High-Accuracy Oxygen Flow Meter for the Exploration Portable Life Support System

Date

2020-07-31

Journal Title

Journal ISSN

Volume Title

Publisher

2020 International Conference on Environmental Systems

Abstract

"The xEMU’s portable life support system (xPLSS) requires a high accuracy instrument to measure the rate of oxygen flow in the ventilation system. The sensor must produce accurate readings across a wide range of flow conditions while consuming very little volume or power and introducing very little pressure loss to the ventilation loop.

We have developed an innovative flow sensor built around a commercial, off-the-shelf MEMS flow-sensing chip that is designed for oxygen service. We have developed a custom flow sensor housing to channel gas flow over the MEMS sensing elements and custom electronics to control the sensor and generate signals compatible with xEMU requirements. The flow sensor operates in parallel with the ventilation loop heat exchanger, so introduces no additional pressure loss to the ventilation system. The unit meets size and shape requirements for service in the xPLSS and is replaceable in space if necessary.

Data from separate-effects tests and tests of the integrated xPLSS heat exchanger / flow meter system show that the flow meter achieves high accuracy requirements across the range of specified operating conditions.

We built and tested a proof-of-feasibility prototype in mid-2019, followed by a “rapid turn” demonstration sensor that meets form, fit and function requirements in late 2019. Fully-qualified DVT units are scheduled for delivery in mid-2020."

Description

Michael Izenson, Creare LLC, US
Amelia Servi, Creare LLC, US
Sheldon Stokes, Creare LLC, US
Theodore Beach, Creare LLC, US
Carl Kirkconnell, West Coast Solutions, US
Leon Huynh, West Coast Solutions, US
Tessa Rundle, National Aeronautics and Space Administration (NASA) Lyndon B. Johnson Space Center, US
Steven Lee, Renesas, US
ICES402: Extravehicular Activity: PLSS Systems
The proceedings for the 2020 International Conference on Environmental Systems were published from July 31, 2020. The technical papers were not presented in person due to the inability to hold the event as scheduled in Lisbon, Portugal because of the COVID-19 global pandemic.

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Rights Availability

Keywords

Portable life support system, Ventilation loop, Oxygen flow meter

Citation