Lamp emission spectra Lamp emission spectra[ INTRODUCTION | PHOTON SPECTRA | ENERGY SPECTRA | OTHER SPECTRA || Index | About ]
I used to have the plots of lamp emission spectra as GIF images. I have re-done most figures, and added many new ones. They are now in PDF format and a plugin or viewer is needed, for example, Adobe's free Acrobat viewer.
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The emission spectra given below were measured with a LiCor LI-1800 spectroradiometer, except for those marked `Macam SR´ which were measured with Macam SR9010-PC spectroradiometer. The LI-1800 is a single monochromator spectroradiometer that with the normal slit we used has a half bandwidth of xx nm. The SR9010-PC is a double monochromator spectroradiometer with a half bandwidth of xx nm. Both spectroradiometers were equipped with a cosine corrected light collector for these measurements. Data are expressed as spectral photon irradiance. In all cases the only light source was the one measured and no glass, plastic or other barrier was located in the light path unless it is indicated on the figure. In the case of the sun, the light collector was pointed directly towards the sun.
The spectra are shown for the range 300-900 nm, in spectral photon irradiance units. The sensor to lamp distance was different for different lamps, from about 1 m for discharge lamps to a few centimeters for light emitting diodes. The number of lamps varied: from a single lamp to banks of up nearly 100 lamps. Because of these reasons only the shape of the curve can be compared between graphs. The individual lamps measured are not necessarily typical as they have been chosen at random, most were new when measured but some had been in use before measurement. (In the future more detailed information on how each spectrum was measured will be added, but as the measurements have been done over a period of about 10 years measuring conditions could not be kept constant.)
It is also important to remember that there are small variations in the colour of the light emitted by lamps of identical type but from different manufacturing batches, and probably even more variation over longer periods of time as manufacturers sometimes `improve' their designs.
Author: Pedro J. Aphalo.