1、Designation: D7097 16aStandard Test Method forDetermination of Moderately High Temperature PistonDeposits by Thermo-Oxidation Engine Oil Simulation TestTEOST MHT1This standard is issued under the fixed designation D7097; the number immediately following the designation indicates the year oforiginal
2、adoption or, in the case of revision, the year 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. Scope*1.1 This test method covers the procedure to determine themass of depos
3、it formed on a specially constructed test rodexposed to repetitive passage of 8.5 g of engine oil over the rodin a thin film under oxidative and catalytic conditions at285 C. The range of applicability of the Moderately HighTemperature Thermo-Oxidation Engine Test (TEOST MHT2)test method as derived
4、from an interlaboratory study isapproximately 10 mg to 100 mg. However, experience indi-cates that deposit values from 1 mg to 150 mg or greater maybe obtained.1.2 This test method uses a patented instrument, method andpatented, numbered, and registered depositor rods traceable tothe manufacturer3an
5、d made specifically for the practice andprecision of the test method.41.3 The values stated in SI units are to be regarded asstandard.1.3.1 Although not an SI unit, the special name liter (L) isallowed by SI for the cubic decimeter (dm3) and the milliliter(mL) for the SI cubic centimeter (cm3). Like
6、wise, the specialname millimeter (mm) is allowed by SI as a measurement oflength.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 de
7、termine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:5D4485 Specification for Performance of Active API ServiceCategory Engine OilsD6335 Test Method for Determination of High TemperatureDeposits by Thermo-Oxidation Engine Oil SimulationTest3. Te
8、rminology3.1 Definitions of Terms Specific to This Standard:3.1.1 bubble airflow gauge, na precision bore glass tubemarked in tenths of a milliliter used to measure accurately theflow rate of air around and past the depositor rod and tocalibrate mass air flow controllers recommended for use in thepr
9、ocedure.3.1.2 depositor rod deposits, nparticulate matter formedon the depositor rod surface by oxidation of the thin film ofpassing oil exposed to the rod temperature and air, and weighedafter appropriate washing and drying to obtain the net massgain.3.1.3 filter deposits, nparticulates washed from
10、 the de-positor rod after the test and collected on a special multi-layerfilter cartridge.3.1.4 TEOST2, nan acronym for Thermo-Oxidation En-gine Oil Simulation Test.3.1.5 total rod deposits, nthe mass of deposits collectedon the depositor rod plus any mass of deposits washed from thedepositor rod an
11、d later extracted on a filter.3.1.6 volatilized oil, noil vapor coalesced on the mantlewall, and subsequently collected in a vial.3.2 Abbreviations:1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
12、Subcommittee D02.09.0G on Oxidation Testing of Engine Oils.Current edition approved Sept. 1, 2016. Published September 2016. Originallyapproved in 2005. Last previous edition approved in 2016 as D7097 16. DOI:10.1520/D7097-16A.2TEOST and MHT are registered trademarks of the Tannas Co. (Reg. 2001396)
13、,Tannas Company, 4800 James Savage Rd., Midland, MI 48642.3The sole source of supply of the apparatus known to the committee at this timeis Tannas Company, 4800 James Savage Rd., Midland, MI 48642. If you are awareof alternative suppliers, please provide this information to ASTM InternationalHeadqua
14、rters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1which you may attend.4The TEOST instrument, method and rod are patented. Interested parties areinvited to submit information regarding the identification of an alternative(s) to thispatented t
15、echnology to ASTM Headquarters. Your comments will receive carefulconsideration at a meeting of the responsible technical committee,1which you mayattend.5For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMSt
16、andards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.1 MHT2, nmoderately high
17、temperature.3.2.1.1 DiscussionThe TEOST MHT procedure evaluatesdeposit formation at temperatures that are closely related tothose of the piston ring zone in reciprocating engines (asdistinguished from the much higher temperatures associatedwith the TEOST 33C, Test Method D6335, procedure fordetermin
18、ing potential deposits in turbochargers).4. Summary of Test Method4.1 Deposit-forming tendencies of an engine oil underoxidative conditions are determined by circulating an oil-catalyst mixture comprising a small sample (8.4 g) of the oiland a very small (0.1 g) amount of an organo-metallic catalyst
