kingofnobbys
BD.org Sicko
Not obvious, but the best approach is to control the warm and cool zone temperatures via the a thermostat whose probe placement is dangling somewhere in the cool zone, this will, as a consequence of the physics result in control of both the warm and cool zone temperatures.
Get the cool zone temperature controlled, the warm zone temperature will follow because of natural thermal air circulation and being closer to the radiant heat source (the basking globe).
For those with a physics or engineering bent :
https://www.engineeringtoolbox.com/radiation-heat-transfer-d_431.html
deals with the basic principles of radiant heat transfer from a heat source to a surface at a given distance and orientation .
Distance law
http://bsche.blogspot.com.au/2009/09/inverse-square-law-of-heat-unit.html
https://www.engineeringtoolbox.com/convective-heat-transfer-d_430.html
and
https://www.engineeringtoolbox.com/convective-heat-source-d_1007.html
deals with basic principles of heat transfer via a fluid (air) .
Get the cool zone temperature controlled, the warm zone temperature will follow because of natural thermal air circulation and being closer to the radiant heat source (the basking globe).
For those with a physics or engineering bent :
https://www.engineeringtoolbox.com/radiation-heat-transfer-d_431.html
deals with the basic principles of radiant heat transfer from a heat source to a surface at a given distance and orientation .
Distance law
http://bsche.blogspot.com.au/2009/09/inverse-square-law-of-heat-unit.html
https://www.engineeringtoolbox.com/convective-heat-transfer-d_430.html
and
https://www.engineeringtoolbox.com/convective-heat-source-d_1007.html
deals with basic principles of heat transfer via a fluid (air) .