ASTM D1092-2012 Standard Test Method for Measuring Apparent Viscosity of Lubricating Greases《润滑脂表观粘度测量的标准试验方法》.pdf

1、Designation:D109211D109212 Standard Test Method for Measuring Apparent Viscosity of Lubricating Greases 1 This standard is issued under the xed designation D1092; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last re

2、vision.Anumber in parentheses indicates the year of last reapproval.A superscript 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 Scope* 1.1 This test method covers measurement,

3、 in poises, of the apparent viscosity of lubricating greases in the temperature range from 54 to 38C (65 to 100F). Measurements are limited to the range from 25 to 100000 Pat 0.1 s 1 and 1 to 100 Pat 15000 s 1 . NOTE 1At very low temperatures the shear rate range may be reduced because of the great

4、force required to force grease through the smaller capillaries. Precision has not been established below 10 s 1 . 1.2 This standard uses inch-pound units as well as SI (acceptable metric) units. The values stated rst are to be regarded as standard.Thevaluesgiveninparenthesesareforinformationonly.The

5、capillarydimensionsinSIunitsinFig.A1.1andFig.A1.2 are standard. 1.3 WARNINGMercury has been designated by many regulatory agencies as a hazardous material that can cause central nervous system, kidney and liver damage. Mercury, or its vapor, may be hazardous to health and corrosive to materials. Cau

6、tion should be taken when handling mercury and mercury containing products. See the applicable product Material Safety Data Sheet (MSDS) for details and EPAs websitehttp:/www.epa.gov/mercury/faq.htmfor additional information. Users should be aware that selling mercury and/or mercury containing produ

7、cts into your state or country may be prohibited by law. 1.3.1 Inaddition,temperaturemeasuringdevicessuchasliquid-in-glassthermometers,thermocouples,thermistors,orplatinum resistance thermometers that provide equivalent or better accuracy and precision, that cover the temperature range for ASTM ther

8、mometer 49C, may be used. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations pr

9、ior to use. 2. Referenced Documents 2.1 ASTM Standards: 2 D88Test Method for Saybolt Viscosity D217Test Methods for Cone Penetration of Lubricating Grease D3244Practice for Utilization of Test Data to Determine Conformance with Specications 3. Terminology 3.1 Denitions: 3.1.1 apparentviscosity,nofal

10、ubricatinggreaseistheratioofshearstresstoshearratecalculatedfromPoiseuillesequation, and is measured in poises (see 10.1). 3.1.2 capillary, nForthepurposeofthistestmethod,acapillaryisanyrightcylindricaltubehavingalengthtodiameterratio of 40 to 1. 3.1.3 shear rate, nthe rate at which a series of adja

11、cent layers of grease move with respect to each other; proportional to the linear velocity of ow divided by the capillary radius, and is thus expressed as reciprocal seconds. 1 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products and Lubricants and is the direct resp

12、onsibility of Subcommittee D02.G0.02 on Consistency and Related Rheological Tests. Current edition approved Sept. 1, 2011Dec. 1, 2012. Published September 2011January 2013. Originally approved in 1950. Last previous edition approved in 20052011 as D109205.11. DOI: 10.1520/D1092-11.10.1520/D1092-12.

13、2 ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatserviceastm.org.ForAnnualBookofASTMStandards volume information, refer to the standards Document Summary page on the ASTM website. This document is not anASTM standard and is intended only to provide the user

14、 of anASTM standard an indication of what changes have been made to the previous version. Because it may not be technically possible to adequately depict all changes accurately,ASTM recommends that users consult prior editions as appropriate. In all cases only the current version of the standard as

15、published by ASTM is to be considered the official document. *ASummary of Changes section appears at the end of this standard Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States 14. Summary of Test Method 4.1 The sample is forced through

16、a capillary by means of a oating piston actuated by the hydraulic system. From the predetermined ow rate and the force developed in the system, the apparent viscosity is calculated by means of Poiseuilles equation.Aseriesofeightcapillariesandtwopumpspeedsareusedtodeterminetheapparentviscosityatsixte

17、enshearrates.The results are expressed as a log-log plot of apparent viscosity versus shear rate. 5. Signicance and Use 5.1 Apparent viscosity versus shear rate information can be useful in predicting pressure drops in grease distribution systems under steady-state ow conditions at constant temperat

18、ure. 6. Apparatus 6.1 The assembled pressure viscometer consists of four major divisions, the power system, the hydraulic system, the grease system(describedintheannexandshowninFig.1),andabathofoptionaldesign.Fig.2isaphotographoftherstthreedivisions as commonly used at room temperature. This form of

