SH/T 0751-2005 Determination of viscosity at high temperature and high shear rate (tapered plug viscometer method)

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Card type: Test method

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

• Standard number: SH/T 0751-2005
• Chinese full name: Determination of viscosity at high temperature and high shear rate (tapered plug viscometer method)
• English name: Standard test method for measuring viscosity at high temperature and high shear rate by tapered-plug viscometer
• Replacement relationship: not provided in the available source (no mention of replacing any old standard)
• Adoption relationship: modified adoption of ASTM D4741-00 "Determination of viscosity at high temperature and high shear rate (tapered plug viscometer method)"
• Publication/implementation: published by 2005-04-11 (the source source-text extraction is "2005-04-1, published", the last digit of the date requires confirmation against the source standard (source-text extraction)), implemented on 2005-09-01
• Publishing body: National Development and Reform Commission of the People's Republic of China
• Secretariat: Sinopec Research Institute of Petroleum Processing
• Drafting unit: Sinopec Lubricant Shanghai Branch
• Main drafters: Wang Yaping, Yang Shuhong, Zhu Xiaoyi

2. Scope of application and non-applicability

• 1.1 This standard specifies the determination of the viscosity of lubricating oils in the laboratory using a high shear rate tapered plug viscometer of model BE/C (single speed) or BS/C (multi-speed), under conditions of 150℃ and 1×10⁶ s⁻¹ and 100℃ and 1×10⁶ s⁻¹.
• 1.2 Newtonian calibration oils may be used to adjust the working gap and calibrate the instrument; the viscosity range of the calibration oils at 150℃ is approximately 1.8 mPa·s to 5.9 mPa·s, and at 100℃ is approximately 4.2 mPa·s to 18.9 mPa·s. Calibration oils outside this viscosity range shall not be used, otherwise the precision of this method no longer applies.
• 1.3 This standard specifies the use of non-Newtonian check oils to verify the reliability of the test conditions; the exact viscosity of each batch of check oil is established by testing on multiple instruments in different laboratories. The exact viscosity value of the check oil can be obtained from the chairman of the European Coordinating Committee (CEC) L-36-AA supervisory group or from the oil supplier.
• 1.4 This standard is applicable to the testing of internal combustion engine oils.
• 1.5 This standard uses mPa·s as the viscosity unit.
• 1.6 This standard does not include all safety matters that may be involved during use; users should establish appropriate safety and protective measures and determine applicable management systems before using this standard.
• Non-applicability: not provided in the available source as an independent clause on "non-applicability"; only the following are seen: 1.2 precision no longer applies when calibration oil is out of range, 8.2 no precision specification for used oils, 8.2.1 note "this standard does not expect or attempt to test such oil samples" (referring to oil samples containing particulate focal matter larger than 3 μm).

3. Method principle

• 4 Method summary: The sample is introduced between the rotor and stator in a fixed spherical sleeve. The rotor and stator are fitted with a cone to adjust the gap between them and thereby adjust the shear rate. The rotor rotates at a given rate, and the resulting reaction torque is measured. From the torque value, the viscosity of the sample is determined from a standard curve obtained with Newtonian calibration oils.
• 5 Significance and use:
  • 5.1 The viscosity measured under the conditions of this test has a certain correspondence with bearing temperature and shear rate under internal combustion engine operating conditions, but is independent of pressure.
  • 5.2 The test conditions for internal combustion engine oil viscosity have been discussed in many publications.

4. Reagents and materials (purity / preparation)

• 7.1 Newtonian calibration oils: RL102, RL103, RL104, RL105, RL106 and RL107.
• 7.2 Non-Newtonian check oil: RL174.
• 7.3 Cleaning solvent: meets the requirements in SH/T 0024 Annex A or an equivalent solvent.
• 7.4 Flushing agent: solvent oil meeting the requirements of No. 3 in GB 1922.
• Purity and specific preparation method: not provided in the available source.

