 Because of this temperature sensitivity, LED measurement standards, like IESNA’s LM-85, require that the junction temperature is determined when making photometric measurements.Junction heating can be minimized in these devices by using the Continuous Pulse Test Method specified in LM-85.An L-I sweep conducted with an Osram Yellow LED shows that Single Pulse Test Method measurements yield a 25% drop in luminous flux output and DC Test Method measurements yield a 70% drop.