EXPERIMENT

"CANDLE IN A BOX"

INTERACTIVE LAB EXERCISE

EXPERIMENT

Experimental Objectives:

A) To locate a heat source in a cardboard box using collection of temperature data
throughout the box and analysis of data
B) To experiment with volume visualization of temperature data from probes in a
cardboard box under various temperature conditions

Materials:

cardboard box (size: 24" x 18" x 18")

8 digital temperature probes (Vernier Direct-Connect Temperature Probes)

A to D converters with power supplies and cables to connect to computers

computers and software (Data Logger and Noesys) to process and display data

awl or punch tool to put holes in cardboard box (for probe passage)

heat source (desk lamp with 60 watt light bulb) (do not use Tungsten bulbs - or candles - in spite of the title!)

for cold source: ice, ice packs, or dry ice, and insulated gloves to handle dry ice and heavy Pyrex glass dish(es) to contain dry ice

black marker pens

"grease" pens or "crayon" pens for marking glassware

white (& other color) label tape

rulers

tape (mailing tape or duct tape)

weights for bottom of box to prevent tipping

Protocol:

Set Up Experiment and Collect Data

1) Position the cardboard box so that it will open at the top.
2) Record the dimensions of the cardboard box.

3) Punch holes in the box for placement of the probes. (see #6 below)

4) Record the positions/locations of the holes in the box.

5) Connect 2 probes to each of 4 A to D converters, each attached to a computer.
See Fig. a.

Fig. a. Cardboard box tilted on one side for photograph to show probes and lamp inside box with 2 probe connections to one A to D converter and to computer outside box. During experiment, box is oriented with flaps opening toward ceiling and with lamp base on bottom of box.

6) Insert probe tips into holes in the box far enough so there is a 12-inch distance between
the tips of each probe and its nearest neighbor. This way the probe tips form a 1-foot
cube. See Fig. b.

Fig. b. Cardboard box in experimental orientation showing probe positions with probe tips 12 inches apart (12" ruler on bottom of box).

7) Open the top of the box, if it is not already open.

8) Place your heat source, the lamp, into the box and record its location. At this point
    briefly test the lamp to make certain that it works. Be able to turn the lamp on and off
    outside of the box by a switch or by plugging and unplugging the lamp. Make sure the
    lamp is switched on but unplugged before closing the box lid. Loosely tape the lid shut
    and allow the air temperature inside the box to equilibrate (estimated to take 5 minutes).

9) Power on the computers and the A to D converters. Open the Data Logger software.
    Follow separate instructions in Appendix A for using Data Logger software and
    recording temp probe data. (note: You will set your computer to record temperatures
    for a 20-minute period.)

10) Start your computer-driven recording of the temperatures. Your starting point is 0
    minutes. Your computer software (Data Logger) should be recording the
     temperature readings. The temperature readings between 0 minutes and the time that
     the heat source is turned on (1 minute here) are the "baseline" temperatures.

11) At exactly 1 minute (Minute 1), the lamp should be plugged in (which turns on
      the heat source inside the box).

12) The computers will continue recording the temperature for each probe at 2 minutes,
    3 minutes, 4 minutes, 5 minutes, and 6 minutes. The data recorded at the times:
     Minute 2, Minute 3, Minute 4, Minute 5, and Minute 6 are the "experiment"
    temperaturereadings. In regard to the computer-driven recordings, the frequency
     of data collection (temperature values over time) and the duration of data collection
     (how long data values are collected) are options that you set using the computer
     software itself.

13) After exactly 5 minutes of heat (Minute 6), the lamp should be unplugged (which
      turns off the heat source inside the box).

14) Continue recording the temperatures for 15 additional minutes (Minutes 6
      through 20). The computer should stop at 20 minutes if programmed correctly.
     (Note: You can preset the amount of time the experiment will be recorded by Data
      Logger software. We ran the experiment for a total of 28 minutes, that is, for 22
      minutes after the heat source had been turned off to collect the dataset we use here.)

15) Stop the computer recording of temperatures at the end of 20 minutes by clicking the
    Stop button at the lower left corner of the screen if the computer does not stop
     recording automatically.

Remember to save your computer-recorded temperature data file. You will have to use it later.

This Protocol continues in the Data Processing sections and the Data Analyzing sections (See
"Next" button below for link to the Data Processing I section. The other sections are linked in a series from that section. If you wish to choose from a visual listing of all the lab sections, go to
the "Flow Chart.")

Last Update: 13 May, 1999