5. Apparatus and equipment

• 6.1 Rotor. Note: Because the torque of the BE/C viscometer has a certain limited range, testing under the condition of 100℃ cannot be performed.
• 6.2 High shear tapered plug viscometer: model BE/C or BS/C. This viscometer uses a rotating rotor in a matching measuring chamber.
• 6.3 Vacuum pipette: can maintain the test oil at a certain liquid level height, suitable for all existing instruments.
• 6.4 Calibration weights (provided with the instrument).
• 6.5 Constant-temperature bath: with a circulation device; to ensure sufficient test temperature, the temperature difference between the constant-temperature bath and the test head is set to 4℃, and the maximum must not exceed 8℃. This temperature difference is affected by ambient temperature, flow rate of the constant-temperature bath liquid, length and inner diameter of the heating line, and viscosity of the constant-temperature bath liquid. Note: The kinematic viscosity of the constant-temperature bath liquid at 150℃ is not greater than 10⁻⁶ m²/s (the source source-text extraction is "10- 1/s", unit requires confirmation against the source standard (source-text extraction)).
• 6.6 Since the instrument is already equipped with a more precise temperature sensor, no additional temperature measurement equipment is needed. If an older model instrument is still used, temperature measurement equipment with a measurement error requirement within ±0.20℃ must be provided.
• 6.7 Ultrasonic cleaner (recommended).
• 6.8 The manufacturer provides a complete set of instruments, including all the above equipment as well as necessary calibration oils, check oils and constant-temperature bath liquid.
• 6.9 Vacuum pump: equipped with a liquid trap.

6. Recommended operating conditions

• Test temperature: 150℃ and 100℃.
• Shear rate: 1×10⁶ s⁻¹.
• 10.1.9 Start reading when the temperature display changes from 149.9℃ to 150.0℃ or from 99.9℃ to 100.0℃. This is automatic on model BS/C and manual on other models. During manual operation, the heating rate must not be greater than 0.1℃/s (the source source-text extraction is "4s must not be greater than 0.19C(0.0250C/s)", requires confirmation against the source standard (source-text extraction)). For automatic models, the maximum allowable heating rate is 0.07℃/s.
• 10.1.10 There is no maximum specified for the time required for the test temperature to rise from 149.9℃ to 150.0℃ or from 99.9℃ to 100.0℃, but if this process exceeds 8s or 10s, the test precision may be reduced.
• 10.2.3 When the viscosity of the injected sample is completely different from that of the previous injection (e.g., RL102 injected after RL106), use four full funnel sample amounts. In other cases, use two full funnel sample amounts. One full funnel sample amount is approximately 10 mL.
• 10.2.4 In all repeatability tests, one full funnel sample amount is sufficient. Note: During repeatability tests, ensure that the sample does not contain bubbles after passing through the funnel, so as to allow the temperature to decrease.
• 10.2.5 Before testing, the test temperature decrease must not be less than 1℃.
• 10.3.1 First, the operating gap between the rotor and stator must be adjusted so that the shear rate during the test reaches 1×10⁶ s⁻¹.
• 10.3.2 Using calibration oil RL106, adjust to the appropriate torque according to the instructions in the instrument manual.
• 10.1.6 When the correlation coefficient meets the requirements, test with non-Newtonian check oil. Thereafter, after every 3 to 6 sample tests, verify with non-Newtonian check oil.
• 11.3 After every 6 samples tested, verification with non-Newtonian check oil is required.

7. Sampling and sample preparation

• 8.1 If the test oil is visually free of turbidity and particulate matter, filtration before testing is not required. If the largest particles in the oil are larger than 3 μm, the test oil needs to be passed through a filter with a pore size of 3 μm; if there are still many small particles, it may be filtered again, which can reduce the possibility of particles becoming embedded in the instrument gap and avoid contamination of the measuring chamber or erroneous results. To avoid filtering out lubricant additives, a filter smaller than 1 μm must not be used (the source source-text extraction is "a filter smaller than 11 un must not be used", requires confirmation against the source standard (source-text extraction)).
• 8.2 Used oils may also be tested by this standard, but no precision specification is provided.
• 8.2.1 Used oils may be filtered using a suitable filter, for example Whatman GF/C glass fiber filter. During filtration, heating or pressurization may be used to increase the filtration speed, and contamination by fine particles must be prevented during this process. Note: If the oil sample contains focal matter composed of particles larger than 3 μm, the filtration process will cause a change in viscosity, and this standard does not expect or attempt to test such oil samples. A large amount of evidence shows that for engine oils that have been in normal use for a period of time, filtration may be performed first, but pressure filtration is recommended rather than vacuum filtration, so as to avoid loss of volatile components in the sample. However, this standard still has no precision specification for used oils.

