This is the text-alternative version of Testing LED Color-Tunable Products.
One of the points of the CALiPER exploratory work with color-tunable luminaires was to figure out if conventional photometric testing is adequate for getting the information about the performance of the luminaire, and whether the photometric lab knows how to wire up the luminaire and get information on spectral power distribution at different points in its output.
The answer is it's pretty complicated. With dim-to-warm luminaires, it's fairly easy to just have one controller that controls both CCT and output, so those are more straightforward. You simply test them at different levels of output. Once you get to white-tuning luminaires, you're going to need to test it at multiple points in its light output and its color range. You’re going to have to test it at different points, not just one point, which is what is conventionally done.
LM-79 is a procedure for testing fixed-color, fixed-output luminaires, and it does a great job. However, for color-tunable LED luminaires, we need to take LM-79 to the next step. We need to have testing that looks at the performance of the luminaire at different points in its color range and at different points in its output range.
So for example, we may want to know what the spectral power distribution is at its warmest point, at a midpoint, and at a cooler point, so that we can tell specifiers what kind of color spectrum they can expect at those three different points.