ASTM_D_1092_-_12.pdf

Designation:D109212Standard Test Method forMeasuring Apparent Viscosity of Lubricating Greases1This standard is issued under the fixed designation D1092;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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope*1.1 This test method covers measurement,in poises,of theapparent viscosity of lubricating greases in the temperaturerange from 54 to 38C(65 to 100F).Measurements arelimited to the range from 25 to 100 000 Pat 0.1 s1and 1 to 100P at 15 000 s1.NOTE1At very low temperatures the shear rate range may be reducedbecause of the great force required to force grease through the smallercapillaries.Precision has not been established below 10 s1.1.2 This standard uses inch-pound units as well as SI(acceptable metric)units.The values stated first are to beregarded as standard.The values given in parentheses are forinformation only.The capillary dimensions in SI units in Fig.A1.1 and Fig.A1.2 are standard.1.3 WARNINGMercury has been designated by manyregulatory agencies as a hazardous material that can causecentral nervous system,kidney and liver damage.Mercury,orits vapor,may be hazardous to health and corrosive tomaterials.Caution should be taken when handling mercury andmercury containing products.See the applicable product Ma-terial Safety Data Sheet(MSDS)for details and EPAswebsitehttp:/www.epa.gov/mercury/faq.htmfor addi-tional information.Users should be aware that selling mercuryand/or mercury containing products into your state or countrymay be prohibited by law.1.3.1 In addition,temperature measuring devices such asliquid-in-glass thermometers,thermocouples,thermistors,orplatinum resistance thermometers that provide equivalent orbetter accuracy and precision,that cover the temperature rangefor ASTM thermometer 49C,may be used.1.4 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.Referenced Documents2.1 ASTM Standards:2D88 Test Method for Saybolt ViscosityD217 Test Methods for Cone Penetration of LubricatingGreaseD3244 Practice for Utilization of Test Data to DetermineConformance with Specifications3.Terminology3.1 Definitions:3.1.1 apparent viscosity,nof a lubricating grease is theratio of shear stress to shear rate calculated from Poiseuillesequation,and is measured in poises(see 10.1).3.1.2 capillary,nFor the purpose of this test method,acapillary is any right cylindrical tube having a length todiameter ratio of 40 to 1.3.1.3 shear rate,nthe rate at which a series of adjacentlayers of grease move with respect to each other;proportionalto the linear velocity of flow divided by the capillary radius,and is thus expressed as reciprocal seconds.4.Summary of Test Method4.1 The sample is forced through a capillary by means of afloating piston actuated by the hydraulic system.From thepredetermined flow rate and the force developed in the system,the apparent viscosity is calculated by means of Poiseuillesequation.A series of eight capillaries and two pump speeds areused to determine the apparent viscosity at sixteen shear rates.The results are expressed as a log-log plot of apparent viscosityversus shear rate.5.Significance and Use5.1 Apparent viscosity versus shear rate information can beuseful in predicting pressure drops in grease distributionsystems under steady-state flow conditions at constant tem-perature.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.G0.02 on Consistency and Related Rheological Tests.Current edition approved Dec.1,2012.Published January 2013.Originallyapproved in 1950.Last previous edition approved in 2011 as D109211.DOI:10.1520/D1092-12.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.Apparatus6.1 The assembled pressure viscometer consists of fourmajor divisions,the power system,the hydraulic system,thegrease system(described in the annex and shown in Fig.1),and a bath of optional design.Fig.2 is a photograph of the firstthree divisions as commonly used at room temperature.Thisform of the apparatus can be used with a cylindrical insulatedtank 178 mm(7 in.)in diameter