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 aflowmeter in the periphery of a microcontroller, tomeasure air and O2 flows, in the range 0-50 lpm, inmedical device applications . The accuracy of the readingsis 2% at maximum and the reproducibility is better than0.05% in the range 5-50 lpm..The accuracy for flow measurements below 5 lpm. can beimproved by using a different airway resistor with asmaller orifice diameter. The cost of the flowmeter isaround 250 $.