19、.This sample mixture is then circulated for exactly 24 h in theTEOST MHT instrument over a special wire-wound depositorrod heated by electrical current to a controlled temperature of285 C at the hottest location on the rod. The depositor rod isweighed before and after the test and any deposit format
20、ion onthe rod as well as any deposits collected from rod washings aredetermined. During the test, precisely controlled and directedair is caused to bathe the oil flowing down the depositor rodand, thereby, to provide opportunity for oxidation. Precision ofthe test is strongly influenced by the care
21、in manufacture of thewire-wound steel depositor rods and the treatment of thecoating of the wound wire, the rate of air flow, and the amountand degree of mixing of the catalyst.5. Significance and Use5.1 The test method is designed to predict the deposit-forming tendencies of engine oil in the pisto
22、n ring belt andupper piston crown area. Correlation has been shown betweenthe TEOST MHT procedure and the TU3MH Peugeot enginetest in deposit formation. Such deposits formed in the ring-beltarea of a reciprocating engine piston can cause problems withengine operation and longevity. It is one of the
23、required testmethods in Specification D4485 to define API Category-Identified engine oils.66. Apparatus6.1 TEOST MHT Instrument,3with specific fittings for theMHT procedure including parts and assemblies are as follows:6.1.1 Depositor Rod Casing Assembly:6.1.1.1 Ceramic Isolators, special non-conduc
24、tive fittingsthat compress the depositor rod O-rings into the end-caps andcenters the depositor rod in the end-caps to prevent leakage ofoil from the lower end-cap. (See Figs. 4 and 5.)6.1.1.2 Depositor Rod, Wire-Wound, a specially patented,numbered, and registered steel tube wound with pretreatedst
25、eel wire. The steel tube is formed to a selected interiordiameter to precisely contact the surface of a metal-sheathedthermocouple. The registered depositor rods are required to runthe TEOST MHT procedure. (See Fig. 4, Fig. 5, and Fig. 7.)NOTE 1Precision of the TEOST MHT procedure is highly dependen
26、ton the uniformity of manufacture and use of patented and registereddepositor rods. Each depositor rod is numbered and traceable to themanufacturer and raw steel tubing mill.6.1.1.3 End-cap, Upper, holds the upper end of the glassmantle and depositor rod in place and allows air and oil to enterthe d
27、eposit-forming zone separately. (See Fig. 4 and Fig. 7.)6.1.1.4 End-cap, Lower, holds the lower end of the glassmantle and depositor rod in place and provides an outlet for theoil to pass into the sample flask and subsequently to therecirculating pump inlet tubing. (See Fig. 6.)6.1.1.5 End-cap Nuts,
28、 Four, used for compressing smallO-rings around depositor rod and for positioning and sealingthe oil feed tube and sealing the air inlet tubing. (See Fig. 4 andFig. 5.)6.1.1.6 Glass Mantle, the glass casing that surrounds thedepositor rod and diverts volatilized oil into a collecting vial.(See Figs.
29、 4-6.)6.1.1.7 Mantis Clip, a wire-spring device holding thesample flask in place on the lower end-cap. (See Fig. 2 and Fig.6.)6.1.1.8 Lower End-cap Seal, a flexible oil temperatureresistant rubber seal (see Fig. 9).6.1.1.9 Oil Feed Tube, the avenue for oil to be deliveredfrom the pump to the top of
30、the depositor rod.6.1.1.10 End cap O-rings, Large, Petroleum-resistant, cre-ate a seal between the end-caps and glass mantle. (See Fig. 5.)6.1.1.11 End cap O-rings, Small, Petroleum- and Heat-resistant, creates an air and fluid seal between depositor rodand end-caps. (See Fig. 5.)6.1.1.12 Pump Outle
31、t Tubing, a flexible transparent vinyltube of 3.2 mm outer diameter with a flared end used totransport the oil sample from the oil pump to the oil feed tube.(See Fig. 6.)6.1.1.13 Sample Flask, a small (25 mL), modified form ofan Erlenmeyer flask with sidearm into which the catalyst andsample are fir
32、st weighed, then later used to feed the sample tothe circulating system. (See Fig. 2 and Fig. 6.)6.1.1.14 Stainless Steel Hex Screws and Busbar End Piece,these secure the depositor rod to the busbars.6.1.1.15 Thermocouples, Two, stainless steel sheathed,1.57 mm diameter by 150 mm length. One, a J-ty
33、pe, is used forcontrolling the test temperature (depositor rod) while the other,a K-type, is used to protect against an over-temperaturecondition.6.1.1.16 Thermocouple Locking Collar, a fitting that can betightened on the thermocouple to ensure the thermocouple tipis at the correct position when pla
34、ced inside the depositor rod.(See Fig. 4.)6.1.1.17 Volatiles Vial Clip, the device that holds the vola-tiles collection vial in place on the mantle. (See Fig. 4.)6.1.2 Airflow Control Assembly, sets air flow at chosen flowrate.6.1.2.1 Bubble Airflow Gauge, a device for precisely estab-lishing the ai
