ASTM_D_7685_-_11.pdf

Designation:D768511Standard Practice forIn-Line,Full Flow,Inductive Sensor for Ferromagnetic andNon-ferromagnetic Wear Debris Determination andDiagnostics for Aero-Derivative and Aircraft Gas TurbineEngine Bearings1This standard is issued under the fixed designation D7685;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONIn-line wear debris sensors have been in operation since the early 1990s.There are now thousandsof these devices operating in a wide variety of machinery applications accruing millions of operationalhours.Wear debris sensors provide early warning for the abnormal conditions that lead to failure.Improved machine reliability is possible due to the enhanced sensor data granularity,which providesbetter diagnostics and prognostics of tribological problems from the initiating event through failure.1.Scope1.1 This practice covers the minimum requirements for anin-line,non-intrusive,through-flow oil debris monitoring sys-tem that monitors ferromagnetic and non-ferromagnetic metal-lic wear debris from both industrial aero-derivative and aircraftgas turbine engine bearings.Gas turbine engines are rotatingmachines fitted with high-speed ball and roller bearings thatcan be the cause of failure modes with high secondary damagepotential.(1)21.2 Metallic wear debris considered in this practice range insize from 120 m(micron)and greater.Metallic wear debrisover 1000 m are sized as over 1000 m.1.3 This practice is suitable for use with the followinglubricants:polyol esters,phosphate esters,petroleum industrialgear oils and petroleum crankcase oils.1.4 This practice is for metallic wear debris detection,notcleanliness.1.5 The values stated in SI units are to be regarded asstandard.The values given in parentheses are provided forinformation only.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Terminology2.1 Definitions of Terms Specific to This Standard:2.1.1 condition monitoring,nfield of technical activity inwhich selected physical parameters associated with an operat-ing machine are periodically or continuously sensed,measuredand recorded for the interim purpose of reducing,analyzing,comparing and displaying the data and information so obtainedand for the ultimate purpose of using interim result to supportdecisions related to the operation and maintenance of themachine.(2)2.1.2 control unit,nelectronic controller assembly,whichprocesses the raw signal from the sensor and extracts informa-tion about the size and type of the metallic debris detected.2.1.2.1 DiscussionA computer(s),accessories,and datalink equipment that an operator uses to control,communicateand receive data and information.2.1.3 full flow sensor,nmonitoring device that installsin-line with the lubrication system and is capable of allowingthe full flow of the lubrication fluid to travel through the sensor.Also referred to as a through-flow sensor.2.1.4 inductive debris sensor,ndevice that creates anelectromagnetic field as a medium to permit the detection andmeasurement of metallic wear debris via permeability forferromagnetic debris and eddy current effects for non-ferromagnetic debris.2.1.4.1 DiscussionA device that detects metallic weardebris that cause fluctuations of the magnetic field.A device1This practice is under the jurisdiction of ASTM Committee D02 on PetroleumProducts,Liquid Fuels,and Lubricants and is the direct responsibility of Subcom-mittee D02.96.07 on Integrated Testers,Instrumentation Techniques for In-ServiceLubricants.Current edition approved Jan.1,2011.Published March 2011.DOI:10.1520/D768511.2The boldface numbers in parentheses refer to a list of references at the end ofthis standard.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 that generates a signal proportional to the size and presence ofmetallic wear debris with respect to time.2.1.5 machinery health,nqualitative expression of theoperational status of a machine sub-component,component orentire machine,used to communicate maintenance and opera-tional recommendations or requirements in order to continueoperation,schedule maintenance or take immediate mainte-nance action.2.1.6 metallic wear debris,nin tribology,metallic par-ticles that have become detached in a wear or erosion process.2.1.7 sensor cable,nspecialized cable that connects thesensor output to the electronic control module.2.1.8 trend analysis,nmonitoring of the level and rate ofchange over operating time of measured parameters.3.Summary of Practice3.1 A full