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Flicker Measurement Data
Flicker Frequency
Is the flicker frequency of lamp typically caused by the driver and supplied AC current.
Flicker Percentage
Flicker percent is a relative measure of the cyclic variation in the output of a light source (i.e.
percent modulation). Sometimes this is also
referred to as the “modulation index.”
From the figure: Percent flicker = 100 x (A
–
B)/(A + B)
Flicker Index
Flicker index is a “reliable relative measure of the cyclic variation in the output of various
sources at a given power frequency. It takes into account the waveform of the light output as
well as its amplitude,” according to the handbook.
The flicker index assumes values from 0 to 1.0, with 0 for steady light output. Higher values
indicate an increased possibility of noticeable lamp flicker, as well as stroboscopic effect.
Again, from the figure: Flicker index = Area 1/Area 1 + Area 2