35、rflow rate and calibrating the flow meter from1 mLmin to 30 mLmin. (See Fig. 1.)6.1.2.2 Calibrated Flow Meter, capable of measuring ap-proximately 1 mLmin to 20 mLmin of air and providing acontinuous reading on airflow rate when calibrated.6Selby, T. W., and Florkowski, D. F., “The Development of th
36、e TEOST ProtocolMHT Bench Test of Engine Oil Piston Deposit Tendency,” Supplement to theProceedings of the 12th Esslingen Colloquium, Esslingen, Germany, January 11-13,2000, pp. 55-62.D7097 16a26.1.2.3 Handheld Digital Flow Meter, an optional device tomonitor air flow to or out of the mantle, capabl
37、e of reading aflow rate of 10.0 mLmin 6 0.1 mLmin of air.6.1.2.4 Precision Digital Mass Flow Controller, an optionaldevice that allows the precise control of the input air flow. (SeeFig. 1a.)6.1.2.5 Stopwatch, reading to 1/100 s.6.1.3 Filtering Flask Assembly, provides the means forfiltering particl
38、es washed from the depositor rod. (See Fig. 8.)6.1.3.1 Filter Cartridge, a special multilayer filter made forthe TEOST MHT procedure fitting the end of the filter funnelalso made for the TEOST procedure. (See Fig. 8.)6.1.3.2 Filter Funnel, a special combination funnel of400 mL capacity, necking down
39、 to a 10 mL graduated orFIG. 1 Bubble GaugeD7097 16a3non-graduated section that, in turn, ends in a glass or Luer-locktip fitting the special filter cartridge used in the procedure. (SeeFig. 8.)6.1.3.3 Filter Tube Assembly, a metal or polyethylene tubeinserted through a No. 8 rubber stopper in the v
40、acuum flask tofit the lower outlet of the filter cartridge. (See Fig. 8.)6.1.3.4 Vacuum Flask, 1000 mL capacity for collecting thehydrocarbon solvent and oil during the filter rinse.6.1.3.5 Vacuum Source, a vacuum source sufficient to drawthe hydrocarbon solvent and oil through the filter and provid
41、ethe necessary filter drying.6.1.3.6 Wire Rod, a thin, clean, stainless steel wire rod, fordislodging any deposits trapped in the narrow portion of thefilter funnel just above the filter.6.2 Ancillary Equipment, needed or helpful:6.2.1 Balance, capable of weighing deposits to the nearest0.1 mg with
42、a minimum capacity of 100 g.6.2.2 Catalyst Syringe, a small glass syringe that uses eithera glass or PTFE plunger (do not use rubber plunger) of 100 Lcapacity, for carefully metering the catalyst being weighed intothe sample flask. (An optional approach is to use a smalldisposable glass pipet.)6.2.3
43、 Oil Sample Transfer Pipettes, disposable glass orplastic pipettes or droppers.6.2.4 Oil Extraction Test Tubes, three glass test tubes ofsufficient height to cover all but the upper 20 mm of an inserteddeposit-carrying rod. Plastic tubes are not acceptable.6.2.5 Temperature Recorder, an optional dev
44、ice for trackingthe temperature of the upper depositor rod thermocouple overthe 24 h period of the test.6.2.6 Thermocouple Depth Insertion Gauge, an optionalmeasurement device fabricated for simple setting and checkingof the thermocouple insertion depth, using a millimeter gradu-ation scale.6.2.7 Vi
45、als and Caps, a vial and matching cap of 10 mL ormore in volume with an 11.5 mm diameter mouth and an outerdiameter of 20 mm to collect the volatile material emitted bythe oil and collected on the mantle wall during the test as wellas the recovered, end-of-test oil sample. (See Fig. 4.)6.2.8 Weighin
46、g Boat, a light, circular or oblong weighingcontainer, preferably made of aluminum with a diameter orlength of 7 cm to 10 cm and notched in two diametricallyopposed places to prevent the rod from rolling. (See Fig. 3.)6.2.9 Air-Flow Restrictora small PTFE washer designedto limit the amount of air al
47、lowed to pass between the sampleflask and the drain on the lower end-cap.7. Reagents and Materials7.1 Abrasive Paper, 800-grit emery (aluminum oxide).7.2 Acetone, particle-free, reagent grade, for final cleaningof new depositor rods. (WarningFlammable. Health haz-ard.)7.3 Air, oil-free, clean, and d
48、ry, obtained from cylinder gasor house line, regulated to 15 kPa to 100 kPa (2 psi to 15 psi)at more than 690 kPa (100 psi).7.4 Cyclohexane or Other Alkane Hydrocarbon Solvent,reagent grade. (WarningFlammable.) Cyclohexane is theonly allowed naphthenic hydrocarbon. Do not use any aromatichydrocarbon
49、s. Throughout the further description of the test,the solvent selected is referred to as “hydrocarbon solvent.”7.4.1 The volatility of the cyclohexane as the solventensures timely evaporation of the deposits on the rod and filter.If another alkane hydrocarbon is used as the solvent, longerdrying times may be required. The higher the purity of thesolvent, the quicker the solvent should evaporate.7.5 Catalyst3Catalyst contains iron, lead, and tin in ratioschosen for emulating engine deposit conditions.7.5.1 For long term storage, it is acceptable to refriger
