Designation:C813−90(Reapproved2014)StandardTestMethodforHydrophobicContaminationonGlassbyContactAngleMeasurement1ThisstandardisissuedunderthefixeddesignationC813;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedetectionofhydrophobiccontaminationonglasssurfacesbymeansofcontactanglemeasurements.Whenproperlyconducted,thetestwillenabledetectionoffractionsofmonomolecularlayersofhydrophobicorganiccontaminants.Veryroughorporoussurfacesmaysignificantlydecreasethesensitivityofthetest.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D1193SpecificationforReagentWater3.Terminology3.1Definitions:3.1.1advancingangle—thelargestangleobservablewhenaliquiddropletisincreasedinsize.3.1.2hydrophilic—havingastrongaffinityforwater;wet-table.3.1.2.1Discussion—Hydrophilicsurfacesexhibitzerocon-tactangles.3.1.3hydrophobic—havinglittleaffinityforwater;nonwet-table.3.1.3.1Discussion—Hydrophobicsurfacesexhibitcontactanglesappreciablygreaterthanzero:generallygreaterthan45°fortheadvancingangle.3.1.4recedingangle—thesmallestangleobservablewhenaliquiddropletisdecreasedinsize.3.1.5sessiledrop—adropofliquidsittingontheuppersideofahorizontalsurface.3.1.5.1Discussion—SeeFig.1.4.SummaryofTestMethod4.1Thecontactangletestisperformedbydepositingdropletsofpermanganate-distilledwaterorreagentwaterinaccordancewithSpecificationD1193onthesurfacetobetestedusingamountedhypodermicsyringe,saiddropletsbeingdepositedinsuchaway,asdescribe...
