NB/SH/T 0867-2013 Determination of soot content in diesel engine oils — Thermogravimetric analysis method

AI-translated method card — human verification pending. This is not an official translation of the standard. Unclear source values remain unverified; check the original standard and product certificate before use.

Card type: Test method

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

• Standard number: NB/SH/T 0867—2013
• Chinese full title: Determination of soot content in diesel engine oils — Thermogravimetric analysis method
• English title: Standard test method for determination of soot in diesel engine oils by thermal gravimetric analyzer
• Replacement relationship: not provided in the available source (the foreword does not mention replacement of any standard)
• Publication/implementation: published on 2013-06-08, implemented on 2013-10-01
• Issuing authority: National Energy Administration
• Drafting rules: drafted in accordance with GB/T 1.1—2009
• Reference document: ASTM D5967-10a “Standard Test Method for Evaluating Diesel Engine Oils with T-8 Diesel Engines”, Appendix A4 “Thermogravimetric Analysis Procedure”
• Technical committee: National Technical Committee for Standardization of Petroleum Products and Lubricants, Subcommittee on Petroleum Fuels and Lubricants (SAC/TC280/SC1)
• Drafting organizations: Lanzhou Lubricating Oil Research and Development Center and Dalian Lubricating Oil Research and Development Center of PetroChina Company Limited
• Main drafters: Li Jin, Tang Youyun, Li Jianqun, Lu Qinying

2. Scope of application and non-applicability

• Scope of application: This standard specifies a method for measuring the soot content of diesel engine oils by thermogravimetric analysis; it is applicable to the analysis of soot content in various diesel engine oil bench test samples and various in-service diesel engine oils.
• Non-applicability: not provided in the available source.

3. Method principle

The thermogravimetric analyzer operates under a preset program. The sample is first rapidly heated under a high-purity nitrogen atmosphere to volatilize the base oil and additives in the sample, then the soot is burned under the action of high-purity oxygen, and finally ash remains. The soot content in the sample is calculated from the mass loss due to soot combustion. (Chapter 4)

Terms and definitions (Chapter 3):

• 3.1 Soot soot: a highly carbonaceous substance produced during the combustion process of a diesel engine, mainly a product of incomplete combustion of hydrocarbon substances.
• 3.2 Soot content soot content: under the conditions specified in this method, the difference in mass fraction between the two mass-loss plateaus formed by a diesel engine oil sample before and after switching the gas atmosphere (before and after 650℃).

4. Reagents and materials (purity / preparation)

6.1 Reagents

• 6.1.1 Nitrogen: purity 99% (volume fraction) [the text at this point in the source has source-text extraction noise; the purity value requires confirmation against the source standard (source-text extraction)]
• 6.1.2 Oxygen: purity 99% (volume fraction) [the text at this point in the source has source-text extraction noise; the purity value requires confirmation against the source standard (source-text extraction)]
• 6.1.3 Dilute hydrochloric acid (volume ratio 1:1)
• 6.1.4 Distilled water: meets the requirements for grade three water in GB/T 6682—2008

6.2 Materials

• 6.2.1 Crucible (the source transcription is unclear; verify the crucible material and specification against the original standard)
• 6.2.2 Tweezers, copper tweezers (the instrument names are unclear in the source transcription and require verification)
• 6.2.3 Stainless steel scraper

5. Instruments and equipment

• 5.1 Thermogravimetric analyzer: composed of a thermobalance and a data acquisition system; the furnace heating rate is required to reach 100℃/min; it has two gas channels that can be switched automatically.
• 5.2 Data acquisition system: a data acquisition system and data analysis software matched to the thermogravimetric analyzer.
• 5.3 Air compressor (optional equipment).
• 5.4 Oscillator: a speed-adjustable timed oscillator capable of being adjusted to a frequency of 50 Hz and a rotational speed of 720 r/min.

6. Recommended operating conditions

• Gas flow rate (typical operating conditions, clause 8.7):
  • Vertical thermogravimetric analyzer: specific value not provided in the available source (source-text extraction missing)
  • Horizontal thermogravimetric analyzer: sample chamber flow rate 34 mL/min
  • Note: The gas flow rates given in this standard are typical operating conditions; for other instrument models, refer to the instrument manufacturer's instructions.
• Thermogravimetric analysis program (Chapter 9):
  • 9.1 The sample chamber of the thermogravimetric analyzer is under nitrogen [the source transcription gives nitrogen, but the complete atmosphere condition requires verification]
  • 9.2 After holding at constant temperature 50℃ for 1 min, heat to 550℃ at a heating rate of 100℃/min
  • 9.3 Hold at constant temperature 550℃ for 1 min
  • 9.4 After holding at constant temperature 550℃ for 1 min, heat to 650℃ at a heating rate of 20℃/min
  • 9.5 Hold at constant temperature 650℃ for 1 min
  • 9.6 After holding at constant temperature 650℃ for 1 min, switch the sample chamber gas to oxygen
  • 9.7 After the sample chamber is switched to oxygen, heat to 750℃ at a heating rate of [the source source-text extraction is missing the heating rate value; requires confirmation against the source standard (source-text extraction)], and hold at constant temperature 750℃ for at least 5 min

