Auxiliary
lamps are available for use in more demanding lamp flux measurements
when the absorption of the test lamp must be considered. Labsphere
recommends the use of an auxiliary lamp for situations where
the physical configuration and characteristics of the test
lamps differ from those of the calibrated lamp. The throughput
of the sphere varies given such differences in lamps, and
an auxiliary lamp corrects for these differences by providing
a means of correcting for lamp absorption.