1、Designation:D487106 Designation: D4871 11Standard Guide forUniversal Oxidation/Thermal Stability Test Apparatus1This standard is issued under the fixed designation D4871; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、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. Scope*1.1 This guide covers an apparatus used to measure the oxidation or thermal stability of liquids by subjecting them totem
3、peratures in the range from 50 to 375C in the presence of air, oxygen, nitrogen, or other gases at flow rates of 1.5 to 13 L/h,or in the absence of gas flow. Stability may be measured in the presence or absence of water or soluble or insoluble catalysts. Gasesevolved may be allowed to escape, conden
4、sed and collected, or condensed and returned to the test cell.1.21.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It
5、 is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D91 Test Method for Precipitation Number of Lubricating OilsD156 Test Method for Sa
6、ybolt Color of Petroleum Products (Saybolt Chromometer Method)D445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)D664 Test Method for Acid Number of Petroleum Products by Potentiometric TitrationD974 Test Method for Acid and Base Number b
7、y Color-Indicator TitrationD1500 Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)D3339 Test Method for Acid Number of Petroleum Products by Semi-Micro Color Indicator TitrationD5763 Test Method for Oxidation and Thermal Stability Characteristics of Gear Oils Using Universal Glassw
8、areD5770 Test Method for Semiquantitative Micro Determination of Acid Number of Lubricating Oils During Oxidation TestingD5846 Test Method for Universal Oxidation Test for Hydraulic and Turbine Oils Using the Universal Oxidation Test ApparatusD6514 Test Method for High Temperature Universal Oxidatio
9、n Test for Turbine Oils3. Summary of Guide3.1 An apparatus is described in which a sample of test fluid, typically from 100 ml or 100 g, is subjected to thermal or oxidativedegradation or both. Insoluble or soluble catalyst may be added. Gas may be bubbled through the liquid to provide agitation ort
10、o promote oxidation or both. Water or water vapor may be added. At the end of the test or at intervals throughout the test, theliquid is monitored for change in neutralization number, viscosity, weight loss, formation of sludge, or for other parameters. Thecorrosivity of the fluid toward any catalys
11、t metals can be determined from the appearance and weight change of the metal testspecimens, if present, or by monitoring the oil and any sludge or water for metal content. The test is terminated after a fixed timeperiod or when a selected parameter reaches a condemning value.NOTE 1The volume of liq
12、uid at test temperature should be sufficient to cover the catalysts and should not extend beyond the heated portion of thebath.4. Significance and Use4.1 This standard describes an apparatus that provides the versatility required to conduct oxidation or thermal stability tests onliquids using a wide
13、 variety of test conditions. It is sufficiently flexible so that new test conditions can be chosen in response tothe changing demands of the marketplace.1This guide is under the jurisdiction of ASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D
14、02.09.0D onOxidation of Lubricants.Current edition approved MayDec. 1, 2006.2011. Published May 2006.January 2012. Originally approved in 1988. Last previous edition approved in 20002006 asD487100.D487106. DOI: 10.1520/D4871-06.10.1520/D4871-11.2For referenced ASTM standards, visit the ASTM website,
15、 www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication
16、of what changes have been made to the previous version. Becauseit 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 versionof the standard as published by ASTM is to be consider
17、ed the official document.*A Summary 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.4.2Procedures4.2 Procedures using this apparatus are described in the following ASTM standard t
18、est methods: D5763, D5846,and D6514. Other procedures may be in use, but they have not been developed as ASTM standard test methods.5. Apparatus5.1 Heating Block, as shown at the lower right in Fig. 1, to provide a controlled constant temperature for conducting tests.5.1.1 Test cells are maintained
19、at constant elevated temperature by means of a heated aluminum block which surrounds eachtest cell.5.1.2 Holes in the aluminum block to accommodate the test cells shall provide 1.0 mm max clearance for 38-mm outsidediameter glass tubes. The glass test cells shall fit into the block to a depth of 225
20、 6 5 mm.NOTE 2The original test blocks were made with spaces for ten test cells. Blocks with different number of holes are acceptable if other requirementsare met.5.1.3 The heating system shall be geometrically and thermally balanced. For thermal balance, sizes and locations of the heatersare propor
21、tioned against heat losses.5.1.4 The block is cylindrical and constructed from forged aluminum. The block has a minimum thickness of 38 mm ofinsulation on all sides, top and bottom. An insulation of thermally efficient ceramic fiber material is suggested.5.1.5 The exterior jacket, sides and top are
22、stainless steel or equivalent.5.1.6The block is equipped with a well for a thermocouple for temperature control and measurement, and a thermometer wellfor temperature calibration.5.1.6 The block is equipped with a well for a temperature measuring device and a thermometer.5.2 Temperature Control Syst
23、em, as shown at lower left in Fig. 1, to maintain the heating block at a set temperature.FIG. 1 Universal Oxidation Test ApparatusD4871 1125.2.1 The temperature controller shall be capable of maintaining the block temperature within 60.5C of the desired testtemperature for the duration of the test.
