for 7:ZoomStat. This resets the WINDOW and puts you on the graph screen.

8. Press  and use the right  and then left  arrows to move along the plot. Check one of your calculations from number 7, using the data from the second run of the experiment. How are these rates the same? Different? Why?

9. You may also see the raw data from the second run of the experiment by pressing  and then scrolling up and down the lists. Look at these values and compare them to what you recorded manually. Did you have the same temperatures at the same times? Explain.

Activity 3: Ray-Bans or Ban Rays? – Using the Light Probe

In this investigation you will set up the calculator, the light probe and the CBL2 to compare different sunglasses for their ability to block out light.

2. Set up the GAUGE program to do the experiment with the light probe. Do this by moving to each line with the directional arrows [], highlighting the choice for each item and pressing  to select it. In this investigation we want the following:
PROBE: Light
TYPE: Meter
MIN: 0
MAX: 1
UNITS: mW/cm2
DIRECTNS: Off
We set the GAUGE this way since we want to collect light intensities that range from 0 to 1 milliwatts per square centimeter displaying the values on a Meter to simulate a light meter. We leave the directions off, but some will want them on the first time they set up the investigation.

3. Collect about 7 different pairs of sunglasses for this experiment. We also will need a DC light source. A flashlight will do, but we need to set it up so that the position and direction of the light won’t change over the different trials. When you have all of the equipment at hand, highlight the GO…. Option and press  to start the data collection.

Glasses / Code / Light Level
Green Ray-Bans / 1
SAM’s House of Dark / 2
The Red Glass / 3

4. For the experiment position the end of the light probe so that it points at the light source. Move it toward or away from the light until you get a reading of around 0.8. Secure the light probe so that it won’t move or change direction over the different trials. Place the center of one of the lenses of the first pair of sunglasses over the end of the light probe. Hold things steady until the level stabilizes and then press  to record a Comment. We will just code the glasses with numbers [1, 2, 3…] so quickly (right after you press , press  for the 1st pair of glasses). Record this reading in a table like the one below and continue on. If you take too long to enter the comment you may lock up and have to start over. Repeat this process for each pair of sunglasses.

5. When you have collected all the data (with no more than 7 pairs of glasses), press  to stop the GAUGE program, and then press  to return to the CBL/CBR APP menu. Press  to select 4:QUIT to quit the APP and return to the Home Screen. Press  a few times to remove any debris left from earlier interactions and leave you with a clean screen.

6. Now to help determine which pair of glasses does the best job, we will set up a plot. Press  to get the STAT PLOTS screen. Select Plot 1 with your cursor and press .

7. Press  to highlight On. This turns the plot on.

8. Press to move to the bar graph and press  to select it.

9. For CategList, choose the LCMNT list. Press and use the arrow to move down to LCMNT and press  to select it. Do the same for Datalist1 but this time select the list named LIGHT. Select Hor to get horizontal bars and 1 since we have just data set of light intensities.

10. Press  to get the graph and then . To move over the different pairs of glasses use the  and  keys. Which pairs is best and how much better is it?

Activity 4: Light Bulbs? – Is a 40 Watt Light Bulb Half as Dim as an 80 Watt?

In this investigation you will set up the calculator, the light probe and the CBL2 to compare different light bulbs.

1. To do this experiment we will need a light fixture and several different levels of light bulbs [40 W, 60 W, 75 W, 100W, etc.]. We also need a way to support the light probe so that it keeps its orientation and distance toward the light bulb as we try different bulbs.

2. Connect the calculator to the CBL2 and place the light probe into CH 1 on the left side of the CBL2. Make sure the I/O cable is pushed in snugly into both the bottom of the calculator and the CBL2 with no metal showing. When you are ready turn on the TI-73 Explorer and press the  key to get the APPLICATIONS menu. Use the down arrow  to help find and highlight the DATAMATE APP. When you have the APP highlighted press  to run it. Notice the splash screen that tells which version of the APP you have on the calculator and the OS of the CBL2. [Periodically check with TI Connect or the TI web page for newer versions of APPS and device OS.] If you get a message that the Data Collection is done, just press to pass that screen. If you had an experiment from before, follow the instructions to explore the results.

3. Now the program should recognize your probe and set it up to collect data over time (9 seconds). It also should report the light intensity for the probe in milliwatts per square centimeter. If this is not the case, press  to reset the program.

4. We want to determine the relative light intensity for several light bulbs and see if they compare as a percent of each other. For example a 75 Watt light bulb should be 50% as bright as a 150 Watt bulb. To set up the positions for the light bulb and the light probe, place the highest wattage bulb in the fixture and move the light probe, with the end of the probe pointing at the center of the bulb until this reading is about 0.9. Lock the probe in position so that it won’t move until the experiment is over. You can observe the light reading from the Main Screen in DATAMATE.