BSSLED sets a new world record for L70 of 5,050,000 hours for their 100w Floodlight.

Is this a late April fool’s joke, no? Is this a load of nonsense, well yes?

The light is real and so is the test report which is an In-Situ Temperature Measurement Test used to calculate lumen deprecation (part of the qualification process for government rebates). The test was carried out in Australia by a NATA approved laboratory in accordance with IES TM-21-11 test procedures. So how did we get a figure of 567 years before the LED's in the luminaire depreciate by 30%? Well, the simple answer is that once the operating temperature of the LED's had been established then extrapolation methods were used to calculate the intersection of the deprecation curve with 70%. The erroneous results in this case arose due to the behaviour of the LED during the TM-21 test. At some point, close to the end of the 6000-hour test the lumen output of the LED became stable producing a very flat curve. When this curve was extrapolated, it gave us the erroneous results.

The point of this article is to point out that just because someone says they have a test report it doesn’t necessarily mean that it is either true or can’t be challenged. All results should have a sanity check carried out to see if they make sense in the real world before they are published.

PS we are still proud of the fact that at 40 degrees ambient the LED junction temperature was only 59.3 degrees.