How to distinguish between LEDs

Thread Starter


Joined May 9, 2016

I want to know what kind of tests can be done to distinguish between two leds of the same color, but with different characteristics (like luminous flux, for example).

Thank you.


Joined Oct 15, 2009
What are you trying to do?
For luminous flux you would power both LEDs with the same fixed current and measure which is brighter..

When powered you can also determine the forward voltage rating of each by measuring the drop across the LED..


Joined Nov 30, 2010
When I needed a measurement of light intensity, I used a Minolta SLR camera.
I had to weasel my way through some references to translate F-stops into lumens, but it's possible.
On the other hand, you can probably get a light meter a lot cheaper than buying a whole camera.:D


Joined Aug 23, 2012
If you want to get a more accurate value of Luminous Flux then you can buy the Luminous Flux Meter, or you just want to do a general judge not that accurate, you can using a LDR + voltage divider + op amp positive amplifier.


Joined Sep 9, 2010
Put all your test LEDs in series with a current-limiting resistor. They'll all have the identical current. Then just look at them.