Kazuomi Itoh, Dayu Ding and Tadao Yoshida*
Abstract: Spectra and color values of the light from LEDs and liquid colors were measured using the PMA-11C7473-36 spectrometer as a preliminary study of the color of fireworkflames. The light from LEDs was stable and reproducibly measured. The color values of the light from LEDs did not vary with change in the exposure time of the spectrometer and the distance between the light and the incident point. The color values of the flames of liquid colors were less stable than those from LEDs owing to the flickering of the flame, but nearly constant with the change of exposure time and distance. The peak heights of the flame spectra of the liquid colors were proportional to the exposure time, but when the highest peak was saturated the proportionality changed. The red and yellow spectra of the liquid colors consisted of the single peaks from Li and Na atoms, respectively, with high excitation purity. The green and blue spectra consisted mainly of the molecular spectra of BO2 and CuCl, respectively, with moderate excitation purity. The concentrations of the principal color emitters of the flames of alcohol colors were calculated using a computer program for chemical thermodynamics.
Keywords: flame spectra, liquid colors, LED, spectroscopic measurement, thermodynamic modeling
Ref: JPyro, Issue 24, 2006, pp17-27
(J24_17)
© Journal of Pyrotechnics and CarnDu Ltd
