속도 계측형 호흡기류센서 설계를 위한 비균등 샘플링 기법

Abstract

Velocity-type repisratory air flow transducer measures dynamic pressure converted from air velocity based on the well-known Bernoulli's principle. It requires mutiple velocity smapling holes on the flow plane. Measurement error theoretically estimated by computer simulation was demonstrated to significantly reduce by unequally locating the velocity sampling holes. The flow plane was divided into multiple equi-area rings and the sampling holes were located on the circles also equally dividing each ring's area, which decreased measurement error down to 1/5 of the simple equi-radius ring division method. Also, less than 1% relative error was estimated with 4 or more sampling holes. The present technique was less sensitive by <1/2 to the velocity profile change compared to the euqi-radius sampling. Therefore, the present unequal distance velocity sampling technique should be of great use to design the structure of the velocity-type respiratory air flow transducer.