FEASA LED ANALYSER
FUNCTIONAL VERSION 
Intensity
Intensity is a measure of the amount of light being emitted by the LED. The Analyser tests the
Intensity of each LED and outputs this value to the Test System. The value is output as a
number   in   the   range  0   -   99,999.   The   Analyser   is   calibrated   to   a   fixed   standard   and   all
measurements   are   relative.  The   Intensity   output  reading   is   NOT  part  of   the  International
System of Units and is not an absolute or traceable unit of colour measurement. It is part of
the Hue Saturation and Relative intensity (HSI) system of describing colour. 
The Analyser can be set in either Linear mode or Logarithmic modes to measure Intensity of
the LED.  The  units  are  shipped  from  the  factory  in  Logarithmic  mode.  See  set/   put   log     and
set/   put   lin     commands   to   determine   how   to   set   the   mode   of   the   analyser.   Use   the
get   intensitymode    command to determine which intensity measure mode the Analyser is set to
Factors that influence Intensity Measurement:
 The position of the Fiber in relation to the LED.
 Offset from the Optical Centre of the LED.
 The Gap between the end of the Fiber Light Guide and LED to be measured.
 The condition of the Fiber end.  It must be kept clean with a 90º Cleave.
 Is the LED Static or Flashing ?
 External Influences – Other LEDs in close proximity, Ambient Lighting.
 Is an Optical Head being used.
There are 6 capture ranges each with an intensity output range of 0 to 99,999. Feasa
recommends that the UUT readings should be in the 55K to 85K range for the best
stability.
Figure 3a. Intensity for the LED Analyser in LOGARITHMIC Mode
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