1、Designation: D8092 17Standard Test Method forField Determination of Kinematic Viscosity Using aMicrochannel Viscometer1This standard is issued under the fixed designation D8092; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear 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.1. Scope1.1 This test method describes a means for measuring thekinematic viscosity of transparent and opaque liquids such
3、asnew and in-service lubricating oils using a miniature micro-channel viscometer at 40 C in the range of 12.9 mm2/s to174 mm2/s1.2 The precision has only been determined for thosematerials and viscosity ranges, as indicated in Section 17 onPrecision and Bias.1.3 This test method is specifically tail
4、ored to obtaining arapid, direct, temperature- stabilized measure of the kinematicviscosity of new and in-service lubricants in the field in real-time without the use of solvents or chemical cleaning agents.The measurement takes place at 40 C and kinematic viscosityis directly obtained. No temperatu
5、re extrapolations or densitycorrections are necessary.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is therespons
6、ibility 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. Some specifichazards statements are given in Section 9 on Hazards.1.6 This international standard was developed in accor-dance with inte
7、rnationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D445
8、 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D2162 Practice for Basic Calibration of Master Viscometersand Viscosity Oil StandardsD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD5854 Practice for Mixing and Handlin
9、g of Liquid Samplesof Petroleum and Petroleum ProductsD6708 Practice for Statistical Assessment and Improvementof Expected Agreement Between Two Test Methods thatPurport to Measure the Same Property of a Material2.2 ISO Standard:3ISO/IEC 17025 General Requirements for the Competenceof Testing and Ca
10、libration Laboratories3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 Hele-Shaw cell, na liquid cell wherein Stokes flowis present between two parallel plates.3.1.1.1 DiscussionThe unbounded microchannel capillaryacts as a Hele-Shaw cell in this test method, which enables asim
11、ple relationship between kinematic viscosity and fluidvelocity to be established.3.1.2 loading funnel, nthe cavity in Fig. 1 that the liquidis placed into upon sample introduction; the sample thentravels out of this funnel and enters the capillary.1This test method is under the jurisdiction of ASTM
12、Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.07.0A on Newtonian Viscosity.Current edition approved May 1, 2017. Published May 2017. DOI: 10.1520/D8092-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orco
13、ntact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.Copyrigh
14、t ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International
15、 Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.1.3 miniature capillary viscometer, na viscometer, asshown in Fig. 1, which utilizes an unbounded microchannelcapillary in order to enable the direct measurement of kine-matic
16、 viscosity.3.1.4 unbounded microchannel capillary, na rectangularchannel, approximately 100 m by 2 mm, which comprises thecapillary for this test method.3.1.4.1 DiscussionThe channel, whose top view can beseen in Fig. 1, is unbounded because it is open to air on twosides. The sample stays in the cap
17、illary and does not leakthrough the unbounded portion due to the inherent surfacetension at the boundary between the capillary and air. Thecapillary is repeatedly assembled for the purpose of theviscosity measurement and then disassembled immediatelyafter the viscosity measurement to allow for clean
18、ing. This isaccomplished by having two mirror sides, which comprise thecapillary, coupled by means of a clamshell arrangement. Theintegrity of the capillary is ensured by spacers which guaranteethe distance between the two mirror sides when closing theclamshell.4. Summary of Test Method4.1 A liquid
19、sample is placed into the loading funnel (seeFig. 1) of the miniature capillary viscometer and kinematicviscosity at 40 C is determined by measuring the time inseconds (t) it takes this liquid to travel between the beamproduced by LED (light-emitting diode) #1 and LED #3.4.2 These times associated w
20、ith the liquid passing eachLED are determined by monitoring the voltage of the corre-sponding photodiodes: The starting time (t=0) is defined aswhen the operator initiates by means of button push the testsequence; a built-in clock then tracks the travel time. When theliquid enters the vicinity of th
21、e LED beam, the time, from thetest starting time, at which the liquid is determined to havepassed this beam is defined as the photodiode voltage falling bya factor of 0.5.4.3 The liquid sample thermalizes rapidly to 40 C as theentire unbounded microchannel capillary is constructed ofaluminum which i
22、s stabilized at 40 C. Thus when the 60 Lliquid is placed into the microchannel capillary it immediatelyFIG. 1 Miniature Capillary Viscometer SchematicD8092 172comes into contact with the aluminum and the liquid flowingout of the loading funnel thermalizes to 40 C within tenths ofseconds.4.4 The kine
23、matic viscosity in square millimetres persecond (mm2/s) is determined a linear relationship with t, thatis, 5n1t1n2. The slope (n1)inmm2/s2and offset (n2)inmm2/s of this linear relationship are determined by calibrationat the factory or at the point of use using certified viscosityreference standard
24、s.5. Significance and Use5.1 The significance of this test method is that it provides ameans for a reliable field determination of kinematic viscosityat 40 C without requiring solvents or chemicals for cleaning.Field use implies that the fluid may be very opaque, such as anin-service engine oil. The
25、 device may be cleaned with adisposable lint-free oil-absorbent material such as a cleancotton shop rag, and requires only 60 L of sample foroperation. As such the device provides a unique service to arange of industries where it is difficult or undesirable to obtainchemicals of any sort in order to
26、 determine the kinematicviscosity of their fluid of interest. Examples of such industriesinclude many marine-based systems where a laboratory doesnot exist on-board, mines where equipment is needed foron-the-spot determination of asset viscosity, and large indus-trial plants where a walk-around insp
27、ection of oil sumpsgreatly increases efficiency. By using this test method, one canserve these crucial use-cases where a direct, immediate mea-sure of kinematic viscosity at 40 C may otherwise be difficultto obtain.6. Interferences6.1 Possible interferences for this test method include thepresence o
