An Unbalanced A.C. Bridge with High Voltage Source for the Conductometric Determination of Sulfur in Iron Ores

일정전류 비평행교류브릿지에 의한 전도도측정과 황의 정량

  • Czae, Myung-Zoon (Department of Chemistry, Sung Kyun Kwan University and Department of Chemistry, College of Liberal Arts and Sciences, Seoul National University) ;
  • Choe, Gyu-Won (Department of Chemistry, Sung Kyun Kwan University and Department of Chemistry, College of Liberal Arts and Sciences, Seoul National University)
  • 채명준 (성균관대학교 화학과${\cdot}$서울문리대 화학과) ;
  • 최규원 (성균관대학교 화학과${\cdot}$서울문리대 화학과)
  • Published : 19701200


A simple and convenient device for deflection-type direct reading the variations in electrolytic conductance is described and applied to the analysis of sulfur by combustion-$H_2O_2$ oxidation method. The apparatus consisted of a high resistance-ratio bridge in which the other adjacent arms are the differential cells. By adopting unusually high a-c voltage source for the bridge excitation, the a-c method for unbalanced bridge is established, decreased sensitivity owing to reduced bridge factor, 0.01, is overcome and also the absolute sensitivity and linearity are greatly improved. Over 50% variations in impedance of the balanced cell, within 1% deviation from the linearity can be attained with a volt (rms)order of output which was detected directly with VTVM without further amplification. Analysis of the bridge shows that these useful features are natural result of the constant current character of the high source impedance generator and the performance of the device agreed with the theoretical predictions. A standard procedure for the rapid analysis of sulfur using the bridge is also given, the analytical accuracy was approximately 1%. A determination takes not more than 5 minutes.



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