8. Analytical procedure

• 9 Preparation work:
  • 9.1 BE/C and BS/C tapered plug viscometers are controlled by computer. A vacuum pipette is used to ensure the liquid level of the oil.
  • 9.2 Install the instrument according to the instructions provided by the instrument manufacturer, and attach the funnel to the side arm of the instrument with a rubber tube. Note: The tube diameter of this funnel should be larger than the inlet of the side arm, so as to increase the flow rate of the oil sample.
  • 9.3 To prevent dust contamination, the instrument must not be operated in a fume hood. Since the constant-temperature bath provided by the instrument manufacturer is almost sealed, the suction filtration tube should be placed above the constant-temperature bath.
  • 9.4 When debugging the instrument, make a calibration curve according to the instructions provided by the instrument manufacturer.
  • 9.5 The manufacturer has already set all functions and zero adjustment when the instrument leaves the factory, so it is recommended not to modify the initial factory settings before fully understanding the instrument performance. If modification is definitely needed, detailed instructions are provided in the instrument manual.
  • 9.6 Retrieve the calibration oil list stored in the instrument to become familiar with its contents and check whether it conforms to the provided standard.
  • 9.7 Instrument preparation under other circumstances:
    • 9.7.1 Turn on the constant-temperature bath switch, and rinse the measuring chamber with cleaning solvent.
    • 9.7.2 Fill the measuring chamber with the check oil RL174.
    • 9.7.3 Wait at least half an hour for the temperature of the constant-temperature bath liquid to stabilize.
    • 9.7.3.1 If the constant-temperature bath liquid does not reach the set temperature within this time, the heating time may be extended or the cause of the excessively long heating time may be sought.
• 10 Test procedure:
  • 10.1 Overview:
    • 10.1.1 Inject the sample onto an annular surface located between the rotor and the stator; the rotor and stator have a suitable taper, and the shear rate is adjusted by adjusting their gap. The rotor rotates at a given rate, and the resulting torque value is compared with a calibration curve made using Newtonian calibration oils to obtain the viscosity of the sample.
    • 10.1.2 Use Newtonian calibration oils to check the working gap and calibrate the instrument; the viscosity range of these calibration oils at 150℃ is approximately 1.8 mPa·s to 5.9 mPa·s, and at 100℃ the viscosity range is approximately 4.2 mPa·s to 18.9 mPa·s. Calibration oils outside this viscosity range shall not be used (see 1.1).
    • 10.1.3 Non-Newtonian check oils are used to verify the reliability of the test conditions; the exact viscosity value of the check oil can be obtained from the chairman of the European Coordination Committee (CEC) SLA-36 supervisory group (using method L-36) or from the oil supplier.
    • 10.1.4 Use the torque values of 6 Newtonian calibration oils to plot a calibration curve against viscosity values, and perform a linear regression on this curve; it should be a straight line passing through the origin.
    • 10.1.5 The definition of the correlation coefficient is given in Appendix A; the correlation coefficient must be accurate to five decimal places and shall not be less than 0.99970. The torque deviation can well characterize the operating state of the rotor and stator during operation, and it can also serve as a reference for laboratory quality control.
    • 10.1.6 When the correlation coefficient meets the requirements, test with the non-Newtonian check oil. Thereafter, after every 3 to 6 samples tested, verification with the non-Newtonian check oil shall be carried out to ensure the accuracy of the test results.
    • 10.1.7 Initially, the deviation between the measured value of the check oil and the value given by the instrument manufacturer shall be within the following ranges: at a temperature of 150℃, the deviation is ±0.04 mPa·s; at a temperature of 100℃, the deviation is ±0.06 mPa·s. Subsequently, the deviation between the measured value of the check oil and the value given by the instrument manufacturer shall be within the range of ±0.06 mPa·s, provided that the direction of the deviation of the check oil is the same as the direction of the initial test deviation.
    • 10.1.8 If at any time the test result of the check oil is found to exceed the above-specified range, all data tested after the last acceptable inspection shall be discarded, and these samples shall be retested.
