Low Pressure Drop Oxygen Flow Meter for the PLSS

The portable life support system (PLSS) of the advanced extravehicular mobility unit (AEMU) provides the necessary environment for a crew member to operate within the space suit.nbsp; Within the PLSS, the oxygen ventilation loop provides carbon dioxide washout, gas temperature control, humidity control, and trace contaminant removal.nbsp; Historically, there have been issues with the measurement of air flow for the oxygen ventilation loop.nbsp; With the Apollo EMU, there were humidity issues with the implemented flow meter.nbsp; For the Space Shuttle/ISS EMU, the flow sensor was a flapper/microswitch combination that only measured a discrete threshold for flow.nbsp; The proposed innovation allows for continuous air flow measurement from 1 to 8 acfm with static pressures of 3.5 to 25 psia in the pure oxygen environment.nbsp; This new method meets the low pressure drop requirement and allows operation beyond low earth orbit (LEO) with radiation hardened electronics.nbsp; An engineering demonstration unit (EDU) will be developed during Phase II.