US Patent 7341694 Ammonia sensor

In an ammonia sensor (1), lead portions (7) and (9) are provided on an insulating substrate (5); a pair of comb-shaped electrodes (11) and (13) are connected to the lead portions (7) and (9), respectively; a sensitive layer (15) is provided on the comb-shaped electrodes (11) and (13); and a protective layer (17) is provided on the sensitive layer (15). Particularly, the sensitive layer (15) is formed of a gas-sensitive raw material predominantly containing ZrO2 and containing at least W in an amount of 2 to 40 wt. % as reduced to WO3.