In the Classroom edited by
NSF Highlights
Susan H. Hixson
Projects Supported by the NSF Division of Undergraduate Education
MeasureNet—Electronic Measurement Network for the Freshman Chemistry Laboratory
National Science Foundation Arlington, VA 2230
Curtis T. Sears, Jr. Georgia State University Atlanta, GA 30303
Estel D. Sprague,* Robert Voorhees, Paul McKenzie, John J. Alexander, and Peter Padolik Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221-0172
MeasureNet is a data collection and analysis network designed to provide high-quality electronic measurements in science laboratories. It departs significantly from the usual approach by not using a personal computer at each laboratory work station. This frees up valuable bench space and substantially reduces the quantity of equipment to be maintained. The networked nature of the system leads to easier implementation of both cooperative and discovery types of exercises by facilitating the combining and sharing of data among groups of students. A MeasureNet system consists of 10 measurement and display stations, 1 network controller, and 1 PC with printer, and it serves 20 students working in pairs. Our laboratories have space for 200 students, so we have installed 10 complete networks. One teaching assistant supervises the 20 students on each system. Through menus on the station display, the students select the measurement type (pH, temperature, pressure, voltage, etc.), calibrate the probe(s), and begin collecting data (Fig. 1). The controller monitors all activity, allowing independent work at each station. As the experiment proceeds, the data are displayed and plotted on the 240 × 64 pixel graphic LCD display at the station. When an experiment calls for more sophisticated data manipulation or the production of hard copy, the students download their data to the PC, manipulate it there, and print tables or high-resolution graphs on the attached laser printer. All steps at the stations and the PC are menu driven and easy for the students to follow independently with little training. It is also easy to save data sets for further analysis at a later time. The latest addition to the MeasureNet system is a miniature diode array spectrometer, built around a commercially available miniature monochromator. We will finalize the design of our working prototype very soon and connect a spectrometer directly into each of our networks. Visible emission or absorption spectra, with an optical resolution of 3 nm, can be measured and then displayed on any station on the network, which is effectively functioning as a spectrometer with up to ten separate data stations. Actually measuring a spectrum requires only a few seconds. After recording their individual spectra, the students can work with the results at their leisure. The data can be downloaded and printed at high resolution, yielding high-quality spectral results. *Corresponding author.
[email protected] Figure 1. MeasureNet measurement and display station.
MeasureNet is catalyzing ongoing change in our program. We are introducing some multi-week projects, in which small teams of students share complementary data and arrive at group conclusions. In other cases, all 20 students on a MeasureNet system cooperate by dividing up the experimental work. As a simple example, the group determines freezing points for a variety of solutions, varying the solvent, the solute, and the concentration. The combined results are discussed in the latter portion of the laboratory period, while still fresh, and the students are encouraged to discover patterns of behavior for themselves. This provides a qualitatively different experience and atmosphere in the laboratory than we have had in the past. The students develop a better grasp of the systems under study, as well as of the manner in which scientists gather data and arrive at scientific laws. MeasureNet was developed initially for the freshman laboratory, but its high-quality measurement capabilities make it suitable for use at any level. We will be introducing it into our physical and analytical laboratories in the future. It will be interesting to see where MeasureNet takes us as we continue to revise and upgrade our laboratory curriculum. Acknowledgments This work was supported equally by a grant from the National Science Foundation Division of Undergraduate Education Instrumentation and Laboratory Improvement program (DUE 9650017) and a Curriculum Development Grant from the Procter & Gamble Fund.
JChemEd.chem.wisc.edu • Vol. 75 No. 7 July 1998 • Journal of Chemical Education
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