Re: Is there a phenomenea that can force condensation at temps above dew point?

I can't think of any physical effect which would produce condensation at 
conditions above the dew point as you report.  I think it is more likely 
that this is a measurement problem or combination of measurement problems.

First, dew-point temperature is not a trivial thing to measure; unless you 
have a sophisticated and well-maintained chilled-mirror hydrometer, you 
will be doing well to get it correct within 1 degree Fahrenheit.

Probably more important, however, is the difficulty of measuring the 
temperature of a surface.  If you just take a thermometer end or a 
thermocouple and press it against the surface of the glass, you are not 
going to get an accurate reading (think of trying to take your temperature 
by sticking out your tongue and touching a thermometer to the end).  My 
guess is that the actual surface of the glass is a few degrees colder than 
what you report and that accounts for the condensation.

Allan Harvey, aharvey@boulder.nist.gov
"Don't blame the government for what I say, or vice-versa."