24、The preferred controller shall have proportional and integral control modes, and a heatermalfunction alarm.5.2.2 The range for operation is from at least 50 to 375C. (WarningAn adjustable deviation alarm that automatically shutsdown the system if temperature varies outside preset limits is desirable
25、 as a safety feature and to avoid erroneous test results. Aseparate adjustable high temperature monitor and shutoff is desirable as a safety device.)5.2.3 Temperature control and uniformity is the most important parameter affecting test result precision. Therefore, the heatingsystem design is critic
26、al. Temperature from hole-to-hole and at all sides of each hole in the block shall be uniform within the 0.5Ctolerance of the total system.5.3 Gas Flow Control System, as shown in Fig. 1, to provide air or other gases to each test cell.5.3.1 A gas flow controller is required for each test cell, to p
27、rovide air or other desired gases. (Warning If reactive gases areto be used in the test procedure, all fittings in the gas control system must be compatible with these gases.)5.3.2 The standard gas flow range shall be from 1.5 to 13 L/h. Flowmeters shall have a scale length sufficiently long to perm
28、itaccurate reading and control to within 65 % of full scale. Floats and tubes may be interchangeable for alternate gas flow ranges.5.3.3 The system shall have a pressure regulator to provide constant inlet pressure and 10 flow indicators with individual,integral needle valves with regulating stems f
29、or flow adjustment.5.3.4 The total system accuracy shall meet or exceed the following tolerances:5.3.4.1 Inlet pressure regulator within 0.34 kPa (0.05 psig) of setpoint,5.3.4.2 Total flow control system reproducibility within 7 % of full scale, and5.3.4.3 Repeatability of measurement within 0.5 % o
30、f full scale.5.4 Alternative DesignsThe equipment in 5.1-5.3 represents a preferred configuration. Alternative apparatus designs forsample heating, and for temperature and flow control shall be acceptable providing they are shown to maintain temperature andgas flow within the specified limits.5.5 Gl
31、assware (Note 3), is used to contain the test sample, deliver gas into the sample, and collect, carry off or returncondensable volatiles.NOTE 3Not all glassware is used in a single test procedure.5.5.1 Test Cell, borosilicate glass, standard wall; 38-mm outside diameter, 300 6 5-mm length, with open
32、 end fitted with a 34/45standard-taper, ground-glass outer joint (Note 4). See Fig. 2.NOTE 4Initial lots of glassware were made with 45/50 standard-taper, ground-glass joints. These are also acceptable for test work; however, the 34/45joints are preferred.5.5.2 Condenser, Allihn-Type, borosilicate g
33、lass, 3306 5-mm jacket, 34/45 standard-taper ground-glass inner joint on lower end.Upper opening must admit gas delivery tube. See Fig. 2.5.5.3 Gas Inlet Tube I, 8-mm outside diameter, 850 6 5 mm long, lower end with fused capillary 1.5 to 3.5 mm inside diameter.The capillary bore shall be at 15 6 1
34、 mm long. The lower tip is cut at a 45 angle. The gas inlet tube may optionally include aglass ring 15 mm in diameter to support washer-type catalysts, or the support ring (see 5.5.8), from which catalyst specimens maybe suspended. The position of the ring on the gas inlet tube shall be specified in
35、 the test method requiring such catalyst support.The gas inlet tube I is illustrated in Fig. 2 with a glass ring suitable for support of washer-type catalyst.5.5.3.1 The 850-mm tube is required for testing configurations using the condenser and sampling head or the intermediate headin order that the
36、 tube extend beyond the top of the condenser so that a gas supply hose can be attached. A tube of shorter lengthFIG. 2 ApparatusD4871 113may be substituted when other assemblies are used, provided it is long enough to attach the gas supply.5.5.4 Gas Inlet Tube II, 8-mm outside diameter 455 6 5 mm lo