7. Sampling and sample preparation

• 7.1, 7.2, 7.3: the source source-text extraction is severely missing; the content requires confirmation against the source standard (source-text extraction).
• 8.5: Place the sample on the oscillator and oscillate it; oscillation time 5 min, so that it is fully mixed and uniform. Note: If [the source source-text extraction is missing] is large or the ambient temperature is low, [the source source-text extraction is missing] may be used.
• 10.5: Remove the sample from the oscillator, take a sample with a scraper, weigh 20 mg±1 mg of the fully oscillated sample, and spread it evenly on the bottom of the crucible; the sampling time must not exceed 4 min (the source source-text extraction is “Amin”; requires confirmation against the source standard (source-text extraction)). After taking the sample, clamp the crucible containing the sample with tweezers, place it on the sample tray, and close the heating furnace.
• Referenced sampling standard: GB/T 4756 Petroleum liquids — Manual sampling.

8. Analysis procedure

• 8.1 Complete instrument calibration according to the operation manual.
• 8.2, 8.3, 8.4: the source source-text extraction is severely missing; the content requires confirmation against the source standard (source-text extraction). Among them, 8.4 shows wording such as “rinse clean with distilled water, dry for later use” (related to crucible cleaning; requires confirmation against the source standard (source-text extraction)).
• 8.5 Place the sample on the oscillator and oscillate for 5 min to mix thoroughly and uniformly.
• 8.6 Observe the balance and wait for the signal to stabilize.
• 8.7 Set the gas flow parameters (see clause 6).
• 10.1 Run the soot thermogravimetric analysis program in accordance with 9.1 to 9.7.
• 10.2 Before performing the operation in Chapter 9, the heating furnace temperature should be lower than 40℃ (the source source-text extraction is “404”; requires confirmation against the source standard (source-text extraction)).
• 10.3 Use tweezers to clamp the crucible and place it on the sample tray.
• 10.4 Press the “zero” key, wait for the instrument to complete “zeroing”, then remove the crucible and set it aside.
• 10.5 Sampling and weighing (see clause 7).
• 10.6 After stabilization, start the soot thermogravimetric analysis program, test, and record the thermogravimetric curve.
• 10.7 The heating furnace automatically cools down. Note: Clean compressed air may be used to purge and quickly bring the furnace temperature down to room temperature.

9. Qualitative and quantitative determination and calculation formula

• Quantitative basis (11.1): the soot content is the difference in mass fraction between the two plateaus of the sample before and after switching the gas atmosphere (before and after 650℃, that is, before and after 13 min).
• Figure 1 Soot thermogravimetric analysis diagram: below the X axis is marked time, and above is the sample temperature corresponding to the time. In the figure, the soot content of a certain sample is 3.6% (example).
• 11.1 also mentions “the difference in mass fraction from the 750℃ (test end point) plateau is [the source source-text extraction is missing]”; the relationship of this sentence to the foregoing definition requires confirmation against the source standard (source-text extraction).
• 11.2 For the statistical results of different samples in the [the source source-text extraction is missing] test, see Appendix A.
• Calculation formula: no independent formula is provided in the available source (expressed as a difference in mass fraction).

10. Precision

Appendix A (informative appendix) Statistical results of collaborative tests of different samples in different laboratories:

• A.1 The test results were calculated after four laboratories conducted round-robin tests on 10 samples, and each laboratory tested the same sample twice. Sample details: samples No. 1 to No. 8 are oil samples taken from the same CI-4 15W/40 oil after different operating times on a Mack-T8 bench; sample No. 9 is an oil sample taken from a CI-4 10W/40 oil after 200 h of operation on a ISM bench; sample No. 10 is an oil sample taken from a CH-4/SJ 10W/40 oil after 200 h of operation on a ISM bench.
• A.2 Calculated with reference to the relevant provisions of GB/T 6683:
  • Repeatability: the difference between two consecutive test results obtained by the same operator using the same instrument under the same test conditions on the same sample shall not be greater than 0.14% (mass fraction).
  • Reproducibility: the difference between two single and independent results obtained by different operators, in different laboratories, using different instruments, under the same test conditions on the same sample shall not be greater than 0.21% (mass fraction).
• Table A.2 Statistical results (within-laboratory standard deviation / between-laboratory standard deviation / within-laboratory tolerance / between-laboratory tolerance): the table data in the source source-text extraction are severely garbled; the values for each sample require confirmation against the source standard (source-text extraction); the identifiable tolerances are within-laboratory 0.14% and between-laboratory 0.21%.

11. Report

Report the mass fraction of soot content in the diesel engine oil sample (%), with the result accurate to 0.1%. (Chapter 12)

12. Referenced documents

• GB/T 4756 Petroleum liquids — Manual sampling (GB/T 4756—1998, EQV ISO 3170:1988)
• GB/T 6682—2008 Water for analytical laboratory use — Specification and test methods (GB/T 6682—2008, MOD ISO 3696:1987)
• GB/T 6683 Determination of precision data for petroleum product test methods (the source source-text extraction is “CB/T 6683”, requires confirmation against the source standard (source-text extraction))
• GB/T 1.1—2009 (mentioned in the foreword, drafting rules)
• ASTM D5967-10a (reference, non-normative reference)

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