I was trying to check the wattage of an LED bulb. How to know manufacturer's spec is correct?
closed as too broad by PlasmaHH, brhans, Bimpelrekkie, Harry Svensson, Leon Heller Jun 27 '18 at 14:59
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How to know manufacturer's spec is correct?
You confirm it by measurement.
You could also use a cheaper equivalent like this one:
But it will probably be unable to accurately measure the 1 W of your bulb.
But what are you hoping to gain by knowing if a LED bulb meets its specification? It either emits enough light or it does not. If it is a bad design it will get warm and probably not last long. For me amount of light and heat output (and related to that: lifetime) are more important in a LED light bulb then a specification on a piece of paper.
You can use a multimeter to measure the forward voltage of the LED. Then measure the current being drawn by the LED.
You can calculate Wattage by using:
W = A x V
It should generally be close to what the manufacturer specifications are if you are providing it a typical voltage.