How does one get 500 liters per minute (LPM) into a 0.05-liter bag? This paper will discuss how to achieve theaggressive medical market requirements for a family of flow sensors and how to reconcile these requirements withthermal to electronic silicon based microstructure sensor technology. Goals for this device include: minimal powerconsumption, fast response time, minimal pressure drop at full scale, minimal repeatability and hysteresis errors,
and, above all, small package size. In developing the Honeywell prototype, the greatest challenge that wasovercome was the tradeoff between high flow rates and small size. The flow must be kept laminar within the entireoperating range. This paper will discuss the technology chosen, the history of the technology in this market, theanalysis, modeling andexperimentation that proved a viable concept and the initial product development that
resulted from these efforts.