This allows computation of A directly from the data In the 

 process of finding the curve G(r)/G(°o), it was necessary to find 

 the total area G(<&©) under the intensity curve g(r) The curves 

 appear somewhat as follows: 



The integral j [l~G(s)/G(oo)J ds is then the shaded area» The 

 value of A may also he obtained directly from G(oo) and the 

 corrected value of cr in the following manners 



-a. J Jfi P e & e IoiP/41 



7!-(R/o-r 



2= A fW-.r: . 



rWcr _ 



cr 



4 r 7T J^f- l c 



+ y +Uim) /sty 



e r i.(r)dr 



(K/Z<T) 



If the indefinite integral (l?/2.cr) J e" I Q (X)Jf is denoted 

 by S(R/ar), one obtains the equation 



A = 4,/^" -SUS^L • 



S(K/o-) 



In order to compute A it is necessary to have a table or graph 

 of the function S(R/cr). This is relatively easy to compute 

 from existing tables of the function e I (x) A graph of 

 S(R/oO for values of R/cr between and 4 is shown in Figure 10. 

 On the same graph, for comparison, is shown the corresponding 

 function for a square sampler, S(R/cr) s (<j/R) f£ /<r e~f* /2 -J/* ' 

 Since intensity data, in this report, are given nondimensionally 

 as fractions of the original dye solution, A will have the dimen- 

 sion of square inches. _ 



