How to Measure an LED Millicandela (MCD)

The brightness, or luminosity, of a light bulb is usually measured in candela. With the invention of the light emitting diode, or LED, candela was not an accurate enough measuring tool. A single LED wasn't able to emit a full candela and scientific measuring tools had advanced to a stage where they could measure 1/1000 of a candela, or a millicandela. The tricky part of measuring an LED light source is that the angle the light is measured from has bearing on the output registered because an LED is a focus beam.

Things You'll Need

• Light meter

Show More

Instructions

1. • 1

     Turn on the LED light.

   • 2

     Turn on the light meter and wait for it to calibrate. This can take anywhere from 10 seconds to a full minute depending on the model of meter. This calibration measures the ambient light in the room.

   • 3

     Place the light meter one foot above the LED light source at a 0 degree angle and take a measurement.

   • 4

     Move the light meter to another angle and take a second reading. Continue this process until you have five or six readings. The highest reading that you take will be the LED millicandela for that LED.