19 



B. LEAD CORRECTIONS 



The measured electrical resistance of the shielded leads from the con- 

 ductivity bridge terminals of the closure is A6 +0.02 ohm. The resistance of 

 the leads of the conductivity cells was calculated from their length and handbook 

 values of the resistivity of No. 24 platinum wire . The lead corrections thus ob- 

 tained for each cell are summarized in Table II . The dependence of the lead cor- 

 rection on temperature and pressure is negligible . 



TABLE II 



LEAD CORRECTIONS (25° C) 



Cell 



Leads and 



Closure 



(ohm) 



Length of 

 Pt Leads 

 (inches) 



Total 

 Pt Leads Correction 



(ohm) 



(ohm) 



Teflon Jamieson 

 (TJC-1) 



0.54 



10 



0,12 



0.66 



Glass Capillary 

 (GCC-1) 



0.54 



13 



0.16 



0.70 



Glass Capillary 

 (GCC-2) 



0.54 



11 



0.14 



0.68 



by 



The resistance of the solution-filled conductivity cell, R ' , is given 



R ' = R - L, 

 c m 



(1) 



where Rj-^^ is the resistance as measured on the bridge, and L is the appropriate 

 total basis correction from Table n . 



C. CELL STABILITY 



Considerable shielding and grounding difficulties were encountered, but 

 have been for the most part removed. In particular, the conductivity bridge and 

 the manganin cell recorder were interfering with one another . When the cell is in 



;artliur B.littleJnt. 



S- 700 1-0307 



