Patent ID: 6797151
Filing Date: 2004-09-28
Classification: G01N

Abstract:
A CO sensor which comprises a first measurement space in communication with a measurement gas atmosphere via a first diffusion-controlling section for introducing a gas under measurement into the first measurement space, a second measurement space in communication with the first measurement space via a second diffusion-controlling section, a first electrode disposed in contact with a first proton-conductive layer and located within the first measurement space, a second electrode disposed in contact with the first proton-conductive layer and located outside the first measurement space, a third electrode disposed in contact with a second proton-conductive layer and located within the second measurement space, a fourth electrode disposed in contact with the second proton-conductive layer and located outside the second measurement space, and a support for supporting the first diffusion-controlling section, the first measurement space, the second diffusion-controlling section, the second measurement space, the first proton-conductive layer, the second proton-conductive layer, the first electrode, the second electrode, the third electrode, and the fourth electrode, said CO sensor further comprising:means for controlling the hydrogen concentration within the first measurement space to a constant level by pumping hydrogen contained in the gas under measurement outside the first measurement space or by pumping hydrogen into the first measurement space upon application of a first predetermined voltage between the first and second electrodes, and means for obtaining a CO concentration of the gas under measurement based on current flowing between the third and fourth electrodes upon introduction of the gas under measurement having a controlled hydrogen concentration from the first measurement space to the second measurement space via the second diffusion-controlling section and application of a second predetermined voltage between the third and fourth electrodes.