Portable Engine Emission Analyzer

A strategic need exists for harsh-environment, foul-resistant engine exhaust emission sensors. No presently available devices combine the requisite sensitivity and selectivity to hydrocarbons, CO, CO2, and NOx with thermal and chemical robustness, low power drain, rapid response, and reasonable cost. Boston MicroSystems, Inc., proposes to develop a hand-held portable engine emissions analyzer that is capable of satisfying the U.S. Environmental Protection Agency's requirements. Boston MicroSystems, Inc.'s proprietary SiC micromachining and thin-film technologies are used to fabricate arrays of SiC microhotplates with integrated thin-film gas-sensitive semiconducting metal oxides. Exceptional gas species selectivity results from the ability to precisely control and rapidly cycle the microhotplate sensors to high temperatures using mW power levels and ms response times. The Phase I objective is to identify the optimum combination of film composition and thermal programming needed to achieve stable performance, high sensitivity to NOx,, and high selectivity relative to interference gases. A menu-driven, microprocessor-controlled analyzer will be designed for use in a portable, hand-held instrument. This instrument will fill the need for a reliable and robust portable exhaust emissions analyzer for automotive and aeronautic propulsion systems, power generation, and incineration applications.