58 



Over the pressure range 15 to 10, 000 lb/in. , 

 can be represented by a simple empirical relation 



the observed results 



^P,T, CI *^1,T, CI 



^Cl^ 



(15) 



that is to say, the specific conductance at any pressure in this range can be cal- 

 culated from the value at 1 atmosphere and the same temperature and chlorinity 

 and an additional term which is the product of a constant (for a given chlorinity) 

 and the pressure. With a further sacrifice in accuracy but gain in generality, in- 

 asmuch as this constant J C ci or A K/A P, appears to be a linear function of chlo- 

 rinity;, equation (15) can be rewritten 



K 



P,T, CI 



1,T,C1 



+ 1.17x10 CI P 



(16) 



where P is the pressure expressed in lb/in. 2. Although it is less accurate than 

 the original data, we believe that expression (16) will be of considerable practical 

 use to oceanographers . Equation (16) probably can be extended within reasonable 

 limits beyond the temperature (0 to 25° C) and chlorinity (9.68 to 19.376 0/oo) 

 ranges of the present experiments; however, it becomes increasingly inaccurate 

 as the pressure is extended beyond 10, 000 lb/in. 2. 



As the sea water is subjected to pressure, due to its compressibility 

 its volume will decrease, and thus the concentration of the electrolytes it contains 

 will increase. The specific conductance of a solution increases with increasing 

 concentration of electrolytic solute; however, as Table XIII and Figure 26 show, 

 the observed increase in specific conductance with pressure is much greater than 

 one would expect simply on the basis of the decreased volume of the solution. 











TABLE XIII 









COMPARISON OF CALCULATED AND OBSERVED SPECIFIC CONDUCTANCES 







(19. 



376 chlorinity. 



35.03 salinity 



sea water at 0°C) 













From 





From 













Empirical 



% 



Compress- 



% 





Pressure 



Observed 



Expression Deviation 



ibility 



Deviation 



(lb/in. ^) 



(bars) 







15 



1 



0.02906 



0.02906 



- 



0.0291 



- 



5, 



000 



340 



0.03020 



0.03038 



0.6 



0.0295 



2.3 



10, 



000 



690 



0.03125 



0.03171 



1.4 



0.0297 



5.1 



15, 



000 



1,000 



0.03218 



0.03303 



2.6 



0.0299 



7.2 



20, 



000 



1,400 



0.03325 



0.03436 



4.5 



0.0301 



9.6 



a . Observed data extrapolated to . 0° C = 



artbur a.littlcKnir. 



S-700 1-0307 



