Dew Heater seting


Roman Hujer
 

Dear Howard Could you please explain how the Spam and Zero values work in the DewHater settings ? I couldn't find it in the wiki. Thank you
Roman


Howard Dutton
 
Edited

The goal is to scale the dew heater power (PWM 0 to 100%) to keep dew from forming on an optical surface while not wasting energy or overheating the surface and disturbing seeing.

The scaling is based on the temperature differential between the spot temperature (ideally near the optical surface but even just the ambient temperature if that's all you have) vs. and the dew-point temperature.  A differential near or below 0 deg. C means dew may start forming.

The Zero temperature differential setting is where power is at 100%.
The Span temperature differential setting is where power is at 0%.