392 



E. A. POLYAKOV 



Avas placed on the surface of the solution, so that, the probe electrodes were 

 in the liquid, while their leads were in the air. 



The results of measuring the electrode coeflEcients in solutions of different 

 concentrations are given in Table 2. The coefficient for the arrangements 

 7 and 8 is evidently less than for the other devices. 



Table 2. Percentage increase of the coefficients of The electrical devices 



WHEN THE specific RESISTANCE IS MEASURED FROM 0.1 TO 20 D, m 



To determine the influence of the external medium, changes in the read- 

 ings of the electrode devices, on approach to a screen of insulating or conduct- 

 ing material, were taken. The results of these observations are given in 

 Table 3. 



Table 3. The least distance from the electrical device to the screen when 



THE influence OF THE LATTER IS NOT NOTICED 



L — the length of the probe; /• — the radius of the outer loop. 



(*) The screen is brought up to the outer loop. 



Table 3 shows that the arrangements 7 and 8 are again the least influenced 

 by the external medium, so that even when the screen touches the loops 

 the readings of these devices do not change. 



Obviously 7 and 8 are the most useful of the electrode devices shown on 

 Fig. 4. 



