1、Designation:D 5180 93(Reapproved 1998)Standard Test Method forQuantitative Test for Turbidity in Clear Liquids1This standard is issued under the fixed designation D 5180;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of las
2、t revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the measurement of turbidity ofclear liquids.It is applicable to resin solutions,solvents,clearcoatin
3、gs,monomers,and any other liquids where clarity isspecified.This test method should be used only for comparisonof clarity of similar materials,and not to obtain absolute valuesfor turbidity.1.2 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is t
4、heresponsibility 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:D 1889 Test Methods for Turbidity of Water2D 2090 Test Method for Clarity and Cleanline
5、ss of Paintand Ink Liquids3E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method43.Summary of Test Method3.1 A specimen is placed in a vial and measured on a ratiorecording turbidimeter.The instrument is calibrated innephelometric turbidity units(NTU),with
6、 standards providedby the manufacturer.Turbidity of the specimen is read directlyin NTUs.The instrumental values are insensitive to color andrequire no color correction.4.Significance and Use4.1 This test method is applicable to resin solutions,sol-vents,clear coatings,monomers,and any other liquid
7、whereclarity is specified.It is designed to provide an objective,instrumental method that is repeatable and reproducible.NOTE1The only other ASTM test method for determining clarity ofresin solutions is Test Method D 2090.Test Method D 2090 determinesclarity by visual inspection versus the instrumen
8、tal determination in thistest method.5.Apparatus5.1 Ratio Recording TurbidimeterSupplier and consumershould agree on a common instrument,since optics varybetween instrument companies and that will effect results.5.2 Cylindrical Glass Vials with Screw Caps,30 mL,25 mmoutside diameter by 95 mm high.Fo
9、r very low values,followinstrument manufacturers recommendation.NOTE2Inexpensive vials,available from most scientific supplycompanies,are adequate for most paint materials.However,minorvariations in clarity and thickness of the glass may be significant whenmeasuring specimens with very low turbidity
10、.For values of less than 5NTU,use only manufacturers specified vials.5.3 Secondary StandardsSee Test Methods D 1889 forprocedure to calibrate secondary standards.6.Procedure6.1 Allow instrument to warm for at least 10 min beforeusing.6.2 Using the standards supplied with instrument,calibrateat least
11、 once a month,as directed in the instrument manual.6.3 Before each use,check the instrument with the second-ary standard supplied by the instrument supplier.If instrumentis outside the manufacturers specified range,recalibrate.6.4 Carefully fill a clean,dry vial to within a centimetre ofthe top and
12、cap tightly.Pour down the side of the vial,tominimize bubble formation.If bubbles are observed,allowthem to dissipate before making the measurement.In mostcases,bubbles may be removed rapidly by use of a sonic bath,centrifuging,or pulling a slight vacuum.Wipe off any lint orsmudge from the outside s
13、urface before making the measure-ment.NOTE3Bubbles will produce erroneously high results.6.5 Place the vial in the instrument and record the reading.Use the lowest range setting possible.Measure at least twospecimens in separate vials.NOTE4Specimens that settle rapidly may decrease during measure-me
14、nt.If that happens,record the highest value observed.1This test method is under the jurisdiction of ASTM Committee D-1 on Paintsand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.33 on Polymers and Resins.Current edition approved May 15,1993.Published
15、 July 1993.Originallypublished as D 5180 92.Last previous edition D 5180 92.2Annual Book of ASTM Standards,Vol 11.01.3Annual Book of ASTM Standards,Vol 06.03.4Annual Book of ASTM Standards,Vol 14.02.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,Unite
16、d States.7.Report7.1 Report the average of two results obtained in separatevials.8.Precision and Bias8.1 PrecisionThe precision of this test method as deter-mined by the statistical examination of the interlaboratory testresults(see Practice E 691),is as follows:8.1.1 RepeatabilityThe difference between duplicate re-sults by the same operator with the same apparatus on identicaltest material would,in the normal and correct operation of thistest method,exceed the following values less than 1%of t