RKI Instruments SD-705EC - Manual (Page 37)

PT2E-1140
８−２ Detection Principle
The detection principle of this gas detector is electrochemical method. The sample gas is
electrolyzed by the electrochemical cell added with bias voltage and detected from the
electrolyzed current generated at that time.
The electrochemical sensor is designed to keep the interface between electrode and
electrolyte at a constant potential(Bias voltage) and is the method to electrolyze gas directly.
Then as the gas has the bias voltage generating its own electrolyzation(oxidation-reduction
potential)the bias voltage of sensor is determines by the oxidation-reduction potential.
WE: Working electrode
CE : Counter-electrode
RE : Reference electrode
Output
Potentiostat
circuit
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