Data Acquisition and Analysis with LabVIEW
Student: Nathan McReynolds
Faculty Mentor: Professor Walhout
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The overall goal of our project was to trap Krypton and Argon atoms and be able
to gather data from the trap. A laser set to the natural frequency of the atoms is able to
trap these particles. By adjusting the parameters of the trap we can study captured
atoms. My part in this project was to learn how to use a computing language called
LabVIEW in order to create programs that can perform data acquisition and analysis.
LabVIEW is a graphical programming language that uses Virtual Instruments (VIs),
which act as methods and classes, to create programs. Unlike most computing
languages, LabVIEW uses diagrams and wires to represent the code that is being
written in order to demonstrate the flow of the program’s execution. The data flow
oriented programming of LabVIEW is designed specifically for acquiring data from
physical systems.
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In our project, the physical system was the atom trap. One experiment that can
be done on this system involves finding the temperature of the particles in the trap by
measuring the rate of decay of the intensity of light emitted by the atoms as they are
caught and released. In order for LabVIEW to perform this experiment it needs to be
able to acquire images from a camera and then analyze these images for changes in
light intensity. LabVIEW has a variety of VIs specifically for grabbing photographs and
analyzing their properties. It was also important in our project to be able to read and
write voltage signals. VIs such as “DAQ assist” are specifically designed to find devices
connected to the computer and either read or write any signal given to them.
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Using these VIs, I have put together four major programs. The first one grabs
images from any USB camera connected to the computer and saves them to a file the
user specifies. The second program retrieves these images and then averages the light
intensity over a specified area. This light intensity is then fitted and displayed as a
Gaussian function over the area of interest and as an exponential function over each
image number. All the data from this second program is saved to a text file that can later
be opened in Excel. The third and fourth programs function similarly to each other. Both
are able to control digital and analog outputs and fit data that it reads in. However, one
program can control a delay between the signals it writes while the other can output
signals synchronized to within a microsecond.
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This research project benefited me personally by allowing me to see how
computing and scientific research can be combined. Since this a career interest of mine
that I plan to pursue after college, I have gained much from this experience. I am now
proficient in a new computing language that is used by industries worldwide. With
LabVIEW I am able to create a program for almost any system that needs to be
analyzed. In addition to the programming side of the experiment I learned basic metal
shop and circuitry skills by assisting in other parts of the project. I am now able to set up
bread board circuits and solder the final results. I can now work the machines in the
metal shop with competency after going through lessons in the shop. Over all, the
greatest benefit has come from the real world applicable skills of this research
project.!
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