19、 the apparatus can be used with a cylindrical insulated tank 178 mm (7 in.) in diameter and 508 mm (20 in.) deep.The bath medium may be kerosene or alcohol cooled manually with dry ice.Alternatively the grease system, the grease and hydraulic system, or all three major divisions can be built into an

20、y liquid or air bath that will cover the temperature range and maintain the grease at test temperature 60.25 C (60.5F). 7. Sampling 7.1 A single lling of the grease cylinder requires about 0.223 kg ( 1 2 lb) of grease which is the minimum size sample. NOTE 2It is possible for an experienced operator

21、 to complete the 16 single determinations with a single lling. However, some samples reach the equilibrium pressure slowly, making it advisable to have a sample of several pounds available. 7.2 Generally no special preparation of the sample is necessary. NOTE 3The apparatus works the samples to some

22、 extent as they pass through the capillary. Somewhat better precision is obtained if they are previously worked as described in Test Methods D217. Working of some greases may cause aeration. NOTE 4It is desirable to lter some greases through a 60-mesh screen to prevent plugging the No. 8 capillary.

23、Follow prudent laboratory practice to keep equipment cleaned and ushed before use. 8. Calibration and Standardization 8.1 To calibrate the hydraulic system, remove the grease cylinder and replace it with a needle valve. Select a hydraulic oil of about 2000 cSt (2000 mm 2 /s) viscosity at the test te

24、mperature. Fill the system with hydraulic oil and circulate the oil until it is free of air bubbles.At atmospheric pressure, quickly place a 60-mL Saybolt receiving ask (Test Method D88), under the outlet and start a timer. Determine the delivery time for 60 mL and calculate the ow rate in cubic cen

25、timetres per second assuming 1 FIG. 1 Schematic Drawing of Apparatus D109212 2mLequal to 1 cm 3 . Repeat this observation at 500, 1000, 1500 psi (3.45, 6.89, 10.4 MPa) and at sufficient pressures above 1500 psitodevelopacalibrationcurveofthetypeasshowninFig.3.Thedevelopedcurveofthetypeisusedtocorrec

26、towrateswhen grease is dispensed. Repeat the calibration at intervals to determine if wear is changing the pump ow. 8.2 Analternativeprocedureforthecalibrationofthehydraulicsystemisthemeasurementoftherateofowofthetestgrease. To cover the desired range of shear rates, ow rates over an approximate ran

27、ge of pressure are determined. Any suitable means of measuring the rate of grease ow may be used. 9. Procedure 9.1 Charge the sample so as to reduce inclusion of air to a minimum. Soft greases may be poured into the cylinder or drawn upbyvacuum;heavysamplesmustbehandpacked.Whenllingthecylinderbyvacu

28、um,removethecapillaryendcapandplace the piston ush with the open end and then insert into the sample. Apply vacuum to the opposite end of the cylinder until the cylinder is fully charged with grease.This must be facilitated by tapping with a wooden block. Replace the capillary end cap and ll the upp

29、er end of the cylinder above the piston with hydraulic oil. 9.2 Fill the entire hydraulic system with hydraulic oil. Disconnect, invert and ll the gage and gage connections with oil.With the entire hydraulic system connected and completely lled with oil, adjust the temperature of the sample to the t

30、est temperature 60.25C (60.5F) as determined by a thermocouple inserted in the capillary end cap. Operate the pump until oil ows from the FIG. 2 Photograph of Apparatus FIG. 3 Typical Pump Calibration Curve D109212 3gageconnectionontheviscometerbeforereconnectingthegage.Withtheentireviscometerassemb

31、led,circulatehydraulicoilwith the return valve open until all trace of air is eliminated. 9.2.1 The time to attain test temperature varies with the bath.At 54C (65F) the grease in an unstirred liquid bath should bereadytotestin2h.Airbathscantakeaslongas8h.AnASTMThermometer74Finthebathservesasaconven

32、ientsecondary means of measuring the temperature at 54C (65F). In an air bath the thermometer must be within 25.4 mm of the capillary. NOTE 5The use of an equivalent non-mercury lled replacement thermometer, such as a thermistors, platinum resistance thermometer, other liquid in glass thermometer, o

33、r thermocouple is under study in Subcommittee E20.09. 9.3 With No. 1 capillary in place and the 40-tooth gear connected, operate the pump with the return valve closed until equilibrium pressure is obtained. Record the pressure. Change to the 64-tooth gear and again establish equilibrium. Record and

34、relieve the pressure. Replace the No. 1 capillary with subsequent ones and repeat these operations until tests have been run with all capillaries at both ow rates. With some soft or hard greases, it cannot be practical to use all of the capillaries. NOTE 6It may be necessary to rell the cylinder wit

