Development of a Non-Contact Conductance Meter Using a High-Frequency Resonant Circuit.

DOI Web Site 16 References

Bibliographic Information

Other Title
  • 高周波回路を用いた非接触電導度測定器の開発
  • コウシュウハ カイロ オ モチイタ ヒ セッショク デンドウド ソクテイキ ノ

Search this article

Abstract

An apparatus for determination of the conductance of liquid foodstuffs without using electrodes, and consequently, without electrochemical influence of the electrodes has been developed. It comprises a radio-frequency resonant circuit, a solenoid coil for a measuring cell and a digital multimeter. The resonance magnitude (Ir) of the circuit, which reflects the electromagnetic loss of conductive materials put into the cell, was used for the index of specific conductance (κ) of the liquid foodstuffs. Using the aqueous solutions of NaC1 with various concentrations, relationship between κ and Ir at the resonance frequency of 10, 15 and 20 MHz was investigated. As the result, the minimum Ir and the maximum one in the Ir-κ curve were found at approximately 10-1 and 10 mS/cm, respectively. In addition, Ir-κ curves obtained from the solutions of KC1, NaOH, CuSO4 and citric acid were the same as that of the NaC1 solution. On the other hand, it was found that Ir was slightly decreased because of the presence of dielectric liquids such as ethanol, methanol or glycerol in the cell. Subsequently, when κ of uncertain samples were determined using the working curve predetermined, they were determined in the error of 4% on the average ranging from 10-2 to 102 mS/cm.

Journal

References(16)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top