Combustibles analyzer

A combustibles sensor apparatus operative in a monitored combustibles gas environment to measure the combustibles constituent content, comprising,

• an adapter having a means defining gas limiting aperture,
• means for establishing diffusion of a combustibles constituent of interest from a monitored combustibles gas environment through said aperture, wherein said means for establishing diffusion of said combustibles constituent through said aperture includes a solid electrolyte electrochemical cell having an oxygen ion conductive solid electrolyte and first and second electrodes disposed on opposite surfaces thereof, said solid electrolyte electrochemical cell combined with said adapter to form an internal chamber having communication with said monitored combustibles gas environment through said aperture, said first electrode being exposed to said internal chamber, a source of oxygen being provided at said second electrode to establish an oxygen differential pressure across said solid electrolyte electrochemical cell resulting in the transfer of oxygen from said second electrode through said solid electrolyte to said first electrode to combustibly react with said combustibles constituent diffusing through said aperture and thereby establish a differential partial pressure of said combustibles constituent across said aperture to maintain diffusion of said combustibles constituent from said monitored combustibles environment through said aperture, said solid electrolyte electrochemical cell producing a current in response to said transfer of oxygen, the size of said aperture being such that the current is proportional solely to the diffusion rate of the combustibles constituent through the aperture, and
• means for measuring the current of said solid electrolyte electrochemical cell as an indication of the combustibles constituent content of said monitored combustibles gas environment.

A combustibles sensor apparatus operative in a monitored combustibles gas environment to measure the combustibles constituent content, comprising,

• an adapter means having a means defining gas diffusion limiting aperture,
• means for establishing diffusion of a combustibles constituent of interest from a monitored combustibles gas environment through said aperture, wherein said means for establishing diffusion of said combustibles constituent through said aperture includes a solid electrolyte electrochemical cell having an oxygen ion conductive solid electrolyte and first and second electrodes disposed on opposite surfaces thereof, said solid electrolyte electrochemical cell combined with said adapter to form an internal chamber having communication with said monitored combustibles gas environment through said aperture, said first electrode being exposed to said internal chamber, a source of oxygen being provided at said second electrode, means for supplying DC voltage source connected across said electrodes of a magnitude and polarity to cause said solid electrolyte electrochemical cell to transfer oxygen from said second electrode through said solid electrolyte to said first electrode to combustibly react with said combustibles constituent diffusing through said aperture and thereby establish a differential partial pressure of said combustibles constituent across said aperture to maintain diffusion of said combustibles constituent from said monitored combustibles gas environment through said aperture, said solid electrolyte electrochemical cell producing a current in response to said transfer of oxygen, the size of said aperture being such that the current is proportional solely to the diffusion rate of the combustibles constituent through the aperture, and
• means for measuring the current of said solid electrolyte electrochemical cell as an indication of the combustibles constituent content of said monitored combustibles gas environment.