[volt-nuts] LTZ1000 project build

[Charles Steinmetz]

Lars wrote:

> if you have a completely sealed box with varying temperatures the
 > relative humidity in the box changes if the humidity is not close to 
zero.

As I have mentioned before, for many years I have put precision circuits 
that may be sensitive to humidity into gasketed metal boxes with fresh 
silica gel packets.  I have opened some of these after 2 and 3 decades, 
and even if there are some small leaks, or a vent hole to equalize 
pressure, the silica gel has still been fully dry.

This is an easy solution, and works extremely well.

I second the suggestion that the main drift problem in a DIY voltage 
reference (apart from the reference itself) is the resistors that set 
the scaling amplifier gain (or the DAC or PWM drift, if you go that 
way).  If you can live without scaling, by all means do so.

Best regards,

Charles