SH/T 0755-2005 Thermal oxidation stability evaluation method for manual transmission fluids and rear axle oils (L-60-1 method)

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Card type: Test method

1. Method number / full name / English name / replacement relationship

• Standard number: SH/T 0755-2005
• Chinese name: Thermal oxidation stability evaluation method for manual transmission fluids and rear axle oils (L-60-1 method)
• English name: Standard test method for evaluation of the thermal and oxidative stability of lubricating oil used for manual train-iccions and final drive axles (requires confirmation against the source standard (source-text extraction): in the original English name, "train-iccions" is suspected to be source-text extraction noise of "transmissions")
• Method number: L-60-1 method
• Replacement relationship: not provided in the available source
• Adoption relationship: modified adoption of ASTM D5704-00a "Standard Test Method for Determining Thermal Oxidation Stability of Lubricating Oils for Manual Transmissions and Rear Axles"
• Publication/implementation: published by 2005-04-11, implemented by 2005-09-01
• Publishing unit: National Development and Reform Commission of the People's Republic of China
• Drafting unit: Lubricant Research and Development Center of PetroChina Company Limited
• Main drafters: Zhang Kuande, Cai Jiyuan, Wei Kongyin, Wei Tiesheng
• Secretariat: Sinopec Research Institute of Petroleum Processing
• Proposed by: China Petrochemical Corporation

2. Scope of application and non-applicability

• 1.1 This standard specifies a test method for evaluating the thermal oxidation stability of automotive manual transmission fluids and rear axle oils on a L-60-1 test machine.
• 1.2 This test method was developed with reference to the L-60 test. This method is generally used to determine the viscosity increase, insoluble formation, and deposition characteristics of manual transmission and rear axle lubricating oils under high-temperature oxidizing conditions.
• 1.3 This standard method does not mention the safety problems existing during use. Users of this method are responsible for taking appropriate safety and protective measures and for establishing corresponding rules and regulations before use. Specific hazard descriptions are given in 6.1.2 and Appendix B.
• Non-applicable scope: not explicitly listed in the available source.

3. Method principle

In a heatable gearbox equipped with two spur gears, one test bearing, and a copper catalyst, add the lubricating oil sample to be tested. When the oil is heated to the specified temperature, operate the gears under predetermined load and speed conditions 50h. Air is introduced into the lubricating oil at a certain rate, and the oil temperature is controlled throughout the test. After the test, the parameters for evaluating the degree of oil deterioration include oil viscosity increase, insoluble formation in the used oil, and gear cleanliness. (Chapter 4 Method summary)

4. Reagents and materials (purity / preparation)

6.1 Reagents

• 6.1.1 Petroleum ether: complies with GB/T 15894 standard.
• 6.1.2 Aviation washing gasoline: complies with the SH 0114 aviation washing gasoline standard.
• Note: The organic cleaning solvents used are flammable and harmful to health; see Appendix B.

6.2 Materials

• 6.2.1 Compressed air: the quality of the compressed air complies with the requirements of GB/T 4830.
• 6.2.2 Copper strip catalyst: cold-rolled electrolytic copper shall satisfy UNS (Unified Numbering System) C11000. The dimensions of the two copper strips are approximately 14mm × 46mm × 1.6mm.
• 6.2.3 Sandpaper: 360 grade water sandpaper.

5. Instruments and equipment

The test equipment uses a L-60-1 test machine (for the structure of the test machine, see A.1 in Appendix A).

