Detection principle – RKI Instruments SD-705EC User 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