LIGHT SOURCES AND DETECTORS 



< 



c 



0» 



3 

 U 





50 



100 150 200 



Cell voltage (no load) 



250 



300 



volts 



Figure 28.42b Output data of a Mullard 61 S V lead-sulphide cell. Cell current 

 plotted against no load cell voltage 



o 



300- 



200- 



4; 

 Mi 



"6 



2 



15- 



10- 



100- 5- 500 



OJ OJ 



> 

 c 



ID 



1.500 



1000 



49/iW from a 200 'C 473'K black body 



Interruption frequency 800 c/s 



Amplifier band-vi/idth 50 c/s 



Voltage across cell and 1 Mil Series load 200V 



-60 



-AO 



-20 



Temperature 



AO 

 C 



Figure 28.43a Signal conversion factor plotted against black body temperature 

 or a 61 SV Mullard lead-sulphide cell 



374 