• 7.1 Gearbox: gearbox assembly, including a new test bearing, a pair of new test gears, copper strip catalyst, new lip seals and O type O-rings, and the lubricating oil to be tested. To meet the requirements of this test method, the gearbox has been redesigned and improved on the basis of the original design. The gearbox and related accessories shall be assembled according to the given drawings. The gearbox and related accessories shall meet the required dimensions, materials, and surface roughness according to the overall design. In this design, a combination of lip seals and O type O-rings is used to replace the cork gaskets and oil retaining rings selected in the early design.
• 7.2 Insulated oven: surrounds the gearbox assembly, insulating it and heating and maintaining the lubricating oil temperature at the test temperature. The oven is equipped with a heater and a heating blower; the dimensions of the oven and the positions of the heater, blower, and oven temperature sensor are clearly marked in the figure. Their approximate positions are marked in Figure A.1 in Appendix A.
• 7.3 Heating elements: because the test procedure is very sensitive to temperature changes, the following special heating elements (two in total) are defined:
  • Main heating element, only one is allowed.
  • Alternator load heater, only one is allowed.
• 7.4 Temperature controller: proportional-integral-derivative (PID) control type, with adjustable output percentage.
• 7.5 Thermocouple: to determine, record, and control the test oil temperature, a "J" type thermocouple with a diameter of 3.2mm is required. Thermocouples used for measuring other temperature values shall meet the operator's requirements, but all thermocouples shall be installed behind the baffle of the gearbox assembly and shall not interfere with normal oil flow during the test.
• 7.6 Temperature recorder: use the specified thermocouple and temperature control system and a suitable recorder. The test temperature variation curve shall be listed in the test report.
• 7.7 Alternator: the alternator used for loading shall be the specified product; substitute products are not allowed. The wiring of the alternator shall be modified according to the specific drawings; for modification of the alternator load circuit, see Appendix A.2.
• 7.8 Heater blower: the heater blower system shall deliver air to the insulated oven through a blower opening with a diameter of 54mm at a speed of 1557U/min±142U/min (under free-flow conditions). (requires confirmation against the source standard (source-text extraction): the original text "1557U/min±142Unr in" is suspected to be "1557L/min±142L/min" or a similar flow unit, with severe source-text extraction noise) The heater blower shall be a skeleton-type blower driven by an electric motor or by a toothed belt from the main drive shaft. In any case, the air flow rate should be controlled at the set value just like maintaining other test parameters.
• 7.9 Air flow controller: the air flow controller sets the air pressure to 6.9kPa±0.7kPa and the flow rate to 1.1L/h±0.1L/h.
• 7.10 To keep the air flow meter reading stable, it is recommended to add a surge tank on the air line.
• 7.11 Test gears: one pair of machine tool speed-change gears, one with 34 teeth, the other with 50 teeth, both with a tooth width of 9.5mm.
• 7.12 Test bearing: R-14 ball bearing.
• 7.13 Sealing O type rings, O type rings for the seal plate, and O type rings for the cover plate.
• 7.14 Lip seals: two shaft seals.
• 7.15 All new equipment shall be assembled according to the drawings provided in Appendix A to meet standardization requirements.

6. Recommended operating conditions

• Test oil temperature: 162.8℃±0.6℃ (10.3)
• Time for the test oil temperature to rise from room temperature to 162.2℃: greater than 45min, but shall not exceed 60min (10.3)
• Oven temperature set value: shall not be higher than 204℃ (10.3.2)
• Air pressure: 6.9kPa±0.7kPa (10.2)
• Air flow rate: 1.1L/h±0.1L/h (10.2)
• Alternator output power: 128W±15W (10.4)
• Large gear speed: 1750r/min±50r/min (10.5)
• Test cycle: 50.0h±0.1h (10.7)
• Test oil charge amount: 120mL±5mL (10.1)

7. Sampling and sample preparation

• 10.1 Weighing the test oil: use a clean graduated cylinder to measure 120mL±5mL of test oil and weigh it, then pour the test oil into the gearbox. Weigh the graduated cylinder again to determine the mass of test oil added and record it, accurate to 0.01g.
• 8.3 Cleaning the test gearbox: clean the gearbox, exhaust pipe, exhaust pipe deflector, baffle bushing, seal sleeve, gearbox cover plate, seal plate, nuts, studs, flat washers, oil baffle, gasket ring, bearing sleeve, clamp, pin, shaft end, shaft end nut, catalyst holder, air supply pipe, etc. (because the test depends to a large extent on the precision of machined surfaces, take care to protect the surfaces of all parts during cleaning; do not use metal brushes or adherent cloths other than those specified in clause 8.4 for scrubbing). Nylon brushes and long tube-wall cleaners may be used for auxiliary cleaning; first clean the above parts with aviation washing gasoline, then with petroleum ether, and air-dry.
• 8.4 Cleaning the test gears: carefully inspect the surfaces of the test gears for scratches; if there are obvious defects, they may be polished with an oilstone; first polish all surfaces of the test gears with 360 grade water sandpaper, then clean with aviation washing gasoline, and finally clean with petroleum ether and air-dry.
• 8.5 Cleaning the test bearing: before installation, clean the surface of the test bearing successively with aviation washing gasoline and petroleum ether, and air-dry.
• 8.6 Cleaning the copper strip catalyst:
  • 8.6.1 For ease of identification, file a notch on one side of a copper strip as a mark; the notch shall be triangular on the long edge of the copper strip, and the length of each side of the triangular notch is 5mm.
  • 8.6.2 Polish all surfaces of the copper strip catalyst with 360 grade water sandpaper.
  • 8.6.3 Clean the surface of the copper strip successively with aviation washing gasoline and petroleum ether, and air-dry.
  • 8.6.4 Before installation, weigh the copper strip catalyst marked with the triangle, accurate to 0.0001g. Use tweezers or filter paper to handle the cleaned copper strip; do not touch it directly with hands.

