Recognition of Gaseous Indoor-Air Pollutants using Multi-Gas Sensory System

The housing environment is changing with the change in the energy situation in Japan. The house is grad ually becoming an airtight structure to economize energy, and an indoor air-quality is going down. In this study, the gaseous indoor-air pollutants are recognized by a multi-gas sensory system using the OPS5 system which is one of the production systems. The sensory system has six gas sensors. Eight gases are selected as main indoor-air pollutants. They arecarbon dioxide, carbon monoxide, ammonia, propane, methane, cigarette smoke, ethanol and formaldehyde gases. The concentration of some of these will be calculated by the system. The sensor outputs are input into a computer every 4 seconds. The recognition processes are done in this interval and a specific kind of pollutant is identified. About twenty rules are employed in this system.