GB/T 11137-1989 Determination of kinematic viscosity of dark petroleum products (reverse-flow method) and calculation of dynamic viscosity

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Card type: Test method

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

• Standard number: GB 11137-89 (the file name is marked as GBT-11137-1989, the standard number in the original main text is written as GB 11137-89, and at another source-text extraction noise location it is written as GB 11187-89, requires confirmation against the source standard (source-text extraction))
• Chinese name: Determination of kinematic viscosity of dark petroleum products (reverse-flow method) and calculation of dynamic viscosity
• English name: Black petroleum products - Determination of kinematic viscosity (reverse-flow method) and calculation of dynamic viscosity (the original English name source-text extraction has noise, requires confirmation against the source standard (source-text extraction)))
• Replacement relationship: not provided in the available source

2. Scope of application and non-applicability

• Scope of application: applicable to dark petroleum products.
• Not applicable: not applicable to the determination of the viscosity of asphalt.
• Method content: specifies the method for determining the kinematic viscosity of dark petroleum products with a reverse-flow viscometer and for calculating the dynamic viscosity from the measured kinematic viscosity.

3. Method principle

The kinematic viscosity of dark petroleum products is determined by measuring the time for a certain volume of liquid to flow under gravity through a calibrated glass capillary viscometer (reverse-flow viscometer). From the product of the measured kinematic viscosity and its density, the dynamic viscosity of the liquid can be obtained. (Original text Chapter 4 Method summary)

4. Reagents and materials (purity / preparation)

• 5.2 Materials
  • a. Solvent naphtha: meets the NY-120 requirement in GB 1922 or other suitable solvent.
  • b. Chromic acid cleaning solution.
• 6 Reagents
  • a. Petroleum ether: 60~90°C, chemically pure.
  • b. 95% Ethanol: chemically pure.

5. Instruments and equipment

• 5.1.1 One set of Cannon-Fenske opaque viscometers. Meets the requirements for the BMN-3 type viscometer in ZBE 30014; dimensions and kinematic viscosity ranges are shown in the original figure and table.
• 5.1.2 Each viscometer must be calibrated for its constant in accordance with JJG 155.
• 5.1.3 Constant-temperature bath: same as the constant-temperature bath in GB 265, and with sufficient depth so that the constant-temperature bath liquid level is 20 mm above the sample liquid level in the viscometer, and the bottom of the viscometer is 20 mm above the bottom of the constant-temperature bath. The temperature is controlled at 0.1°C. The constant-temperature bath liquid may be distilled water, transparent mineral oil, or glycerol (glycerin), etc.
• 5.1.4 Mercury thermometer: meets the requirements of GB 514. The graduation value is 0.1°C.
• 5.1.5 Stopwatch: graduation value is 0.1 s.

Original viscometer dimensions and kinematic viscosity range table (dimension number | viscometer constant (mm²/s)/s | kinematic viscosity range mm²/s | capillary 2 inner diameter mm (±2%)):

• 25 | 0.002 | 0.4~2 | 0.31
• 50 | 0.004 | 0.8~4 | 0.42
• 75 | 0.008 | 1.6~8 | 0.54
• 100 | 0.015 | 3~15 | 0.63
• 150 | 0.035 | 7~35 | 0.78
• 200 | 0.1 | 20~100 | 1.02
• 300 | 0.25 | 50~200 | 1.26
• 350 | 0.5 | 100~500 | 1.48
• 400 | 1.2 | 240~1200 | 1.88
• 450 | 2.5 | 500~2500 | 2.20
• 500 | 8 | 1600~8000 | 3.10 (source-text extraction doubtful point, requires confirmation against the source standard (source-text extraction))
• 600 | 20 | 4000~20000 | 4.00
• Note: 1) The minimum flow time is all 200 s.

6. Recommended operating conditions

• Constant-temperature bath temperature control: 0.1°C.
• Constant-temperature time: when measuring viscosity at 50°C, the constant-temperature time of the viscometer in the constant-temperature bath shall not be less than 20 min; when measuring viscosity at 80°C or 100°C, the constant-temperature time of the viscometer shall not be less than 25 min.
• Sample flow time: should be greater than 200 s (8.1); the minimum flow time is all 200 s (table note).
• Density measurement temperature: the same temperature as that for viscosity measurement (8.6).