8. Analytical procedure

8. Test preparation

• 8.1 Setting the insulated oven temperature: after final assembly is completed, set the oven temperature to 204℃, insert the temperature sensor from the upper surface to 75mm, turn on the heater and circulation fan, and when the temperature reaches 204℃, adjust the temperature controller to turn off the heater. The heating oven temperature control should meet the heating requirements in clause 10.3.
• 8.2 Operation of temperature recording and control instruments: because the test process is extremely sensitive to temperature, it is necessary to periodically calibrate the accuracy of the components related to temperature measurement and control. Therefore, after the new test equipment is installed and before conducting the reference oil test, the instruments for measuring and recording the oven temperature and test oil temperature should be calibrated. For example, the test oil temperature thermocouple and controller should be calibrated. This can be done by inserting the probe into an auxiliary temperature-controlled oil bath equipped with a stirrer. The oil bath temperature is accurately controlled at 162.8℃; before the test, the accuracy of the test detection system should be ensured.
• 8.7 Gearbox installation (see the exploded view of components in A.3 in Appendix A):
  • 8.7.1 Before installing the gearbox, first inspect the parts allowed to be reused; if there is severe wear, they should be replaced.
  • 8.7.2 New sealing elements (O type O-rings and lip seals) shall be used for each test.
  • 8.7.3 Install the baffle shaft sleeve and the seal sleeve. If the seal sleeve is damaged, replace it immediately.
  • 8.7.4 Install the lip seal and the O type O-ring on the seal plate. Gasket sealant should be used at the lip seal to prevent oil leakage.
  • 8.7.5 When installing the seal plate in the gearbox, a flat gasket should be used to avoid damage to the seal plate surface. The tightening torque for the seal plate positioning bolts is 2.8N·m.
  • 8.7.6 Install the external lock rings on the upper shaft and the lower shaft respectively.
  • 8.7.7 Install the upper and lower gasket spacer rings on the upper shaft and the lower shaft respectively.
  • 8.7.8 Secure the protective baffle and the catalyst holder, and tighten the fixing bolts to a torque of 2.8N·m.
  • 8.7.9 Install the bearing into the bearing fixture with the side bearing the bearing manufacturer's number facing outward. Tighten the bearing fixture bolts to a torque of 2.8N·m.
  • 8.7.10 Insert the test bearing bushing into the test bearing from the side with the bearing manufacturer's number. Then install this bearing assembly on the lower shaft.
  • 8.7.11 Install the large gear (GA-50) on the lower shaft and the small gear (GA-34) on the upper shaft along the shaft key direction. When installing the test gears, the side with the manufacturer's name should face outward. Tighten the positioning nuts to a torque of 10.0N·m. Warning: The gear positioning nuts are different. Because the lower shaft has a right-hand thread, and the upper shaft has a left-hand thread.
  • 8.7.12 Insert the test oil thermocouple from the inclined right wall of the gearbox, keeping the thermocouple perpendicular to the insertion surface, with an insertion depth of 13mm±1mm.
  • 8.7.13 Place the copper strip catalyst in the catalyst holder slot. The size of the copper strip catalyst should match the catalyst holder to avoid movement of the catalyst during the test. Place the notched copper strip at the rear of the gearbox, with the copper strip opening facing backward, so as to minimize the effect on deposits when removing the copper strip catalyst after the test.
  • 8.7.14 Install the O type O-ring on the gearbox cover plate.
  • 8.7.15 Install the gearbox cover plate, and tighten the bolts to a torque of 2.8N·m.
• 8.8 Air supply line: Check the air supply line to ensure it is unobstructed, and place the air supply line and thermocouple wires together at the lower right side of the gearbox to avoid damage.
• 8.9 Installation of the insulated oven cover plate: Insert the thermocouple for measuring the oven temperature from the upper part of the oven cover plate to a depth of 75mm, then install the cover plate.
• 8.10 Air flow calibration: Use a standard air flow meter for calibration. The air flow controller is required to be calibrated once a year so that it meets the flow specification requirements, that is, inlet pressure 101.86kPa, flow rate 1.1L/h. Connect the calibration instrument in series to the air line, and adjust the inlet pressure to 101.86kPa, flow rate 1.1L/h, put a commercially available oil sample of grade 80W/90 into the gearbox, start the test machine and reach the test conditions. After completing the calibration, remove the calibration instrument.

