Temp Sensor placement?

[Jannerland]

With a view to triggering refocus as the temp changes through an imaging session I'm curious about where folks place the temp sensor used by the focuser / imaging software?

Is "just somewhere" on the rig to pick up changes in ambient temp the thing or should it be as close to the scope optics as possible?

Ta Rob

[Clarkey]

Personally I just tape mine to the OT. As long as it is measuring the change in temperature the exact measurement is not critical. As long as it is not near anything that produces heat like a camera or dew heater it should be fine.

[barbulo]

Welcome to SGL.

This could be a good place if you own a ZWO EAF.

[Jannerland]

Thanks both, that makes life easy..

[Carbon Brush]

My understanding is the glass can be regarded as fixed size/shape so can be regarded as constant FL.
However, an aluminium or steel tube does have thermal expansion.
Your sensor should be somewhere on the tube.
Obviously away from dew heaters, camera, etc.

A bit of heat transfer grease (used in electronics) and a cover over the sensor will help.
If you can sueeze it in a gap somewhere, great. Other use a cover.
The cover can be any insulating material. Old sock, insulating tape, etc.
It is only to keep the sensor in good contact with the tube and avoid dangling cables.

HTH, David.