Development of the solid state electrolyte type carbon dioxide sensor

Until now it has been hard to obtain sufficient quality in the solid-state-electrolyte type carbon dioxide sensor. This is partly due to the problematic quality of NASICON and partly because of its low humidity- resistance and thermal instabilities of alikali-metal carbonates used as the secondary electrode in the sensor. The novel NASICON material with good crystalline quality and higher sinterd density was preparerd. Thermal impact resistance were improved by using navel NASICOM. As for the sensing material, lithium carbonate being usually employed as the primary material, it has been modified to achieve better water-resistance and improved stability. This is done by adding alkaline-earth carbonate into lithium carbonate with mixing ratio of the two substances being about 1:1. These experimental results enable us to manufacture carbon dioxide gas sensor at a low production cost.