9. Calibration of the test machine

• 9.1 To ensure consistent test results, a reference oil should be selected to calibrate the test machine.
• 9.2 Calibration of a new test stand: For a new test stand, conduct a calibration test with reference oil, and the results should be within the required range.
• 9.3 Test stand calibration interval: After every 10 tests, conduct a reference oil calibration test on the test stand.
• 9.4 Before each test, the tests conducted on that stand should be registered in sequence by number of runs. All tests, including startup failures and invalid operations, should be counted in the number of tests.

10. Test procedure

• 10.1 Weighing of test oil: Use a clean graduated cylinder to measure 120mL±5mL of test oil and weigh it, then pour the test oil into the gearbox. Weigh the graduated cylinder again to determine the mass of test oil added and record it, accurate to 0.01g.
• 10.2 Air pressure setting: Set the air pressure to 6.9kPa±0.7kPa and the flow rate to 1.1L/h±0.1L/h.
• 10.3 Test machine startup and test oil heating: Turn on the main drive motor and fan, record the startup time. The temperature control system will automatically heat the test oil temperature to 162.8℃±0.6℃, record the heating time. The time for the test oil temperature to rise from room temperature to 162.2℃ should be greater than 45min, but must not exceed 60min. If the heating time is less than 45min or greater than 60min, the test is invalid.
  • 10.3.1 During the heating process, record all test parameters every 15min. If there is a reading that exceeds the range specified by the test conditions, it can be considered that the parameter is out of specification for the entire 15min.
  • 10.3.2 If the test oil heating time is less than 45min, reduce the oven temperature so that the heating time is greater than or equal to 45min, but less than 60min. One reason for a heating time exceeding 60min is that the insulated oven and oven cover plate are not tightly sealed; another reason is heat leakage from other parts of the oven, or both. However, in any case, the oven temperature setpoint must not be higher than 204℃, to ensure stable equipment performance.
• 10.4 Alternator output power setting: Adjust the alternator output power to 128W±15W.
• 10.5 Large gear speed: During heating and testing, the large gear speed is always maintained at 1750r/min±50r/min.
• 10.6 Formal test:
  • 10.6.1 After the test starts, if the test is interrupted for more than 5min, the test is invalid; the test should be terminated and the time and reason recorded.
  • 10.6.2 Record all operating parameters once every hour. If there is a reading that exceeds the range specified by the test conditions, it can be considered that the parameter is out of specification for the entire one hour.
• 10.7 Calculation of test oil mass loss: After the test has run for 50.0h±0.1h, the test ends; turn off the power in sequence. Put the test oil into a clean container whose mass has been measured, drain the oil for 30min, then weigh and record the mass of the drained sample. Use formula (1) to calculate the mass loss of the test oil, expressed as mass fraction. When the test oil mass loss exceeds 20%, the test is considered invalid.
• 10.8 Gearbox disassembly: Allow the test machine to cool for 30min–50min (requires confirmation against the source standard (source-text extraction): the original text “30nii n - 5nun” is suspected to be “30min–50min”). Remove the gearbox cover plate and disassemble the gearbox, but do not damage the deposits on the components.

