REFLECTOR: Low Fuel Warning Sensor False Reading: SOLVED?

[Brian Michalk]

An update to those of you using an optical fuel level sensor.

I had installed the Carlo Gavazzi sensor from McMaster Carr ( 
http://www.mcmaster.com/#liquid-level-sensors/=rqf988 ) because it's a 
solid state optical sensor that should never wear out.

I have had problems with it falsely indicating a low fuel situation in 
the sump.  Finally yesterday while flying I deduced that whenever I flew 
west towards the sun, the low fuel light would illuminate, and when I 
flew east away from the sun, the light would extinguish.

The manual does say the device doesn't work in sunlight, but I never 
considered bright light to be the culprit.  I am going to fly with the 
sump covered with material to confirm my suspicions.  If confirmed, I 
will be painting the sump tank so that sunlight will not penetrate the sump.