Proficiency Testing for Evaluating Aerospace Materials Test Anomalies

Hirsch, D
Aerospace Engineering Manager, Honeywell Technology Solutions Inc., NASA Johnson Space Center White Sands Test Facility, P.O. Box 20, Las Cruces, NM, 88004

Motto, S
Test Engineer, Honeywell Technology Solutions Inc., NASA Johnson Space Center White Sands Test Facility, P.O. Box 20, Las Cruces, NM, 88004

Peyton, G
Materials and Test Coordinator, P.O. Box 20, Las Cruces, NM, 88004

Beeson, H
NASA Laboratories Office Deputy Chief, NASA Johnson Space Center White Sands Test Facility, P.O. Box 20, Las Cruces, NM, 88004

(Received 14 October 2005; accepted 30 January 2006)
JOURNAL JAI
Abstract

ASTM G 86 “Standard Test Method for Determining Ignition Sensitivity of Materials to Mechanical Impact in Ambient Pressure Liquid Oxygen and Pressurized Liquid and Gaseous Oxygen” and ASTM G 74 “Standard Test Method for Ignition Sensitivity of Materials to Gaseous Fluid Impact” are commonly used to evaluate materials susceptibility to ignition in liquid and gaseous oxygen systems. However, the methods have been known for their lack of repeatability. The inherent problems identified with the test logic would either not allow precise identification or the magnitude of problems related to running the tests, such as lack of consistency of systems performance, lack of adherence to procedures, etc. Excessive variability leads to increasing instances of accepting the null hypothesis erroneously, and so to the false logical deduction that problems are nonexistent when they really do exist. This paper attempts to develop and recommend an approach that could lead to increased accuracy in problem diagnostics by using the 50 % reactivity point, which has been shown to be more repeatable. The initial tests conducted indicate that PTFE and Viton® A

Viton® is a registered trademark of Dupont Dow Elastoncers, Wilmington De.

ASTM International is a member of CrossRef.
Author Hirsch, D Affiliation Aerospace Engineering Manager, Honeywell Technology Solutions Inc., NASA Johnson Space Center White Sands Test Facility, P.O. Box 20, Las Cruces, NM, 88004 Author Motto, S Affiliation Test Engineer, Honeywell Technology Solutions Inc., NASA Johnson Space Center White Sands Test Facility, P.O. Box 20, Las Cruces, NM, 88004 Author Peyton, G Affiliation Materials and Test Coordinator, P.O. Box 20, Las Cruces, NM, 88004 Author Beeson, H Affiliation NASA Laboratories Office Deputy Chief, NASA Johnson Space Center White Sands Test Facility, P.O. Box 20, Las Cruces, NM, 88004 Title: Proficiency Testing for Evaluating Aerospace Materials Test Anomalies Symposium: Flammability and Sensitivity of Materials in Oxygen-Enriched Atmospheres, 2006-10-20
Committee: G04 on Compatibility and Sensitivity of Materials in Oxygen Enriched Atmospheres