QUALITY OF SUPERHEATED STEAM. 123 



Appendix XVII., 1885 Code, with some differences in nota- 

 tion, 



- 



. . (6) 



The value Q applies when the second .term is less than 

 unity. P may be derived therefrom by substitution in equa- 

 tion (2) and F from equation (4). 



<2 4 applies when the second term of the above equation is 

 greater than unity, which shows that the steam is superheated, 

 and, as in this case, the heating value of the superheat has 

 already been measured by heating the water of the calorim- 

 eter; the proportional thermal value of the same, in terms 

 of the latent heat Z, is represented directly by Q l i, and 

 we have as the factor of correction for the quality of the steam 

 with superheating, 



(7) 



See also equation (5). 



When .the quality is greater than I, or equals Q l , the num- 

 ber of degrees of superheating, 



-i). - - (8) 



THE QUALITY OF SUPERHEATED STEAM.* 



The quality of the superheated steam is determined from 

 the number of degrees of superheating by using the following 

 formula : 



_ Z + o. 4 8(7*-/) 



* G. H. Barrus in Report of Committee on Boiler-tests, A. S. M. E., 

 1897. 



