NB/SH/T 0912-2015 Engine bench test oil 100℃ kinematic viscosity determination method

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Card type: Test method

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

• Standard number: NB/SH/T 0912—2015
• Chinese full name: Engine bench test oil 100℃ kinematic viscosity determination method
• English name: Standard test method for determination of kinematic viscosity at 100°C of engine test oils
• Replacement relationship: First release; modified adoption by redrafting method of CEC L-83-97 "Determination of kinematic viscosity of in-service oil 100°"
• Technical differences from CEC L-83-97 (original foreword):
  • The standard name is changed to "Engine bench test oil 100℃ kinematic viscosity determination method"
  • In Chapter 5 instruments, the capillary viscometer types are increased to include Fenske reverse-flow viscometers meeting the requirements of ISO 3105 or ASTM D446 or SH/T 0173—1992
  • Delete content related to CEC L-56-T-98
  • Delete referenced standards ISO/IEC 17025 and ISO 5725
  • Delete relevant statements concerning measurement uncertainty
  • Add warning information for toluene, acetone and chromic acid cleaning solution
  • Delete relevant data and charts from the analysis of international interlaboratory test results in the precision chapter
  • Make editorial modifications according to China's standard drafting format; for structural differences see Appendix A
• Publication/implementation: Published on 2015-10-27, implemented on 2016-03-01; issued by the National Energy Administration
• Secretariat: Subcommittee on Lubricating Oil Drain Intervals of the National Technical Committee for Standardization of Petroleum Products and Lubricants (SAC/TC280/SC6)
• Drafting organization: Dalian Lubricating Oil Research and Development Center of PetroChina Company Limited
• Main drafters: Xie Pingping, Pang Cuicui

2. Scope of application and non-applicability

• This standard specifies the method for determining the kinematic viscosity of in-service oil 100℃ using a Fenske reverse-flow capillary viscometer.
• This standard applies to the determination of kinematic viscosity of engine bench test oil 100℃ containing soot.
• Not applicable: no explicit non-applicability clause is provided in the available source.

3. Method principle

After thoroughly mixing the in-service oil sample, under strictly controlled temperature, measure the time for the sample to flow through a Fenske reverse-flow viscometer under gravity; the product of the flow time and the viscometer constant is the kinematic viscosity of the sample 100℃.

4. Reagents and materials (purity / preparation)

• 5.1 Cleaning solvents
  • 5.1.1 Sample solvent: capable of completely mixing with the sample, such as solvent naphtha, toluene, etc.
    • Warning: Toluene, highly flammable, its vapor is harmful if inhaled, and it can react violently with oxidants. Avoid contact with eyes during use, keep away from ignition sources, take anti-static measures and store sealed.
  • 5.1.2 Drying solvent: acetone.
    • Warning: Acetone, highly flammable, toxic and harmful if inhaled or ingested.
  • 5.1.3 Cleaning solution: chromic acid cleaning solution.
    • Warning: Chromic acid is toxic/harmful to health, is a recognized carcinogen, is strongly corrosive, and has potential hazards to organic tissues. Wear a protective face shield, long protective clothing, and suitable gloves during use. The acid will volatilize into vapor. Used chromic acid should be handled with great care when exposed to air because it remains toxic; avoid inhaling vapor.
• 5.2 Materials: the original source-text extraction shows "5.2 material" "5.2 60 mLo", suspected to be "60 mL plastic bottle" etc., requires confirmation against the source standard (source-text extraction).
• Purity and specific preparation methods: not provided in the available source.

5. Instruments and equipment

• 4.1 Constant-temperature bath: use a transparent liquid as the medium, and it shall have sufficient depth so that throughout the entire measurement process, the constant-temperature bath liquid level is at least 20 mm above the sample liquid level in the viscometer, and the bottom of the viscometer is at least 20 mm above the bottom of the constant-temperature bath. The difference between the constant-temperature bath medium temperature and the set temperature shall not exceed ±0.02℃, and it shall be calibrated and qualified.
• 4.2 Cannon-Fenske reverse-flow capillary viscometer, size designation 200, or other Fenske reverse-flow capillary viscometers meeting the requirements of ISO 3105 or ASTM D446 or SH/T 0173—1992, subject to periodic verification and determination of the viscometer constant in accordance with ISO 3105 or ASTM D446. The capillary viscometer may also be calibrated and verified in accordance with the national metrological verification regulation JJG 155.
• 4.3 Timer, accurate to 0.1 s or better, with a reading precision within ±0.07% when the test time reaches 15 min. The accuracy of the timing device can be confirmed by a standard time signal. It may be used only after calibration is qualified.
• 4.4 Temperature measuring device, used to measure the temperature of the constant-temperature bath; it may be used only after calibration is qualified.
• 4.5 Paint shaker or mechanical oscillator, optional, used to homogenize the sample.

6. Recommended operating conditions

• Constant-temperature bath temperature: 100℃ (see 7.4).
• Constant-temperature bath temperature fluctuation: the difference from the set temperature shall not exceed ±0.02℃ (see 4.1).
• Viscometer constant-temperature time: 15 min±30 s (see 7.4).
• Other operating conditions: not provided in the available source.

