Introduction to Data Collection. Evaluation copy

Transcription

1 Introduction to Data Collection Computer 1 Data collection is a very important part of science. Meteorologists collect weather data over time to keep an historical record and to help make forecasts. Oceanographers collect data on the salinity (saltiness) of seawater to study changing trends in our Earth s oceans. While data have been collected by hand for thousands of years, the technology to collect data electronically has been around for fewer than 80 years. Only in the last 20 years has this technology been available to schools. This experiment was designed to introduce you to two of the most common modes of data collection that will be used in this class. Part I will guide you through collecting and analyzing data over time. A Temperature Probe will be used to record the temperature of water for 60 seconds at a rate of one sample per second. In Part II, you will collect data using a mode called Events with Entry. This style of data collection allows you to collect one point of data, then will ask you to type in a corresponding value. In this experiment, the data collected will be the temperature of your hand and the value you type in will be your assigned group number. OBJECTIVES In this experiment, you will Become familiar with the Logger Pro computer program. Use a computer and a Temperature Probe to make measurements. Analyze a graph of the data. Use this graph to make conclusions about the experiment. Determine the response time of a Temperature Probe. MATERIALS computer Vernier computer interface Logger Pro Vernier Temperature Probe two 250 ml beakers cold tap water hot tap water ice Evaluation copy Figure 1 Agricultural Science with Vernier 1-1

2 Computer 1 PROCEDURE 1. Place about 100 ml of tap water into a 250 ml beaker. Add two or three ice cubes. 2. Connect the Temperature Probe to your Vernier computer interface. 3. Place the Temperature Probe into the cold water and stir briefly. Then position the probe in the cold-water beaker as shown in Figure 1. Note: Make sure the beaker will not tip over from the weight of the Temperature Probe. 4. Prepare the computer for data collection. a. Choose Open from the File menu. b. Open the Agricultural Science with Vernier folder. c. Open the file 01a Intro to Data. 5. Place about 150 ml of hot water into a second 250 ml beaker. 6. Click to begin data collection. Do not stir or move the water. 7. When exactly 10 seconds have gone by, quickly move the Temperature Probe to the beaker containing hot water and allow the computer to continue data collection. Do not stir the water or move the Temperature Probe during the remainder of the data collection period. 8. Data collection will stop automatically after 60 seconds. 9. Remove the Temperature Probe from the beaker and dry it with a paper towel. 10. Determine the time at which the highest temperature was reached. There are several ways to accomplish this. Try them all. a. Move the cursor to the point on the graph where it appears the highest temperature was reached. b. As you move the cursor across the graph, notice that there is a live readout of the x- and y-coordinates at the bottom of the screen. This readout of the cursor location is a fast and easy way to interpret a graph. c. Click the Examine button,, on the toolbar. The cursor now includes a vertical line. As you move the cursor across the graph, it will jump from one data point to the next. The temperature and time values corresponding to its position will be displayed in the Examine Box. d. Use the left and right arrow keys to scroll across the highest portion of the curve. Which do you prefer, the mouse or the left and right arrows? e. Find the highest temperature. Record this temperature and the time when it was first reached in your data table. f. Close the Examine Box by clicking the upper-left corner of the box. g. To confirm the time when the highest temperature was first reached, use the scroll bars in the table to scroll through the table and examine the data. 1-2 Agricultural Science with Vernier

3 Introduction to Data Collection 11. Practice changing the graph scaling. In future experiments, you may want to change the scale of either axis of a graph. There are several ways to do this. a. To scale the temperature axis from 0 to 80 C instead of the present scaling, click the mouse on the 100 tickmark at the top of the axis. In the edit box that appears, type in 80 and press the ENTER key. Notice that the entire axis readjusts to the change you made. To scale the time axis from 0 to 150 seconds instead of the present scaling, click the mouse on the 60 tickmark at the right end of the axis. In the edit box that appears, type in 100 and press the ENTER key. b. Another way to change scaling is to click the Autoscale button,, on the toolbar. The computer will automatically rescale the axes for you. Try it. 12. Print copies of the graph as directed by your teacher. 13. Prepare the computer for data collection. a. Choose Open from the File menu. b. Open the Earth Science with Vernier folder. c. Open the file 01b Intro to Data file. 14. Number the members of your group by age with the oldest being number one. Record the names in your data table. Add more lines if needed. 15. Click to begin data collection. Figure Measure the hand temperatures of your group members. a. Group member number one should pick up the Temperature Probe and hold its tip in the palm of his/her hand as shown in Figure 2. b. Watch the live temperature readout in the Meter window. When the temperature has stopped rising, click. c. You will be prompted to type in a number. Type in 1 for your group member number and press the ENTER key. The temperature and group member number have been saved in the data table. 17. Cool the Temperature Probe back down by placing it in the cold water from Part I. Monitor the temperature in the meter and remove it from the water when the temperature reaches 25 C. 18. Pass the Temperature Probe to the next group member. 19. Repeat Steps until every group member has their hand temperature recorded. 20. Click to end data collection. 21. Determine each person s hand temperature by using one of the methods described in Step 10. Record them in the data table. 22. Print copies of the graph as directed by your teacher. Agricultural Science with Vernier 1-3

4 Computer 1 DATA Maximum temperature ( C) Elapsed time (s) Group member number Group average Group member name Maximum temperature ( C) PROCESSING THE DATA 1. Describe the appearance of your graph in Part I. 2. Why is time plotted on the horizontal axis in this experiment? 3. Why is temperature plotted on the vertical axis? 4. Determine the Temperature Probe s response time. To do this, use your data to find how long it took for the Temperature Probe to reach the maximum temperature after moving it from the cold water to the hot water. 5. Explain how you determined your answer to Question Calculate your group s average for the maximum temperatures. Record the result in the data table. 7. Who had the hottest hand? 8. Who had the coldest hand? 1-4 Agricultural Science with Vernier

5 Vernier Lab Safety Instructions Disclaimer THIS IS AN EVALUATION COPY OF THE VERNIER STUDENT LAB. This copy does not include: Safety information Essential instructor background information Directions for preparing solutions Important tips for successfully doing these labs The complete Agricultural Science with Vernier lab manual includes 29 labs and essential teacher information. The full lab book is available for purchase at: Vernier Software & Technology S.W. Millikan Way Beaverton, OR Toll Free (888) (503) FAX (503)