Hi Bird...
- very impressive! I guess this setup is easier to implement for a newtonian with access from rear compared with cassegrains (even mine which is open at front is sealed at rear). Had a thought though that perhaps some useful data could be created for these scopes through experimentation and then relating experimenal results back to real-time log of temperature just on the outside tube surface (avoiding need for cable to intrude into the scope etc). In other words setup/attach sensors temporarily on mirror, inside tube and outside etc and then expose the scope to a range of temperature profiles, recording the results. From this it might be possible then to come up with some "scope-specific" data to predict when a mirror's temp would be close to ambient air temp simply through extrapolation of the outside tube temp profile. Nowhere near as accurate as a real-time inside/outside measurement setup as you have, but probably a lot more accurate - and specific to the users scope -than the simple rules of thumb many of us would use now (eg stick SCT outdoor for at least 1hr prior to us etc).
What do you think?
cheers,