ELECTRODE EFFECTS 



567 



beveled on the outside as in Fig. 2-A to a tliickness of 1/G4". Ring 

 No. 3 was cut from phenol hbre sheet j g" thick and had a radial 

 width of ^s"- Since rubber tubing of the desired size was not avail- 

 able the rubber rings were somewhat smaller than 43.2" in diameter 

 l)Ut in all cases the foil electrode with which thev were used was cut 



OZ 03 Ot 



TH/CKNE35 - JA/CHf:3 



Fig. 4 — Percentage edge correction for samples 6 inches square with foil electrodes 

 upper, 4^-2 inches diameter, lower, 6 inches square 



to exactly the same size as the inside diameter of the ring and the 

 results were reduced to the equivalent value for XYi' diameter. 



In this test in order to simulate the depth of the mercury without 

 changing the electrode contacts, the lower part of the inner surface 

 of the ring was coated with foil to a height equal to the assumed 

 depth of the mercury. This was taken as Y^' in each case which is 



