ASTM_D_938_-_12.pdf

Designation:D93812British Standard 5088Designation:76/70(95)Standard Test Method forCongealing Point of Petroleum Waxes,IncludingPetrolatum1This standard is issued under the fixed designation D938;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 Department of Defense.1.Scope*1.1 This test method covers determination of the congealingpoint of petroleum waxes,including petrolatum.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.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.1.4 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.NOTE1This test method is an alternative to Test Method D127.Results obtained are usually lower than the results obtained by TestMethod D127 IP 133,the amount of the deviation varying with thenature of the petroleum wax.2.Referenced Documents2.1 ASTM Standards:2D127 Test Method for Drop Melting Point of PetroleumWax,Including PetrolatumE1 Specification for ASTM Liquid-in-Glass Thermometers3.Terminology3.1 Definitions:3.1.1 congealing point,nof petroleum wax,that tempera-ture at which molten petroleum wax,when allowed to coolunder prescribed conditions,ceases to flow.3.1.2 thermometer,na device for determining temperatureusing one of a variety of different principles.3.1.2.1 DiscussionA thermometer has two important ele-ments:the temperature sensor,within which some physicalchange occurs with temperature(for example,the bulb of aliquid-in-glass thermometer,or a thermistor in an electronicthermometer),plus some means of converting this change intoa numerical value(for example,the scale on a liquid-in-glassthermometer,or a digital readout in the case of an electronicthermometer).4.Summary of Test Method4.1 A sample of wax is melted and a droplet is made toadhere to the bulb of a thermometer.Using a prewarmed flaskas an air jacket,the droplet on the bulb is allowed to cool at afixed rate until it congeals.The congealing point is observed asthe temperature at which the droplet ceases to flow as thethermometer is turned.5.Significance and Use5.1 Congealing point is a wax property that is of interest tomany petroleum wax consumers.The procedure described heremeasures the temperature at which a sample being cooleddevelops a“set”or resistance to flow.At that temperature,thewax may be at or close to the solid state,or it may be semisolidand quite unctuous,depending on the composition of the waxor petrolatum being tested.In the case of petrolatums,congeal-ing property is associated with the formation of a gel structureas the sample cools.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.10.0A on Physical/Chemical Properties.Current edition approved Dec.1,2012.Published February 2013.Originallyapproved in 1947.Last previous edition approved in 2005 as D93805.DOI:10.1520/D0938-12.2For 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 Thermometer,covering the range of 20 to 100C(68 to213F).6.1.1 If used,mercury-in-glass thermometers shall conformto the requirements prescribed in Specification E1 or in thespecifications for IP Standard Thermometers:ThermometerNumberTemperature RangeASTMIP20 to 100C54C18C68 to 213F54F18F6.1.2 Thermometric devices such as RTDs,thermistors,orother liquid-in-glass thermometers of equal or better accuracy,and covering the appropriate temperature range,may be used.6.2 Erlenmeyer Flask,125-mL,glass,to serve as a ther-mometer jacket.6.3 Cork or Rubber Stopper,for attaching the thermometerto the Erle