PHOTOELECTRIC DETECTORS 



(A 



E 

 x: 

 o 



a 



75 



c 



C 



100 200 



Illumination 



300 AOO 



fool- candles 



Figure 28.37 Relationship between illumination and change of internal 

 resistance for a 45 mm diameter Weston barrier-layer cell 



900 



800 



700 



5-600 



O 



t, 500 



i> 

 a 



E AOO 

 ns 

 I 

 o 



.y 300 



200 



100 



50 



100 



150 



200 250 

 Foot-candles 



Figure 28.38 Relationship between illumination and current output for a 

 45 mm Weston barrier-layer cell 



369 



