A SHIELDED BRIDGE FOR INDUCTIVE IMPEDANCE 171 



Conclusion 



A system of electrostatic shielding for a direct reading bridge for the 

 measurement of inductive impedances at frequencies up to 50,000 

 cycles has been described. 



The general considerations defining the balances of the various 

 capacitances which this shielding controls have been discussed and 

 specific requirements derived for a typical range of impedances. The 

 physical construction of a bridge designed to meet these requirements 

 has been described and test data given illustrating its performance. 

 These have shown it to be capable of comparing impedances over the 

 above frequency range with a precision which approximates that 

 ordinarily found in routine direct current resistance measurements. 



