-> taking the numbers from their Example 1 on page 19, i get pretty much the 
-> proper answer they get... 
 
-> theirs == p=29.7, T=75, T'=65.5, U=0.603 or 60.3 percent 
 
->   mine == p=29.7, T=75, T'=65.5, U=0.6025655547 or 60.25655547 percent 
 
-> close enough for me and with rounding, it is 60.3  
  
Just for fun, I put the same temperatures into the little BASIC program 
I posted here yesterday. I changed the barometric pressure to 100.6 
kilopascals, which is close to 29.7 inches of mercury. The program 
calculated the relative humidity to be 60.35 percent. So that's very 
close to the two answers found by other formulae. 
  
I guess the question is, how accurate does Herman need the calculation 
to be? And how will he know if it's right? 
  
                            dow 
--- Platinum Xpress/Win/WINServer v3.0pr5