measured curves would no longer be constant It is possible 

 to compute this effect for the case of a circular Gaussian error 

 surface and a circular sampler. It has been shown above that 

 the altered distribution curve will be 



r)=^ 



7Tft' 



€ 



2c 1 



" 2 W V^u^)H/> 



Then 



-<X> 2 , f % -/3% 



= A w : C s '^ 





&*J 



/* 



-A 



Hence , the volume under the intensity surface is not changed by 



the sampling procedure., It is of some interest to note that 



this is not the case with a square sampler A simple calculation 

 shows that 



["jMlnrJr = rrA P^jf [ (E + f )Pf|) + p($)] 



where p(.x) and P(x) are the functions defined above e This function 

 has a very flat maximum of one at R/cr 3 0, has scarcely deviated 

 from this value at R/ cr si and approaches tt/4 as R/<x -* 00 . 



In order to find the value 0" o it was necessary to plot 

 from the experimental data the curves G(r)/G(co) It would be 

 convenient if this work could be used to estimate the constant 

 A and to verify if possible its constancy as the value x, the 

 distance downstream from the injector^ varies Integrating 

 JoSg(s)ds by parts, one gets 



f Git) -J>Ws = £t m-6(s)Us = $(*■)£[/ - ff J J* . 



Consequently, 



- 11 - 



