5) Sensor diagnostics can be monitored for Light and Signal values to see
any degradation.
"Light" is the % of power output the Lamp is producing as a function of its
maximum output of 100%.
"Light" changes to keep the amount returning to the CCD to a level that is
not too bright or not too dim for the CCD to read.
Light increases, and once Light becomes 100%, then the system no longer is
in control and will result in Error ' (NO signal) if the CCD gets to say
below 20% or so...