7. Sampling and sample preparation

• 6.1 The kinematic viscosity test of in-service engine oil 100℃ shall be completed within one month after the engine test is finished; test results beyond this period are invalid, and research test samples are not subject to this restriction. The result report provided to the customer shall indicate the test time.
• 6.2 The sample is stored at room temperature and shall be mixed uniformly before testing. Use a 60 mL plastic bottle to contain the sample, and keep an appropriate distance between the upper liquid level of the sample and the top of the container, recommended not less than 1 cm, to avoid excessive air entrainment in the sample during shaking.
• 6.3 The in-service engine oil sample shall be mixed uniformly before sampling and testing; it may be shaken by hand for about 1 min, and a mechanical oscillator or paint shaker is recommended. The completion from uniform sample mixing to filling the capillary viscometer shall be within 2 min±1 min. If a paint shaker is used, it is recommended to mix the in-service oil sample uniformly by the following method; the spring supporting the shaker shall be able to simultaneously provide vertical motion of the sample.
  • 6.3.1 Tighten the lid of the sample container.
  • 6.3.2 Place the sample container on the paint shaker.
  • 6.3.3 Shake for 5 min±15 s.
  • 6.3.4 Remove the sample container from the paint shaker.
  • 6.3.5 Perform the test.
• Note: Sampling... heating or filtering the sample (the original source-text extraction is incomplete, requires confirmation against the source standard (source-text extraction)).

8. Analysis procedure

• 7.1 Prepare two viscometers, immerse them in the sample, and draw through the suction tube N (see Figure A). Fill the bulb D through tube L with sample until it exceeds the mark line G 5 mm.
• 7.2 Invert the viscometer to normal... wipe off excess sample with a clean cloth (the original source-text extraction is incomplete, requires confirmation against the source standard (source-text extraction)).
• 7.3 Connect the end of suction tube N to a vacuum pump, and draw the sample to 3/4 of the length of capillary B (see Figure 1). Plug the end of tube L with a rubber stopper to prevent the sample from flowing in the tube. If the sample flows to the first timing mark E before testing, the test result is invalid.
• 7.4 Place the viscometer in a 100℃ constant-temperature bath; the constant-temperature bath liquid level shall be above bulb D, and keep tube L vertical. The viscometer constant-temperature time is 15 min±30 s, including the sample flowing to within 2 mm of point E; therefore, the rubber stopper shall be removed at the appropriate time to ensure the sample flows to the specified position within the specified time.
• 7.5 Remove the rubber stopper; the sample flows naturally; when it reaches the first timing point E, immediately start the timer (see Figure 3).
• 7.6 After the sample reaches the second timing point F, immediately stop the timer (see Figure 4), and record the time for the sample to flow from the first timing point E to the second timing point F (accurate to 0.1 s).
• 8 Clean the viscometer
  • 8.1 After the test is completed, blow out the sample under pressure, or extract the sample with a vacuum pump.
  • 8.2 Use a sample solvent capable of completely dissolving the sample to repeatedly and thoroughly clean the viscometer, then rinse the viscometer with a drying solvent (see 6.1.2, suspected to be 5.1.2, requires confirmation against the source standard (source-text extraction)).
  • 8.3 Slowly pass a stream of dry air through and blow-dry the viscometer.
  • Note: If necessary, the viscometer may be cleaned with chromic acid cleaning solution.

9. Qualitative and quantitative determination and calculation formula

• 9.1 Kinematic viscosity is calculated from the sample flow time and the viscometer constant according to the following formula:
  • ν = C·t
• 9.2 Where:
  • ν—— kinematic viscosity, in square millimeters per second (mm²/s);
  • C—— viscometer constant, in square millimeters per square second (mm²/s²);
  • t—— flow time of the sample, in seconds (s).
• The average of the two determination results is taken as the kinematic viscosity of the sample 100℃.

10. Precision

• The precision of this method was determined through statistical analysis of international interlaboratory test results from 2007 to 2011. The determination of this precision selected only a portion of in-service oil types when selecting test oils, and is based on a small amount of data; therefore, it may differ for other sample oils with different formulation compositions or different degrees of degradation, and may also differ for test oils of different viscosity grades or different soot contents. The precision data of this standard apply to in-service engine oil samples with kinematic viscosity 100℃ in the range of 12 mm²/s to 43 mm²/s; the precision of samples outside this viscosity range has not been verified. Judge the reliability of test results according to the following provisions (95% confidence level).
• 12.1 Repeatability (r): For the same operator, using the same instrument, under the same experimental conditions, the difference between two repeated determination results on the same sample shall not be greater than the value in Table 1.
  • Table 1 Repeatability
    • Viscosity range/(mm²/s): 12~43
    • Repeatability/(mm²/s): 0.0322×e^(0.086r) (the source text source-text extraction is as such, the exponent part is suspected to be erroneous, requires confirmation against the source standard (source-text extraction))
    • Note: X is the arithmetic mean of the two replicate test results being compared, mm²/s.
• 12.2 Reproducibility (R): the difference between two independent results obtained by different operators in different laboratories on the same sample shall not exceed the value in Table 2.
  • Table 2 Reproducibility
    • Viscosity range/(mm²/s): 12~43
    • Reproducibility/(mm²/s): 0.0349×e^(0.1327) (the source text source-text extraction is as such, a variable is suspected to be missing, requires confirmation against the source standard (source-text extraction))
    • Note: X is the arithmetic mean of the two single independent test results being compared, mm²/s.

11. Report

The report shall include the following information:

• Reference to this standard;
• Identification of the test sample;
• 100℃ kinematic viscosity, expressed in mm²/s, with the result retained to the 2th decimal place;
• Test date.

12. Normative references

• JJG 155 Verification regulation for working capillary viscometers
• SH/T 0173—1992 Technical specifications for glass capillary viscometers
• ASTM D446 Standard specifications and operating instructions for glass capillary kinematic viscometers
• ISO 3105 Glass capillary kinematic viscometers—Specifications and operating instructions
• GB/T 1.1—2009 (mentioned in the foreword, as the basis for drafting rules)

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