28、f large particles in the liquid which would tend to getstuck in the capillary and impede the liquid flow. Since thecapillary is only approximately 100 m in its smallest dimen-sion this must be carefully considered. To address this in thefield, a middle LED/photodiode arrangement (#2, see Fig. 1)vali
29、dates the linearity of the flow. If the flow is found to benon-linear, the operator is instructed that a probable invalidmeasurement has occurred and a re-test is indicated. Thisre-test involves cleaning the capillary and thereby removingany trapped particulate. If the liquid being analyzed commonly
30、has a large population of particulate expected in the 60 L ofdrawn sample, letting the sample settle and sampling towardsthe top of a bottle as described in Practice D4057 may befollowed in order to significantly reduce the probability thatthis occurs.7. Apparatus47.1 The miniature capillary viscome
31、ter (see Fig. 1) consistsof the following components:7.1.1 Temperature-controlled aluminum plates coupled to-gether in a clamshell arrangement. These plates serve as a heatsink for bringing the liquid to a fixed temperature rapidly uponthe sample being loaded into the device.7.1.2 Temperature contro
32、l of the aluminum plates is accom-plished using a built-in PID controller with insulated stripheaters placed on the back side of each plate. Two PID(proportional integral derivative) loops control each plateseparately. The thermistor is also placed into each plate, on theback side but as near as pos
33、sible to the center of the liquid flowthrough the capillary. Such an arrangement controls tempera-ture of the liquid to within 0.1 C.7.1.3 An unbounded microchannel capillary is machinedinto the temperature-controlled aluminum plates in the centerof the two plates.7.1.4 Miniature emitters operating
34、at a center wavelength of880 nm are used for the LEDs. Center wavelength 850 nmsilicon photodiodes are used for detecting the LED illumina-tion. Using a real-time operating system, the voltage on thesephotodiodes is monitored at millisecond resolution and is useddetermine the time, relative to when
35、the test is initiated, whenthe liquid has passed the threshold of each LED beam. Thistime detection system is mounted in a measurement chamberwhich receives the aluminum plates. This measurement cham-ber uses a permanent-magnet holder to ensure the alignmentbetween the aluminum plates (which contain
36、 the capillary) andthe time detection system.7.1.5 The viscometer control system comprises embeddedelectronics which allow the user to control the system andperform the viscosity measurement.7.1.6 A micropastuerette, or micropipette with disposabletip, is used to dispense 60 L of fluid into the load
37、ing funnel.8. Reagents and Materials8.1 Reagent grade chemicals shall be used in all tests.Unless otherwise indicated, it is intended that all reagents shallconform to the specifications of the committee on AnalyticalReagents of the American Chemical Society, where suchspecifications are available.5
38、Other grades may be used, pro-vided it is pure enough to be used without lessening theaccuracy of the determination.8.2 Certified Viscosity Reference StandardsThese are foruse as confirmatory checks on the procedure in the laboratory.Certified viscosity reference standards shall be certified by alab
39、oratory, which has shown to meet the requirements ofISO/IEC 17025 or a corresponding national standard byindependent assessment. Viscosity standards shall be traceableto master viscometer procedures described in Test MethodD2162. The accepted reference value for the Certified Refer-ence Material mus
40、t be known with a relative error no greaterthan 0.25 % with a 95 % confidence.4The sole source of supply of the apparatus known to the committee at this timeis Spectro Scientific, Inc., Chelmsford, MA, USA. These viscometers are coveredunder US Parents 8,661,878, 9,234,829, and related international
41、 patents and filings.If you are aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.5Reagent Chemicals, American Chemical Society S
42、pecifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Co
43、nvention, Inc. (USPC), Rockville,MD.D8092 1738.3 A microdispenser (such as a pastuerette) which canaccurately (within 610 L) dispense 60 L of sample liquid isrequired.8.4 A lint free, oil-absorbent material should be used toclean the viscometer. Some suitable examples would be poly-propylene industr
44、ial wipes or a clean cotton shop rag.9. Hazards9.1 The device may utilize a certified Li-Ion battery.9.2 Since the viscometer employs metal plates heated to40 C which come into contact with the operator when wipingclean the viscometer, the PID control is designed so that underno circumstances does t
45、he temperature of the plates reachelevated temperatures which may be hazardous to the humantouch.10. Sampling, Test Specimens, and Test Units10.1 A sample of the liquid should be obtained. At mini-mum a quantity of 60 L is needed. If obtained directly fromthe equipment such as with a dipstick or fro
46、m a bottle thatcontains a recent sample, the sample should be representativeof the system and no further actions are required. The sampleshould be at temperatures that are compatible with the speci-fications of the microdispenser used when drawn for analysis.If such equipment is available, the sampl
47、e may be obtained asdescribed in Practice D4057.10.2 If the sample is obtained from a source, such as ananalysis bottle, that may be non-homogeneous, or clearlyappears to be non-homogeneous, the sample should be re-homogenized to ensure that a representative sample will beobtained. Follow Practice D
48、5854 and ensure that the sample isgently inverted 20 times before drawing a sample in thesecases.11. Preparation of Apparatus11.1 Ensure that the viscometer resides upright on a flat,hard surface.11.2 The microchannel is cleaned with a lint free, oil-absorbent material by wiping it along the capilla
49、ry flow area,from the center of the Hele-Shaw cell towards the loadingfunnel, removing liquid and debris.11.3 The microchannel is cleaned again with a lint free,oil-absorbent material by pressing it firmly on the capillaryflow area and rubbing it for at least five (5) strokes, or until novisible sample residue remains.11.4 Make a final cleaning stroke using the lint free,oil-absorbent material along both capillary flow areas on eachhalf of the Hele-Shaw cell.11.5 Inspect the aluminum plates and in particular theunbounded microchannel capillary area