11. Gear cleanliness evaluation

• 11.1 Removal of scoring parts: Take out the copper strip catalyst, test gears, test bearings, and all components inside the gearbox.
• 11.2 Scoring time requirements: Before scoring, the scoring test pieces should be placed at room temperature for at least 1h, and the test pieces should be placed at an angle of 15° to the vertical direction. The cleanliness scoring of the test pieces should be completed within 64h after the end of the test.
• 11.3 Gear sludge evaluation:
  • 11.3.1 On the large and small gears, wipe out an area about 20mm wide along the keyway direction. Score the sludge on each gear surface separately.
  • 11.3.2 The sludge evaluation area on each gear surface does not include the wiped clean area, gear teeth, or the parts in contact with the gasket spacer ring.
  • 11.3.3 According to the different degrees of sludge, subdivide the total evaluation area by area percentage. For scoring details, refer to the CRC NO.12 manual (the manual includes sludge grades and sludge judgment methods). Calculate and record the total sludge amount coefficient for each subdivided area. The total sludge amount coefficient for each tooth surface is obtained by adding the coefficients of each subarea.
  • 11.3.4 Refer to the CRC NO.12 manual. Convert the total coefficient to each tooth surface for evaluation. Report the evaluation result, retaining two decimal places.
  • 11.3.5 The sludge evaluation value is obtained by averaging the sludge evaluation values of the four tooth surfaces.
• 11.4 Gear carbon deposit/varnish evaluation:
  • 11.4.1 The carbon deposit/varnish evaluation is based on the large gear; the evaluation value of the small gear is for reference only. Evaluate the front and back sides of the gear separately. The wiped clean area of each tooth surface is used as the evaluation area, but does not include the gear teeth or the parts in contact with the gasket spacer ring.
  • 11.4.2 Using the CRC NO.14 manual as a guide, divide the tooth surface into areas according to different degrees of carbon deposit and varnish grades. Use the rust/varnish evaluation criteria for non-friction parts in the CRC NO.14 manual to determine the varnish grade of each location where varnish exists.
  • 11.4.3 Carbon deposit degree evaluation: The carbon deposit coefficient ranges from 0.00 (severe carbon deposit) to 0.99 (trace carbon deposit). Observe the carbon deposit thickness, and determine the carbon deposit evaluation coefficient according to Table 1, and describe the carbon deposit condition of each divided area. Calculate the carbon deposit evaluation value by multiplying the carbon deposit evaluation coefficient by the area percentage. Report the result to two decimal places.
  • 11.4.4 Add up the scores of each divided area in the wiped clean area of the tooth surface to determine the carbon deposit/varnish score for the tooth surface.
  • 11.4.5 The carbon deposit/varnish score of the gear is obtained by averaging the scores of the front and back sides of the large gear. For the small gear score, its value is for reference only.
• 11.5 Cleanliness score calculation: Use the scoring table in Appendix C to calculate and report the carbon deposit/varnish and sludge scores.

12. Procedure for determining mass loss of copper strip catalyst

• 12.1 Soak the notched copper strip in aviation washing gasoline for 30min, then clean the oxidation products on the copper strip with absorbent cotton and petroleum ether, finally rinse with petroleum ether, and air dry.
• 12.2 The cleaned copper strip catalyst should be handled with tweezers or filter paper to avoid errors in mass loss calculation. Weigh the marked copper strip catalyst after cleaning, accurate to 0.0001g. Its mass loss is reported as the percentage of original mass loss.

13. Evaluation of oil sample after test

• 13.1 Use the GB/T 11137 test method to determine the 100℃ kinematic viscosity of the sample before and after the test. The sample is not filtered. The viscosity determination of the oil sample after the test should be completed within 48h after the end of the test.
• 13.2 Use the GB/T 7304 test method to determine the total acid number of the sample after the test.
• 13.3 Use the A method in the GB/T 8926 test method to determine the pentane insolubles and toluene insolubles of the sample after the test. The determination should also be completed within 48h after the end of the test. (requires confirmation against the source standard (source-text extraction): the original text here says “GB/T 8426”, but in Chapter 2 normative references it is “GB/T 8926 used lubricating oil insolubles determination method”, suspected to be source-text extraction noise)

9. Qualitative and quantitative and calculation formulas

14.1 Calculation of viscosity increase

Use the initial viscosity and final viscosity of the test oil to calculate the viscosity increase by formula (2).

$$\Delta_v = \frac{V_F - V_I}{V_I} \times 100$$

Where:

• $\Delta_v$ — viscosity increase, %;
• $V_F$ — final kinematic viscosity of the test oil, mm²/s;
• $V_I$ — initial kinematic viscosity of the test oil, mm²/s.

