A report discusses the second generation of the JPL Electronic Nose (ENose), an array of 32 semi-specific chemical sensors used as an event monitor to identify and quantify contaminants released into breathing air by leaks or spills. It is designed to monitor the environment for changes in air quality, and is trained to identify and quantify selected chemical species at predetermined concentrations, ranging from sub-ppm to ppth. This system has improved reproducibility for making matched arrays, allowing use of data analysis software with minimal recalibration on sensor set replacement. The Second Generation (SG) ENose is a follow- up to the first JPL Electronic Nose that was tested on an earlier space shuttle mission (STS-95). Improvements have been made to the hardware, sensor materials, and data analysis software.
The SG ENose can be adapted to different applications and analyte sets by selection of sensor sets. A monolithic chassis eliminates most fittings, tubing, and dead space, improving the flow system. The SG ENose also includes humidity and temperature sensors in the sensing chamber for improved event deconvolution. The design allows simple and rapid change-out of sensor sets and of filter material. All surfaces exposed to analyte are made of inert materials, and the unit is small enough to be handheld.
This work was done by Margie Homer, Shiao-Pin Yen, Margaret Ryan, Abhijit Shevade, Hanying Zhou, Adam Kisor, Darrell Jan, April Jewell, Charles Taylor, Allison Manfreda, and Kenneth Manatt of Caltech for NASA’s Jet Propulsion Laboratory. For more information, download the Technical Support Package (free white paper) at www.techbriefs.com/tsp under the Physical Sciences category. In accordance with Public Law 96-517, the contractor has elected to retain title to this invention. Inquiries concerning rights for its commercial use should be addressed to:
Innovative Technology Assets Management
JPL
Mail Stop 202-233
4800 Oak Grove Drive
Pasadena, CA 91109-8099
(818) 354-2240
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Refer to NPO-43051, volume and number of this NASA Tech Briefs issue, and the page number.
This Brief includes a Technical Support Package (TSP).
Second-Generation Electronic Nose
(reference NPO-43051) is currently available for download from the TSP library.
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Overview
The document is a Technical Support Package for the Second-Generation Electronic Nose (Enose) developed by NASA's Jet Propulsion Laboratory (JPL). It outlines the advancements and functionalities of the Enose, which is designed for monitoring air quality, particularly in environments such as spacecraft and habitats where human life is supported.
The Enose has undergone significant development, expanding its analyte detection capabilities from 10 to 22 different chemical species. It incorporates advanced data analysis techniques, including quasi real-time data processing, humidity subtraction to detect low concentrations of analytes, and temperature effect investigations. These enhancements aim to improve the accuracy and reliability of gas detection, which is crucial for maintaining safe air quality.
The document details the operational functions of the Enose, which include monitoring for targeted contaminants, identifying and quantifying chemical species associated with fires or overheating electronics, and overseeing clean-up processes. The device is characterized by its low mass and power requirements, making it suitable for use in constrained environments. It is designed to require minimal crew time for maintenance and calibration, which is essential for long-duration missions.
The data analysis approach is outlined in a flow chart, illustrating the steps from reading raw data to preprocessing, identifying functional groups, and reporting results. The Enose employs calibration and sensor selection processes to ensure accurate detection and classification of gases. The document emphasizes that while much of the model building is developed, there is still a need for improvements and modifications to accommodate new sensors and analytes.
Overall, the Technical Support Package serves as a comprehensive overview of the JPL Enose program, highlighting its capabilities, development history, and the methodologies employed in data analysis and sensor technology. It reflects NASA's commitment to advancing technologies that have broader applications beyond aerospace, contributing to environmental monitoring and safety in various fields. For further inquiries or information, the document provides contact details for the Innovative Technology Assets Management at JPL.
