Second try at a reply:  When I first aquired a 932L, I experimented with an lcd digital thermometer.  I found that the reflective surface caused viewing problems, especially in the infrared (see in the dark) mode.  I then bought an analog thermometer with a big indicating needle, bolted to the plenum of the furnace.  This seems to work well; at least until today when a firefox update screwed up the java needed to view the camera in mydlink.com.  I will post about this in another thread.
Regards,
Bob