NASA LogoNTRSNTRS - NASA Technical Reports ServerSearchmore_vertCollectionsAboutNewsHelpLogin Back to ResultsA TEOM (tm) particulate monitor for comet dust, near Earth space, and planetary atmospheresScientific missions to comets, near earth space, and planetary atmospheres require particulate and mass accumulation instrumentation for both scientific and navigation purposes. The Rupprecht & Patashnick tapered element oscillating microbalance can accurately measure both mass flux and mass distribution of particulates over a wide range of particle sizes and loadings. Individual particles of milligram size down to a few picograms can be resolved and counted, and the accumulation of smaller particles or molecular deposition can be accurately measured using the sensors perfected and toughened under this contract. No other sensor has the dynamic range or sensitivity attained by these picogram direct mass measurement sensors. The purpose of this contract was to develop and implement reliable and repeatable manufacturing methods; build and test prototype sensors; and outline a quality control program. A dust 'thrower' was to be designed and built, and used to verify performance. Characterization and improvement of the optical motion detection system and drive feedback circuitry was to be undertaken, with emphasis on reliability, low noise, and low power consumption. All the goals of the contract were met or exceeded. An automated glass puller was built and used to make repeatable tapered elements. Materials and assembly methods were standardized, and controllers and calibrated fixtures were developed and used in all phases of preparing, coating and assembling the sensors. Quality control and reliability resulted from the use of calibrated manufacturing equipment with measurable working parameters. Thermal and vibration testing of completed prototypes showed low temperature sensitivity and high vibration tolerance. An electrostatic dust thrower was used in vacuum to throw particles from 2 x 10(exp 6) g to 7 x 10(exp -12) g in size. Using long averaging times, particles as small as 0.7 to 4 x 10(exp 11) g were weighted to resolutions in the 5 to 9 x 10(exp -13) g range. The drive circuit and optics systems were developed beyond what was anticipated in the contract, and are now virtually flight prototypes. There is already commercial interest in the developed capability of measuring picogram mass losses and gains. One area is contamination and outgassing research, both measuring picogram losses from samples and collecting products of outgassing.Document ID19930006501Acquisition SourceLegacy CDMSDocument TypeContractor Report (CR)Date AcquiredSeptember 6, 2013Publication DateApril 1, 1988Subject CategoryAstrophysicsReport/Patent NumberNASA-CR-190868NAS 1.26:190868Accession Number93N15690Funding Number(s)CONTRACT_GRANT: NAS7-962CONTRACT_GRANT: SBIR-08.03-4520Distribution LimitsPublicCopyrightWork of the US Gov. Public Use Permitted.Available DownloadsNameType19930006501.pdfSTIcloud_downloadcontent_copyvisibilityRelated RecordsThere are no records associated with this record.visibility_offNo Preview Available
 No Fear Act | Freedom of Information Act | Office of the Inspector General | Agency Financial ReportsNASA Web Privacy Policy and Important Notices | NASA Guidelines for Quality of InformationDisclaimers, Copyright, Terms of Use | Accessibility | NASA OCIO | USA.gov | NASA.govContact Us | Site MapSTI LogoNASA Official: JoAnne R. Calhoun Site Curator: STI Compliance and Distribution Services Last Modified: September 12, 2024