    • 10.1.9 Start reading when the temperature display changes from 149.9℃ to 150.0℃ or from 99.9℃ to 100.0℃. This is automatic on model BS/C and manual on other models. For manual operation, the heating rate shall not be greater than 0.1℃/s (requires confirmation against the source standard (source-text extraction)). For automatic models, the heating rate may be allowed up to 0.07℃/s.
    • 10.1.10 There is no specified maximum time required for the test temperature to rise from 149.9℃ to 150.0℃ or from 99.9℃ to 100.0℃, but if this process exceeds 8s or 10s, the accuracy of the test may be reduced.
    • 10.1.11 Test one sample at least twice. If the difference between the two test data exceeds 1%, a third or even fourth repeat test is required. This situation mainly occurs because the previously tested sample was not rinsed clean. Re-rinsing before measurement helps to obtain accurate results more quickly.
  • 10.2 Sample introduction:
    • 10.2.1 During sample introduction, whether introducing calibration oil or sample, use the funnel on the side arm for introduction, then recover through the vacuum tube and discard.
    • 10.2.2 Fill the funnel with the oil sample; the oil sample slowly flows from the bottom of the side arm into the measuring chamber; repeat this process one or more times.
    • 10.2.3 When the viscosity of the sample introduced is completely different from that of the previous sample (e.g., RL102 introduced after RL106), use four full funnels of sample. In other cases, use two full funnels of sample. One full funnel of sample is approximately 10 mL.
    • 10.2.4 In all repeatability tests, one full funnel of sample is sufficient. Note: When performing repeatability tests, ensure that the sample does not contain bubbles after passing through the funnel, so as to allow the temperature to decrease.
    • 10.2.5 Before testing, the test temperature drop shall not be less than 1℃.
  • 10.3 Setting the shear rate:
    • 10.3.1 First, the operating gap between the rotor and stator must be adjusted so that the shear rate during the test reaches 1×10⁶ s⁻¹.
    • 10.3.2 Using calibration oil RL106, adjust to the appropriate torque according to the instructions in the instrument manual.
    • 10.3.3 When the temperature rises from 149.9℃ to 150.0℃ or from 99.9℃ to 100.0℃, if the theoretical torque is consistent with the torque calculated from the current depth recorded on the scale, perform step 10.4. After adjustment with non-Newtonian check oil, this may no longer be correct. Note: This significant difference may be caused by a deviation in the torque measurement system or by metal friction between the rotor and stator.
  • 10.4 Establishing the calibration curve:
    • 10.4.1 Use 6 Newtonian calibration oils to establish a calibration curve of viscosity values versus torque values; this can be used for linear regression to meet the requirements in 10.1.5.
    • 10.4.2 Test RL102 at least twice to obtain the results described in 10.1.11. Test oil samples RL103 to RL107 in order of increasing viscosity, repeat test RL106, and establish the calibration curve as described in 10.1.4 and 10.1.5.
  • 10.5 Use non-Newtonian check oil to test its viscosity value:
    • 10.5.1 The results of the check oil must meet the requirements in 10.1.7. Otherwise, adjust according to the instrument instructions, then repeat clauses 10.4 and 10.5.
    • 10.5.2 Only when both the check oil test results and the correlation coefficient meet the requirements may the test be carried out.
• 11 Test process:
  • 11.1 Add the sample as described in clause 10.2, record the torque reading as described in 10.1.9, and repeat the test at least once as described in 10.1.11.
  • 11.2 Obtain the viscosity of the sample from the viscosity-torque calibration curve in clause 10.4.
  • 11.3 After every 6 samples tested, verification with non-Newtonian check oil must be carried out.

9. Qualitative and quantitative and calculation formulas

• 11.2 Obtain the viscosity of the sample from the viscosity-torque calibration curve in clause 10.4.
• Appendix A (informative appendix) Definition of the correlation coefficient: different methods define the correlation coefficient. The correlation coefficient applicable to this method is defined by the following formula:

r = [M·Σxiyi − (Σxi)(Σyi)] / { √[M·Σxi² − (Σxi)²] · √[M·Σyi² − (Σyi)²] } …………（A-1）

Where:

• M —— represents the number of data points;
• x, y —— respectively represent the measured data of two variables.