7. Sampling and sample preparation

• 7.1 For residual fuels and similar waxy products, whose viscosity can be affected by the preheating process, the following procedure shall be followed:
  • 7.1.1 Place the sample in the container in an oven and heat at 60±2°C for 1 h. Note: For highly viscous oils, the heating temperature may be appropriately increased so that the sample is completely mixed, but do not exceed the test temperature.
  • 7.1.2 Stir the sample thoroughly with a long glass rod until no sediment or waxy material adheres to the rod.
  • 7.1.3 Replace the container cover tightly and shake vigorously to mix completely, then pour the sample into a 100 mL beaker. Note: If the sample contains solid particles, it should be filtered through a 200 mesh (75 μm) filter screen.
• 7.2 Before measuring viscosity, the viscometer must be cleaned with solvent naphtha or petroleum ether. If the viscometer is contaminated with dirt, wash it successively with chromic acid cleaning solution, water, distilled water, or 95% ethanol, then dry it in an oven or blow it dry with hot air filtered through cotton.

8. Analytical procedure

• 8.1 Select a clean and dry viscometer so that the flow time of the sample is greater than 200 s.
• 8.2 Invert the viscometer, immerse tube 1 into the sample, and aspirate tube 3 so that the sample passes through tube 1 and fills the bulb to the filling mark a. Be careful not to introduce air bubbles. Remove the viscometer, wipe off the sample adhering to tube 1, return the viscometer to its normal position, and close tube 1 with a rubber stopper or a rubber tube with a screw clamp.
• 8.3 Install the viscometer in the constant-temperature bath so that the constant-temperature bath liquid level is above bulb D, and keep tube 1 vertical. When measuring viscosity at 50°C, the constant-temperature time of the viscometer in the constant-temperature bath shall not be less than 20 min; when measuring viscosity at 80°C or 100°C, the constant-temperature time of the viscometer shall not be less than 25 min. When any viscometer is being used to measure flow time, do not place or remove other viscometers in the constant-temperature bath.
• 8.4 After the viscometer has reached the required constant temperature, remove the rubber stopper or rubber tube from tube 1. Measure the time required for the sample to pass through viscometer bulb C (from mark b to c).
• 8.5 For samples treated according to clause 7.1, the viscosity measurement shall be completed within 1 h after heating.
• 8.6 At the same temperature as that for viscosity measurement, determine the density of the sample according to GB 1884 and GB 1885, to the nearest 0.001 g/cm³.

9. Qualitative and quantitative determination and calculation formulas

• 9.1 The kinematic viscosity of the sample ν (mm²/s) is calculated according to formula (1): ν = C · t Where: C — viscometer constant of bulb C, (mm²/s)/s; t — flow time of the sample, s.
• 9.2 The dynamic viscosity of the sample η (mPa·s) is calculated according to formula (2): η = ρ · ν Where: ρ — density of the sample at the same temperature as that for viscosity measurement, g/cm³; ν — kinematic viscosity of the sample, mm²/s.
• Reported value: take the arithmetic mean of two results from duplicate determinations as the kinematic viscosity of the sample. Take four significant figures.

10. Precision

Judge the reliability of the test results according to the following provisions (95% confidence level).

• 10.1 Repeatability: the difference between two results from duplicate determinations by the same operator shall not exceed the following values.
  • Temperature 50°C: repeatability 1.5% × X₁
  • Temperature 80°C and 100°C: repeatability 1.3% × (X₁ + 8)
  • Where X₁ is the arithmetic mean of the two results from duplicate determinations.
• 10.2 Reproducibility: the difference between two results submitted by different laboratories shall not exceed the following values.
  • Temperature 50°C: reproducibility 7.4% × X₂
  • Temperature 80°C and 100°C: reproducibility 4.0% × (X₂ + 8)
  • Where X₂ is the arithmetic mean of the two results submitted by different laboratories.

11. Report

Take the arithmetic mean of two results from duplicate determinations as the kinematic viscosity of the sample. Take four significant figures.

12. Referenced documents

• GB 265 Determination of kinematic viscosity of petroleum products and calculation of dynamic viscosity
• GB 514 Technical conditions for liquid thermometers for petroleum product testing
• GB 1884 Determination of density of petroleum and liquid petroleum products (hydrometer method)
• GB 1885 Petroleum measurement conversion tables
• GB 1922 Solvent naphtha
• ZB E 30014 Technical specifications for glass capillary viscometers
• JJG 155 Verification regulation for working capillary viscometers

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 for questions and answers