On Mon, 10 Feb 1997, emanders wrote:

> THE PROBLEM:
> We study living cells and have some problems with temperature
> controlling. It seems that a variation of less than 0.1 degree C influences the
> focal depth too much. The focal depth changes sometimes 0.5 um.
I've seen something like that happening with a chamber that was heated by
an electric wire. The low thermal inertia of the system apparently caused
the metal chamber to dilate when the heater turned on.
Probably water circulation would be better because of the higher thermal
inertia. But in this case vibration may be a problem.
Try turning the heater off during scannings (if these are short).
Also a heated chamber in a cool environment may cause the heating system
to constantly turn on/off. A warmer room may help.

Regards

Carlos