Accession Number : ADA337597

Title :   COBRA II Correlation Study & Field Performance Summary

Descriptive Note : Final rept. Jul-Oct 97

Corporate Author : WRIGHT LAB WRIGHT-PATTERSON AFB OH AERO PROPULSION AND POWER DIRECTORATE

Personal Author(s) : Wright, Robert, Jr

PDF Url : ADA337597

Report Date : NOV 1997

Pagination or Media Count : 34

Abstract : A correlation study of the complete oil breakdown rate analyzer, version II (COBRA II) was undertaken to determine the approximate repeatability and reproducibility of data from these oil analysis instruments. Simple root mean square (RMS) equations were used to calculate these parameters. The COBRA II monitors the level of thermal degradation in synthetic, ester-based turbine engine oils. The 95% confidence levels for repeatability and reproducibility were less than 5% and 12% RMS, respectively. The performance of the COBRA II was found to be acceptable and very similar to the repeatability and reproducibility of data from typical Joint Oil Analysis Program (JOAP) atomic emission spectrometers. Additionally, a summary of the field performance to date of the COBRA II is included. The COBRA II has helped to save at least 13 US Air Force turbine engines from oil system (bearing) failure, amounting to savings of about $39M and a 17,000% return on investment. COBRA II appears to be a very good analytical tool for use in turbine engine maintenance programs where significant oil thermal degradation problems may exist.

Descriptors :   *LUBRICATING OILS, MAINTENANCE, MONITORING, LEAST SQUARES METHOD, TURBINES, CORRELATION TECHNIQUES, REPRODUCIBILITY, THERMAL DEGRADATION.

Subject Categories : Lubricants and Hydraulic Fluids

Distribution Statement : APPROVED FOR PUBLIC RELEASE