On Mon, Jul 18, 2011 at 9:34 AM, Jouni Valkonen <[email protected]>wrote:
> 2011/7/18 Jed Rothwell <[email protected]>: > > P.J van Noorden wrote: > > > >> It is very important to notice that water boils at 100.5 C when the > >> outside air pressure is 1030 mBar, which can be the case when a high > >> pressure system is covering Italy . . . > > > > In the April 28 tests, Lewan reported: "we calibrated the probe by > immersing > > it in a pot with boiling water, and the measured value was then 99.6 > degrees > > centigrade." Later during the test they measured vapor at "about 100.5 > > degrees centigrade." There is no doubt that was vapor, since it is > > substantially hotter than the boiling water, plus you can see steam > coming > > out of the pipe. I expect that backpressure is minimal with this system. > > > > Oh, I have constantly talked that the measured boiling point of water > is 99.7°C. Apparently my memory did error as I meant that boiling > point according thermometer is 99.6°C! Notice that absolute accuracy > of thermometer is ±0.4°C. Although it's relative accuracy is ±0.1°C. > This alone proofs that there is considerable amount of pressure build > up and pressure can only be build up if there is lots of dry steam > present. > You're just guessing. The pressure at 30 cm of water is enough to raise the bp by about a degree. The chimney height can explain it.
