Vernier Graphical Analysis 3 - Manual (Page 20)

Graphical Analysis for Windows TEACHER’S MANUAL
22
Importing Text
You can import data saved with the Export Text menu item or files created and saved from other software (e.g. Excel).
The file must be in the tab-delimited or comma-separated text format (a .txt, .TEXT, .dat or .csv extension). Data are
imported only into the latest data columns. You can also use this feature to import data prepared or collected in another
program into Graphical Analysis. Several different formats are supported and are automatically detected.
Supported formats are:
• Data exported as text from Logger Pro (or from Graphical Analysis 3.0)
• Graphical Analysis for Windows 2.1 files saved as “.dat”(not exported as text)
• Data exported as text from Graphical Analysis 2 for Macintosh
• Generic tab or comma-separated data. Data can be strings or numbers
Note: If a word processing program is used to prepare data in any of these formats the file must be saved as text.
Each text file created in Graphical Analysis file has a specific structure that includes a time stamp, data column names,
short names, units, and data. If you make changes to the exported file, be sure to preserve the structure. After choosing
this option, select the appropriate file name in the Open File dialog.
Sample Data Files
A variety of sample data is included with the Graphical Analysis 3 software. This data can be found in the Sample Data
folder of Graphical Analysis. The Sample Data folder contains five folders – Biology, Chemistry, Physics, Imported
Data, and from older versions of Graphical Analysis. Here are the contents of each folder.
Biology
Cell Respiration
Cell respiration is the process of converting the chemical energy of organic molecules into a form immediately
usable by organisms. These data show the CO
2
gas levels during the respiration of germinating peas. Notice that a
linear fit has already been done to show the rate at which CO
2
was produced.
Diffusion
This data compares the increased conductivity that results when various concentrations of saline solution diffuse
through dialysis membranes into dissolved water. A linear fit to the data in a particular run represents the rate at
which the salt is diffusing.
EKG
The EKG is a graphic tracing of the heart’s electrical activity. A typical tracing consists of a series of waveforms
occurring in a repetitive order. A little more than one waveform is displayed in this sample file.
Fermentation
When yeast ferments sugars anaerobically, CO
2
gas is produced. The data shown represent the change in pressure as
the gas is produced. A linear fit to the data determines the rate at which fermentation occurs.
Transpiration
Transpiration is the loss of water from the leaves of a plant. The rate of evaporation of water from the air spaces of
the leaf to the outside air depends on the water potential gradient between the leaf and the outside air. The data
shown here represent the pressure change in an airtight tube filled with water into which a cut leaf is inserted. As the
leaf takes up water into the stem (replacing that lost from transpiration) the pressure in the tube decreases. A linear
fit to the data determines the rate of transpiration. In this experiment, a fan was used to blow air across the leaf as
the pressure was measured.