A TWO ELECTRODE ELECTROCHEMICAL SENSOR FOR DETECTING TRACE PROPELLANTS IN AIR

摘要

The accurate detection of UIMH to its threshold limit value is achieved with a two-electrode-electrochemical sensor and a KI electrolyte. Three electrolytes are tested with two cells to realize this detector. The theory of electrochemical reactions in solutions is valid for this sea mor and the large capacitance is explained by the electric double layer concept. An equivalent electrical model is de-rived to optimize sensor response. A flow system and standard measuring instruments are used to obtain the experimental results. The electrochemical reaction between the cell and UIMH results in a decrease of overvoltage in proportion to the concentration of UDMH in air. Finally, a linear approximation of this reaction is obtained with a UIMH equivalent circuit.