I 2 3 4 5 6 7 8 



10 



Rt=l4-. 



/ e = od 



P 

 P 



Figure 14-11. Response of normal device. 



The lower part of the figure shows a resistive layer thinner than the spac- 

 ing. This instance is characterized by a depression opposite the layer and two 

 symmetrical small peaks, c and d, on each side of the depression. This feature 

 illustrates the main disadvantage of the normal device: i.e., beds thinner than 

 the spacing, no matter how resistive they may be, appear on the logs as being 

 conductive. 



289 