37、ng, lower tip cut at 45 angle. The top 50 mm of the tube mayoptionally be bent at a 90 angle. See Fig. 2.5.5.5 Basic Head, with 34/45 standard-taper, ground-glass inner joint, opening for gas inlet tube, septum port for samplewithdrawal, and exit tube to conduct off-gases and entrained vapors. Overa
38、ll length shall be 125 6 5 mm. The head shall havean adapter by which an air-tight seal may be made with the gas inlet tube.3The septum port is preferably designed to accept a flatpolytetrafluoroethylene (PTFE)-faced silicone septum such as used with gas chromatographic instrumentation. See Fig. 3.5
39、.5.6 Intermediate Head, with standard-taper inner joint at bottom for test cell and outer joint at top for condenser. Overalllength shall be 170 6 5 mm. The outlet for removal of off-gases and condensed liquids is located far enough below the gas-escapeholes to ensure that condensed liquid will exit
40、 through the side tube rather than returning to the test cell. A septum port (same asin 5.5.5) is provided for sample withdrawal. See Fig. 3.5.5.7 Sampling Head, with standard-taper inner joint at bottom for test cell and outer joint at top for condenser. Overall lengthshall not exceed 175 mm. A sep
41、tum port (same as in 5.5.5) is provided for sample withdrawal. See Fig. 3.5.5.8 Support Ring, 9.5-mm inside diameter, 12.7-mm outside diameter, 7 mm long, to fit on inlet tube I fitted withhigh-mounted glass ring. Four glass hooks are spaced at 90 intervals from which catalyst coupons may be suspend
42、ed. See Fig.3.5.5.9 Spacer Ring, 9.5-mm inside diameter, 12.7-mm outside diameter, 7 mm long, to fit on inlet tube I fitted with low-mountedglass ring. The spacer is added to separate metal washers used as catalyst and corrosion test specimens. See Fig. 3.6. Procedure6.1 Test Conditions:6.1.1 Stabil
43、ity tests can be run for a fixed time period, with measurement of selected parameters at the end of the test periodor at intervals throughout the test.6.1.2 Stability tests can be run until a predetermined failure point, with measurement of selected parameters to determine failure.Samples of fluid a
44、re withdrawn at intervals to measure changes in the parameters.6.1.3 Fixed time tests are convenient for setting performance specifications; variable time tests can offer more usefulinformation in screening tests and evaluating formulation changes.6.2 Possible test parameters that can be monitored i
45、nclude:6.2.1 Change in acid number (Test Methods D664, D974, D3339, or D5770),6.2.2 Change in precipitation number (Test Method D91),6.2.3 Change in viscosity (Test Method D445),6.2.4 Change in color of fluid (Test Methods D156 or D1500),6.2.5 Evaporation loss from test fluid,6.2.6 Formation of an i
46、nsoluble sludge,3A Wheaton-type thermometer adapter is suitable, with an O-ring seal. All wetted parts should be of poly-tetrafluoroethylene (PTFE) or similar inert material.FIG. 3 ApparatusD4871 1146.2.7 Formation of a spot on a test blotter,6.2.8 Formation of varnish,6.2.9 Change in weight of cata
47、lyst specimens,6.2.10 Change in appearance of catalyst specimens,6.2.11 Weight of material volatilized from sample, and6.2.12 Acid number of volatilized material (Test Method D3339 or D5770).7. Keywords7.1 accelerated testing-petroleum products; gear oil-stability test apparatus; hydraulic oil-stabi
48、lity test apparatus; oxidationtesting-petroleum; stability-oxidation; stability-thermal; turbine oil-stability test apparatus; universal oxidation test apparatusSUMMARY OF CHANGESSubcommittee D02.09 has identified the location of selected changes to this standard since the last issue(D4871006) that
49、may impact the use of this standard.(1)Added Test Methods D5763, D5846, and D6514 to Section 2.(2)Added 4.2 to include Test Methods D5763, D5846, and D6514) The type of acceptable device used to measure and controltemperature is broadened from only a thermocouple to any appropriate temperature measuring device in 5.1.6.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent ri
