Elektrické měření účinku světla na desku fotografickou. 



45 



Measuring of the potenciál différence. 



The potenciál différence between two halves of the samé plate 

 one half being exposecl to the light the other not, was measured by 

 compensating it with a Leclan che- cell, using an Ostwalďs rhéostat 

 and bridge-viree with a capillar-electrometer as indicator. The method 

 was very sensitive showing distinctly a différence of 0002 volt. 



The wet plates (Schleussner's) were exposed to the light of an 

 Auer-burner and arrangea as above. It was possible to measure the 

 potential différence ten minutes after the exposure. The results are 

 in Table 3. 



Table 3. 



Exposure 1 sec. 



T 



min. |10~ 4 volt 



°C 



Exposure 5 sec. 



T 



t 



min. 1 0" 4 volt °C 



Exposure 15 sec. 



T 



min. IlO" 4 volt 



t 



Exposure 30 sec. 



min. 10-* volt °C 



10 

 13 

 22 



43 



60 



230 

 384 

 330 



328 



22-9 



22-8 



10 



24 



38 



48 



67 



84 



101 



117 



166 



201 

 344 

 429 



478 

 582 

 612 

 578 

 552 

 508 



22-7 

 22-8 



22-9 



23-0 



10 

 30 



47 



70 



87 



121 



153 



182 

 421 

 516 

 589 

 591 

 384 

 274 



22-5 



22-6 



22-8 



10 



257 



24 



446 



39 



553 



71 



622 



93 



614 



L41 



541 



161 



420 



290 



167 



22-5 

 22-6 



22'7 



Exposure 60 sec. 



T 



min. ur 4 volt ° C 



Exposure 120 sec. 



10-*volt 



°C 



Exposure 30C 



sec. 



T \ e t 



min. 



10" 4 volt 



o p 



Exposure 600 sec. 



T 



t 



10- 4 volt| U C 



10 



28 

 45 



188 



443 



237 

 121 

 265 



237 



23-9 



10 

 18 

 35 

 51 

 68 

 86 

 115 

 136 



-527 



— 410 



— 377 



— 348 



— 337 

 -325 



— 92 

 + 110 



237 



23-8 



23-9 



10 

 25 

 32 

 49 



454 

 294 

 138 

 149 



21-2 



10 

 23 



49 

 80 

 99 



— 614 



— 126 



— 109 

 + 17 

 + 233 



21-3 



21-5 



