A Simple Device for Measuring Chart-Recorded Spectra In many undergraduate and research laboratories it is necessary to measure the positions or separations of peaks on strip-chart records. We have found the following device to be very useful for such purposes. A calibrated steel straightedge is fmtened to a drawing board. The chart is fastened to the drawing board with drafting tape with its edge against the stmightedge. The positions of the chart features and any calibration marks on the chart are projected onto the calibrated straightedge using 8. 12-in. transparent draftsman's triangle and recorded m scale position. The actual values of peak positions are then cdculated by numerical interpolation between ealibrat,ionpoints. To improve the precisian of measurement a line is scribed on the under side of the triangle at right angles to the base and a. vernier is attached to the base of the triangle. Using a scale graduated in 0.1-in. units and a 10: 1vernier the positions of sharp peaks can emily be measured to the nearest 0.01 in. Using 8. metric scale the readability is to the nearest 0.2 mm. OX. MANITORA UNIVERSITY WINNIPEG, CANADA R3T 2N2
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Journal o f Chemical Education
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