A LOW-COST MICROCONTROLLER BASED GAS FLOWMETER USING A SPECIALLY DESIGNED PARABOLIC AIRWAY RESISTOR

摘要

A parabolic airway resistor is designed and used as a flowmeter in the periphery of a microcontroller, to measure air and O2 flows, in the range 0-50 lpm, in medical device applications . The accuracy of the readings is 2% at maximum and the reproducibility is better than 0.05% in the range 5-50 lpm.. The accuracy for flow measurements below 5 lpm. can be improved by using a different airway resistor with a smaller orifice diameter. The cost of the flowmeter is around 250 $.