This formula has been stored in the computer connected to the instrument. (The original formula source-text extraction has noise; the symbols are subject to the above arrangement, requires confirmation against the source standard (source-text extraction))

10. Precision

• 14.1 Precision: The reliability of test results is judged according to the following provisions (95% confidence level).
• 14.1.1 Repeatability (r): For measurements of the same sample by the same operator using the same instrument, the difference between the two results obtained shall not exceed 1.7% of the mean under the test conditions of 150℃, and shall not exceed 1.0% of the mean under the test conditions of 100℃. This repeatability result is valid only for viscosity ranges approximately 2.6 mPa·s to 4.7 mPa·s at 150℃, and approximately 4.9 mPa·s to 11.8 mPa·s at 100℃.
• 14.1.2 Reproducibility (R): For measurements of the same sample by different operators in different laboratories according to the same test method, the difference between the two results obtained shall not exceed 2.6% of the mean under the test conditions of 150℃, and shall not exceed 2.4% of the mean under the test conditions of 100℃. The reproducibility result is valid only for viscosity ranges approximately 2.6 mPa·s to 4.7 mPa·s at 150℃, and approximately 4.9 mPa·s to 11.8 mPa·s at 100℃.
• 14.2 The data at 150℃ in 14.1.1 and 14.1.2 are results obtained after statistics from 12 non-Newtonian test oils in 9 laboratories (a total of 432 results). These test oil series with viscosity ranges at 150℃ and 1×10⁶ s⁻¹ of 2.5 mPa·s to 4.8 mPa·s include oil samples of grades SAE 5W-30, 5W-30, 10W-30, 10W-40, 15W-50 (the original text source-text extraction is “SAFAW[unreadable separator]30, 5W[unreadable separator]30, IOW[unreadable separator]30, 10W[unreadable separator]40, 15W[unreadable separator]50”, requires confirmation against the source standard (source-text extraction)).
• The data in 14.3 under 100℃ in 14.1.1 and 14.1.2 are results obtained after statistics from 12 kinds of non-Newtonian test oils in 7 laboratories (a total of 126 results). These test oil sample series with viscosity ranges under 100℃ and 1×10⁶ s⁻¹ of 4.9 mPa·s～11.8 mPa·s include oil samples of grades SAE 0W-10, 5W-30, 15W-40, 20W-40, 20W-50, 25W-30, 30 and 40 (the original text source-text extraction is “SAFAW[unreadable separator]10, 5W[unreadable separator]30, 15W[unreadable separator]40, 20W[unreadable separator]40, 20W[unreadable separator]50, 25W[unreadable separator]30, 30 and 40”, requires confirmation against the source standard (source-text extraction)).
• 14.4 bias: the bias of this test method is less than 0.06 mPa·s, which can be ensured by performing periodic check oil verification.
• 14.5 relative bias: this standard, through interlaboratory testing, demonstrates that its results are consistent with the test results of ASTM D4683 at 100℃ and 150℃. In the long run, using the above two methods to determine the same test oil can yield the same high-temperature high-shear viscosity value.
• 13 method evaluation: the evaluation of this standard is determined by observing the test data and correlation coefficients of standard oils, and is frequently verified with check oils.

11. Report

• 12.1 Record the viscosity under high-temperature high-shear conditions at 150℃ and 1×10⁶ s⁻¹ or 100℃ and 1×10⁶ s⁻¹, in units of mPa·s.
• 12.2 The viscosity value is accurate to two decimal places and follows the rounding principle.

12. Normative references

• GB 1922 Solvent naphtha for paints and cleaning
• SH/T 0024 Determination of precipitation number of lubricating oils
• ASTM D4683 Determination of viscosity at high temperature and high shear rate (tapered plug bearing simulation method)
• ASTM D4741-00 Determination of viscosity at high temperature and high shear rate (tapered plug viscometer method) (the original standard modified and adopted by this standard)

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 Q&A reference