1、Designation:D154513Standard Test Method forViscosity of Transparent Liquids by Bubble Time Method1This standard is issued under the fixed designation D1545;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A n
2、umber 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.Scope1.1 This test method covers the determination of the viscos-ity
3、 in bubble seconds by timing.The bubble seconds areapproximately equal to stokes for most liquids.1.2 The test method is applicable to transparent liquids thatare free from crystalline or gel particles.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are
4、included in thisstandard.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
5、to use.2.Terminology2.1 Definitions:2.1.1 viscosity,nthe resistance experienced by one portionof a liquid moving over another portion of the liquid.Theabsolute unit of viscosity in the cgs,centimeter-gram-second,system is the poise which is expressed as dyne-seconds persquare centimetre.Stokes are e
6、qual to poises divided bydensity.The absolute SI,International System of Units(metricsystem),viscosity unit is the pascal-second.3.Apparatus3.1 Constant-Temperature BathAny suitable bath capableof maintaining temperature at 25 6 0.1C with water as thebath medium.3.2 Standard Viscosity Tubes of clear
7、 glass and with flatbottoms,10.65 6 0.025 mm in inside diameter;114 6 1 mmin outside length.Plainly legible lines shall be located asfollows(Note 1):27 6 0.5 mm100 6 0.5 mm108 6 0.5 mmThe distance between the first and second lines shall be 73 60.5 mm.NOTE1All distances shall be measured from the ou
8、tside bottom of thetube.3.3 Reference StandardsA series of standard viscositytubes(3.2)filled with transparent liquids having predeterminedviscosities in centistokes and bubble seconds as listed in Table1.The standards are listed alphabetically from the lowestviscosity to the highest viscosity stand
9、ard.3.4 Timing DeviceStopwatch or electric stop clock ca-pable of being read to a precision of 0.1 s.3.5 Tube Racks,capable of inverting one or more viscositytubes 180 to within 1 of a vertical position while rack andtubes are immersed in the constant temperature bath.3.6 Viscosity Tube Corks,No.2 s
10、hort.4.Procedure4.1 Fill a standard viscosity tube with the material to betested to approximately level with the 108-mm line.4.2 Transfer the tube to a constant 25C temperature bathwith the cork loosely inserted.Hold at this temperature for 10min.NOTE2Adequate control of the temperature bath is esse
11、ntial.Avariation of 0.1C in the temperature of the bath will cause a 1%variationin the timed bubble travel.4.3 At the end of 10 min adjust the level of the liquid so thatthe bottom meniscus will be level with the 100-mm line.Insertthe cork so that the bottom of the cork is on the level with the108-m
12、m line.This will ensure a bubble of suitable and uniformsize.4.4 Insert the tube in the rack and immerse in the 25Cwater bath.Allow the tube(s)to stand with cork down in thebath a minimum of 20 min before determining the viscosity.NOTE3For viscosities of liquids that have a timed bubble travel of 4
13、sor less,more precise results can be obtained by comparison againstreference standards having a predetermined viscosity or timed bubbletravel.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofS
14、ubcommittee D01.24 on Physical Properties of Liquid Paints and Paint Materials.Current edition approved Feb.1,2013.Published March 2013.Originallyapproved in 1958.Last previous edition approved in 2012 as D1545 07(2012).DOI:10.1520/D1545-13.Copyright ASTM International,100 Barr Harbor Drive,PO Box C
15、700,West Conshohocken,PA 19428-2959.United States1 4.5 To read,invert the tube quickly and determine the timerequired for the bubble to rise in seconds.When determiningthe time in seconds start the timing device when the top of thebubble becomes tangent to the 27-mm line on the tube.Stopthe timing w
16、hen the top of the bubble becomes tangent with the100-mm line.This gives a 73-mm timed bubble travel.Alltimings shall be made with the tube in an exact verticalposition.NOTE4Positioning of the tube in a vertical position is mandatory.Atube one radius off the vertical will give an error of approximately 10%in the time of bubble travel.5.Report5.1 Report the following information:5.1.1 The viscosity obtained by the timing method ex-pressed as“bubble seconds”or“approximate stokes.”NOTE5The time in
