PROPERTIES OF STEAM AND AMMONIA 



specific heat measurements through the Clausius relation. In the at- 

 raovc these objections several equations have been developed 

 and the one finally chosen has the form 



That equation (B) satisfactorily represents the experiments is shown 1>\ 

 I, in \\hirh the points represent the experimental values transferred 



ooo 



80000 



100000 



01 Ml 



Pressure, kg. per sq.ra. 



Fta. a. ISOTHERMAL CURVES FROM EQ. (B). THE POINTS REPRESENT THE EXPERIMENTS 

 OF KNOBLAUCH, LINDB, AND KLEBE. 



to the pv-p plane, and the curves represent the equation with the various 

 o.n-t.mt \ allies c,f T indicated. 



The term c in the equation is not strictly a constant. Following the 

 suggestion of Callendar, this "co- volume" term is taken as the volume 

 of the liquid corresponding to the pressure p. Hence when the equation 

 is used to determine the volume of saturated steam the first member 

 I DM : - r*. that is, the increase of volume during vaporization. 



The following are the constants. 



English Units 

 (p in Ib. per sq. in.) 



log 5= T.77448 



log m = 10.82500 



log 30= 2.71000 



-4 n= 4 



Specific Heat of Superheated Steam. - - The experiments on specific 

 heat may be divided into groups as follows: 



1. The early experiments of Regnault with steam at atmospheric 

 pressure and at temperatures n I.itivdy close to saturation. 



2. The experiments of Mallard and Le Chatelier, Langen, and Pier 

 at very high temperatures. 



ric Units 

 kg. per sq. m.) 



log- 1.67213 



log m - 8.59929 



log 3^-3.28644 



