On Tue, 28 Jun 2005, Peter Kravtsov wrote: > Hello Peter, > > Our humidity graph is corrected to 17 bar pressure of course. > I took the saturation vapor pressure from reference book for > different temperatures, and fit this dependence. > The complete formula for calculating ppm from T_dewpoint is: > ppm = 10^(-43.42291 + 0.43575*T - 0.00149*T^2 + 0.00000188204*T^3) > This formula works for 10 bar hydrogen. > To correct the result for 17 bar, I simply divided it by 1.7. > Is it not right? Dear Peter, I compared your equation with the Kahn calulator and the rubber bible (Handbook of chemistry and Physics). Your equation seems to be somewhat off the other references. But this does not make a big difference. (see attachment). There is not pressure dependence in the Kahn calculator with is obviously wrong. Regards Peter
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dew.jpg
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