David wrote:
I was thinking of holding the temperature right at 25C or maybe a
little higher at an inflection point to minimize the possibility of
condensation. The difficulty is that the ambient temperature could
vary above or below that so the TEC has to both heat and cool but that
is a solved problem.
On Fri, 13 May 2016 10:05:02 -0400, you wrote:
A problem I had with TE heater coolers was condensation when the
ambient temperature was higher than the TE temperature. I was trying
to operate the crystals on the lower temperature inflection point.
After a while, corrosion became a major issue.
John WA4WDL
The HP 3450A & B model digital multimeters used a Peltier device to control
the temperature of the voltage reference zener diode. You can download the
manual for the "B" model from Keysight's web site to get an idea of the
control circuitry
(http://www.keysight.com/main/techSupport.jspx?searchT=3450B&id=3450B:epsg:pro&pid=3450B:epsg:pro&cc=US&lc=eng).
There's also a sales bulletin for that model that gives a bit more
information about the Peltier device and chamber
(http://www.ko4bb.com/getsimple/index.php?id=manuals). Search for 3450A on
that site.
The chamber is controlled to 43C by the Peltier device, allowing quite fast
warmup times for the instrument, and operation above normal environmental
temperatures.
Cheers,
Dave M
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