14.2 Calculation of mass loss percentage of copper strip catalyst

Use formula (3) to calculate the mass loss percentage of the copper strip catalyst:

$$W_s = \frac{W_I - W_F}{W_I} \times 100$$

Where:

• $W_s$ — percentage mass loss of the copper strip catalyst, %;
• $W_I$ — initial mass of the copper strip catalyst determined in 8.6.4, g;
• $W_F$ — final mass of the copper strip catalyst determined in 12.1.2, g. (requires confirmation against the source standard (source-text extraction): the original text "12.1.2" is suspected to be "12.2")

14.3 Conversion of Test Results

Convert the test results of reference oils and non-reference oils using the following parameters:

Note: EOT— indicates the end of the test; ln— natural logarithm; CV— carbon deposit and varnish rating value.

14.4 Correction of non-reference oil results shall be carried out according to the formulas in Appendix D, and correction for bench severity shall be carried out according to the formulas in Appendix E.

14.5 Determination of Test Validity

• 14.5.1 The time for the test oil temperature to rise from room temperature to 162.2℃ shall be greater than 45min, but shall not exceed 60min. Tests with a heating time less than 45min or greater than 60min shall be treated as invalid tests.
• 14.5.2 Use formula (4) to calculate the out-of-range percentage for each parameter in Table 2, and record the results in the test report.

$$OUT = \frac{M_i}{0.5R \cdot T_i} \times 100$$

Where:

• OUT — out-of-range percentage;

• $M_i$ — the parameter value that is out of range at i;

• R — the specified range of the test parameter;

• $T_i$ — the number of times the test parameter is out of range at i;

• θ — heating or test segment time, in the same unit as $T_i$.

• 14.5.3 If the out-of-range percentage calculated for each parameter during the heating stage and the test stage is greater than the range specified in Table 2, the test shall be considered invalid.

Table 2 Test Parameter Validity Requirements

Table 1 Carbon Deposit Degree Evaluation Indicators

10. Precision

Judge the reliability of test results according to the 95% confidence level.

16.1 Precision

• 16.1.1 Repeatability (r): the difference between two test results obtained by the same operator using the same instrument under the same operating conditions for continuous determination of the same sample shall not exceed the value in Table 3.
• 16.1.2 Reproducibility (R): the difference between two test results obtained by different operators in different laboratories for continuous determination of the same sample shall not exceed the value in Table 3.

Table 3 Precision Data for Reference Oil Tests

Note: These statistics are based on TMC reference oils 131-3, 131-4, 143 and 148, where: $S_r$—repeatability standard deviation; $r$—repeatability; $S_R$—reproducibility standard deviation; $R$—reproducibility.

16.2 Bias

Bias is determined by an accepted stable reference oil result. When a valid bias is determined, strict adjustment of non-reference oil test results is permitted (see Appendix D and Appendix E).

11. Report

• 15.1 Issue a standard test report as shown in Appendix C.
  • 15.1.1 Viscosity increase (%), non-reference oil tests shall be corrected according to Appendix D and Appendix E.
  • 15.1.2 Pentane insolubles % (mass fraction), non-reference oil tests shall be corrected according to Appendix D and Appendix E.
  • 15.1.3 Toluene insolubles % (mass fraction), non-reference oil tests shall be corrected according to Appendix D and Appendix E.
  • 15.1.4 Average varnish/carbon deposit, non-reference oil tests shall be corrected according to Appendix D and Appendix E.
  • 15.1.5 Average sludge, non-reference oil tests shall be corrected according to Appendix D and Appendix E.
• 15.2 Test report attachments: attach photographs of the gears, bearings, and copper strip catalyst and the test temperature curve chart to the test report.

Appendix C gives the L-60-1 test pass criteria:

• Viscosity increase/% < 100
• Pentane insolubles/% (mass fraction) < 3.0
• Toluene insolubles/% (mass fraction) < 2.0
• Average varnish/carbon deposit > 7.5
• Average sludge > 9.4

12. Normative References

• GB/T 4830 Industrial automation instrument air source pressure range and quality
• GB/T 7304 Determination of acid number of petroleum products and lubricants (potentiometric titration method)
• GB/T 8926 Determination of insolubles in used lubricating oils
• GB/T 11137 Determination of kinematic viscosity of dark petroleum products (reverse flow method) and calculation of dynamic viscosity
• GB/T 15894 Chemical reagent petroleum ether
• SH 0114 Aviation washing gasoline

13. Source and verification

This page is an AI translation of the available Chinese method card. Human verification is pending. It is not an official translation of the standard. Check the source standard and product certificate before use.

14. Quick Reference Q&A