48 



BELL SYSTEM TECHNICAL JOURNAL 



Fig. 18 — Impedance bridge circuit showing the arrangement used in applying 

 testing potentials in quadrature. 



CO 8 

 gJ20 



> c 



10 



> 1- 



^^ 



1= ° 



S.^^0 



-30 



-30 -20 -10 10 20 30 



Degrees between Field Potential and Potential for Balancing r. 



Fig. 19 — Observed galvanometer sensitivities which are comparable to the 

 calculated sensitivities of Fig. 16. Sensitivity for unbalance in the component: 



I — R with the phase of testing potential applied for balancing R. 

 II — R with the phase of testing potential applied for balancing r. 

 Ill — r with the phase of testing potential applied for balancing r. 

 IV— r with the phase of testing potential applied for balancing R. 



