Amperometric sensor for low level dissolved gas with self-depleting sensor design

摘要

A dissolved oxygen sensor (10) having a cathode (34) and anode (54) immersed in an electrolyte (53) is designed to provide a low background current in the sensor (10) when a potential is applied to the cathode (34). The background current is maintained at a desired level by selecting the area (A) and length (L) of a channel or path (46) of diffusion of residual oxygen in the electrolyte (53) to the cathode (34). The area (A) of the diffusion channel (46) in relation to its length (L) is selected to be at or below a selected ratio, A/L.