May CoSO4.7H2O be desicated at room temperature without loss of the
waters of crystalization?  This material is quite hygroscopic, and I
need a way to keep the material at its formula weight, without
adsorbed atmospheric water.

yo lizardbreath, pardon my chemistry but isn't dessication a process
to make a compound loose its water?

but if you are thinking about keeping a dry environment, you might
have a problem, as if you keep it too dry the water could
dissociate...

maybe u want to dry to build a simple dry chamber using other
hygroscopic compounds i.e. use other compounds that are more
hygroscopic than cobalt sulfate to take away the atmospheric water.

That is the issue...to remove non-specifically adsorbed water without
removal of the stoichiometrically bound water.  The formula weight
includes the latter but not the former.