🙂 I often wonder how Lumens in LED fixtures are realy determined.. Because if i look at the whole salers data that provides the strip they only give Lumen data per (led) chip. Or per single LED if it concerns HP leds. But most aqaurium fixtures i've yet seen are SMD led. These excact same strips can be bought as single strip and the wholesaler states the factory data again per chip never per strip total. Say 65 lumen per led. And 1 metre strip contains 72 leds.
Is the total lumen equal to 65 x 72 = 4680 lumen? Does that mean if my fixture contains 2,5 metre total that i have 2,5 x 4680 = 11700 lumen?
I realy have no idea that's all i have..
How does the fixture manufacturer/assambler determine their products end performance?. Do they use the LED factory data per chip and add it all up like above to give us a number. Or do they actualy have a test device to accurately come up with lumen specs? If so than why not come with PAR, than they would come with something usefull. Because an aqaurium light assambler should know by now, that lumen doesnt do much for the fanatic plant nerd, they want to know PAR performance. Than why buy and use a lumen test device and give us data we don't realy want?.
I find that suspicious.. I hunges me towards the thought.. They just give us the added sum per chip, nobody can check it accurately with household equipment anyway.
I've noticed with cob led fixture, the LED used has a factory spec of 10 watts and 900 lumen.. And the fixture with driver in it and all states the same specs. Than i hook it to a measuring device and its performance is 20% less than stated. The driver has a build in rectifier that looses 20% power. Thus the LED is indeed 10 watt, but it uses and delivers only 8 watt. Obviously the assambler selling the fixture didn't test it, puts the led factory specs on the box and ignores the power loss from the driver. Thus it never ever can be 900 lumen at 8 watt consumption. When i bridge the rectifier it burns brighter..
We are taken for a ride here.. 🙂