35、h fresh grease when all 16 determinations are to be made. NOTE 7The use of an equivalent non-mercury lled replacement thermometer is under study in Subcommittee E20.09. 10. Calculation 10.1 Calculate apparent viscosity of the grease as follows: happarentviscosity!5F/S (1) where F is the shear stress

36、, and S is the shear rate. Therefore: h5F/S5 ppR 2 /2pRL 4v/t!/pR 3 5ppR 4 /8Lv/t!5P68944pR 4 /8Lv/t! (2) where: p = pressure dynes/cm 2 , L = capillary length, cm, P = observed gage pressure, psi (multiply by 68944 to convert to dynes per square centimetre), R = radius of capillary used, cm, and v/

37、t = ow rate, cm 3 /s. 10.2 Calculations may be reduced to a minimum by preparing a table of 16 constants, one for each capillary and shear rate (Table 1). For example, viscosity with No. 1 capillary and the 40-tooth gear is given as follows: h5Pobserved!68944pR 4 /8Lv/t! orPK 1240! where: TABLE 1 Su

38、ggested Data Sheet for Recording Test Results (With Illustrative Test Values) Sample . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . No. 2 Grease Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25C Date . . . . . . . . . . . . .

39、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Nov. 1, 1948 Operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R.S. 1 2 3 4 A 5 B 6 A 7 C Capillary Gear Observed Pressure, P, psi K = 68944 pR 4 /(8Lv/t) Apparent Viscosity, n poises, = P K Shear Rate, S ,

40、 s 1 = (4v/t)/pR 3 Shear Stress, dynes per sq cm = n S 1 40 25.5 28.10 716 15 10 740 2 40 38.3 6.83 267 61 16 300 3 40 48.8 3.61 176 120 21 100 4 40 63.5 1.90 120 230 27 800 5 40 96.5 0.89 86 480 41 300 6 40 125 0.58 72.6 755 54 800 7 40 286 0.139 39.8 3 140 125 000 8 40 546 0.0464 25.3 9 320 235 50

41、0 1 64 29.5 17.60 520 24 12 470 2 64 45.8 4.27 195 98 19 100 3 64 60 2.26 135.5 195 26 400 4 64 82.3 1.19 97.9 370 36 250 5 64 130 0.556 72.4 770 55 800 6 64 165 0.363 59.9 1 220 73 200 7 64 384 0.087 33.4 5 020 167 500 8 64 720 0.029 20.9 14 900 311 000 A Values in this column are predetermined. B

42、Column 3 times Column 4. C Column 5 times Column 6. D109212 4K 1240! 568944pR 4 /8Lv/t! (4) 10.3 Also calculate the shear rates as follows: S54v/t!/pR 3 (5) Correct the ow rate to correspond to the observed pressure by reference to Fig. 3. Calculate 16 shear rates for the eight cap- illaries and two

43、 ow rates. This calculation need not be repeated for each run since it will remain constant until recalibration of the pump indicates a revision. D109212 510.4 Plot a curve of apparent viscosity versus shear rate on log-log paper, as shown in Fig. 4. NOTE 8Shear stresses also can be calculated by mu

44、ltiplying apparent viscosities by their corresponding shear rates. For solving various problems involving the steady ow of greases, shear stress-shear rate relationships may be plotted on appropriate charts. Instructions on the use of these charts are given in the article by Rein and McGahey. 3 11.

45、Precision and Bias 11.1 Due to the nature of the results, the precision of this test method was not obtained according to RR:D02-1007, Manual on Determining Precision Data forASTM Methods on Petroleum Products and Lubricants. The precision of this test method as determined by statistical examination

46、 of interlaboratory results is as follows: 11.2 The data in 11.2.1 and 11.2.2 should be used for judging the acceptability of results (95% condence) according to the concept of precision as given in Practice D3244. 11.2.1 RepeatabilityThe difference between two test results, obtained by the same ope

47、rator with the same apparatus under constant operating conditions on identical test material, would in the long run, in the normal and correct operation of the test method, exceed the values given in Table 2 only in one case in twenty. 11.2.2 ReproducibilityThe difference between two single and inde

48、pendent results obtained by different operators working in different laboratories on identical test material would, in the long run, in the normal and correct operation of the test method, exceed the values given in Table 2 only in one case in twenty. 11.2.3 Reproducibility of the curve drawing oper

49、ation varies from 5 to 8 % for the above samples. These data are based upon curve values of apparent viscosity at the six shear rates. A separate curve was drawn for each run. 11.3 BiasSince there is no accepted reference material suitable for determining the bias for the procedure in Test Method D1092, bias has not yet been determined. 11.4 There is no research report on Test Method D1092 because this test method was developed before research report guidelines were instituted, and are n