533 



d is the charge-to-gauge distance, and 



m and n are consteoits determined by the properties of the 

 diapEraga 



The constants m and n were found not to be mutually independent, but 

 vere in the ratio of about 1:2 for both the copper and steel diaphragms. 

 For the copper diaphragms, m and n were about O.k and 0.8 respectively; 

 for the steel diaphragms, m and n were about 0.6 and 1.2 respectively. 

 Ihese values for the constant m were determined over a limited range of 

 charge weights, in most cases frc»i 1 to 10 lbs. Weight and distance 

 exponents determined from 300 and 600 pound charges and steel diaphragms 

 were approximately O.l^g and 1.13i3/. 



To illtistrate some of the uses of the damage Equation (?) let us 

 suppose that two explosives, A and B, are being conpared by rneams of 

 gauges emd using two different diaphraigm materials, 1 and 2. If we 

 fire one shot with each explosive for each diaphragm material, we laay 

 express the results by the following four equations 



D^. k^ilM^L. (8) 





/w \°2 



D^= k^_LJLL_ (10) 



(^A2)°2 



Db2= ^-V^T (^^^ 



If the experiment has been performed so that the charge weights and 

 distances were held constant for the shots represented by Equations (8) 

 and (9), and constant also for Equations (lO) and (ll), then damage 

 ratios for the two explosives will be obtained. 



13/ J. S. Coles, OSRD Report No. b2kO, NDRC Report No. A- 362. 



