Some years ago, I have try to mesure the shift of Thorium/Argon lines on my eShel spectrograph (without any temperature regulation, just ambiant air).
You can find here the result : (sorry this page is in French only...)
http://o.garde.free.fr/astro/Spectro1/L ... -Shel.html
Now my spectrograph is inside a cooler wine cellar with a PID regulation :
http://www.spectro-aras.com/forum/viewt ... f=8&t=1141
The regulation now is about +/- 0,1°C but I have not yet done any measurement to check drift with this thermal regulation.
For beter accuracy, I use also Th/Ar line with 4 digit after dot (comme from Harps spectrograph)
And I will try (as soon as possible) an exo-planet like Tau Boot with this set up to check if I can have good result
But I know is it possible, Christian Buil had done this kind of measure a few years ago with an eShel spectrograph :