You could always use a TEC as the heart of a dewpoint sensor by optically sensing the temperature required for dew to form on a cooled mirror. In practice the temperature at which the dew vanishes is typically used. A collimated light beam together with a photodiode is typically used to sense the presence of dew droplets on the mirror.
Bruce > On 24 December 2020 at 08:57 ed breya <e...@telight.com> wrote: > > > This recent TEC talk reminded of some of my long term planned projects, > and related issues. I have at least four "someday" projects involving > TECs, to regulate device temperatures near or below "normal" room > temperature, including a high precision DC voltage standard, a sub-fA > electrometer circuit, a constant temperature block for nonlinear analog > computing elements, and a small general purpose heat/cool box for device > and circuit testing. Each has its own particular system, application, > and environment issues, but common to all is the lower limit of running > temperature, based on the local climate conditions and dew point. I plan > to estimate the lowest possible operating temperatures for expected > conditions, that avoids condensation, and not having to resort to > special packaging. > > An essential thing for this is a dew point calculator. I found lots > online, but this is my favorite so far. It's slider-based, so you don't > even have to enter numbers. > > http://www.dpcalc.org/ > > The harder part is finding the normal range of local climate conditions. > > Ed > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.