GB/T 30515-2014 Determination of kinematic viscosity of transparent and opaque liquid petroleum products and calculation of dynamic viscosity

Summary page. This page is a compiled excerpt/summary of the standard — it is not the full standard text and does not replace it. Verify every value against the official standard and the product certificate before use.

Applies to transparent and opaque liquid petroleum products.

Evidence note: this page is compiled from the original text of this edition; technical review is pending. This round checked the gravity correction equation, the symbols of the precision means and the additive index; the viscometer ranges, the complete thermometer specifications and the controlled operating steps of the annexes have not been fully reviewed, and the page cannot serve as an operating procedure or a batch certificate. Method precision is not the uncertainty of a commercial batch; the specific version and applicability conditions must still be checked before use. Verification note: [to be verified] and [source unclear] mark places where the original text of the standard still has to be checked and do not mean that verification has been completed. Do not use these values or steps directly as a basis for work.

Scope: Applies to transparent and opaque liquid petroleum products. It specifies a method for determining the kinematic viscosity of liquid petroleum products using glass capillary kinematic viscometers, and a method for calculating their dynamic viscosity. NOTE (original): the viscosity result obtained depends on the characteristics of the sample and applies mainly to liquids in which shear stress is proportional to shear rate (that is, Newtonian liquids); if the viscosity of a liquid is markedly affected by shear rate, results obtained with capillary viscometers of different internal diameters may differ. This standard also includes the test procedure and precision provisions for the viscosity determination of fuel oils that behave as non-Newtonian liquids under certain conditions. Not applicable: the material available does not provide an explicit list.

Principle: At a known, strictly controlled temperature and under a reproducible driving head, the time is measured for a fixed volume of liquid to flow under gravity through a calibrated glass capillary viscometer; the product of the measured time and the viscometer calibration constant is the kinematic viscosity of the liquid. The dynamic viscosity is obtained as the product of the kinematic viscosity and the density of the liquid. (Clause 4, summary of method)

Apparatus: Viscometers 6.1.1 The types of glass capillary viscometer are given in Annex A and shall comply with GB/T 30514 or SH/T 0173-1992; viscometers shall be calibrated and verified, and the precision of the kinematic viscosity measurement shall comply with clause 14. Automatic viscometers may also be used if their precision is within the range of clause 14. When the kinematic viscosity is less than 10 mm²/s and the flow time is less than 200 s, a kinetic energy correction is required (see GB/T 30514). 6.1.2 Viscometers shall be calibrated or verified as specified in GB/T 30514 or JJG 155, and the viscometer constant determined. 6.2 Viscometer holder: with the upper meniscus directly above the lower meniscus, the deviation from vertical is less than 1°; where the upper meniscus is offset from the position of the lower meniscus, the deviation from vertical is less than 0.3° (see GB/T 30514). 6.3 Constant-temperature bath 6.3.1 A transparent liquid is used as the medium, of sufficient depth that the bath liquid level is at least 20 mm above the sample level in the viscometer and the bottom of the viscometer is at least 20 mm above the bottom of the bath. 6.3.2 Temperature control: in the range 15 °C to 100 °C the difference between the bath medium temperature and the set temperature shall not exceed ±0.02 °C; outside the range 15 °C to 100 °C it shall not exceed ±0.05 °C. 6.4 Temperature measuring device 6.4.1 In the range 0 °C to 100 °C, a calibrated glass liquid-in-glass thermometer with an accuracy of ±0.02 °C or better may be used (see Annex B), or another device of equivalent accuracy. Where two thermometers are used in the same bath, their readings shall not differ by more than 0.04 °C. 6.4.2 Outside the range 0 °C to 100 °C, a calibrated glass liquid-in-glass thermometer with an accuracy of ±0.05 °C or better may be used; two thermometers measuring the same bath shall not differ by more than 0.1 °C. 6.5 Timer 6.5.1 Accurate to 0.1 s or better, for measuring times in the range 200 s to 900 s, with a reading accuracy within ±0.07%. 6.5.2 Check the accuracy of the timer periodically and record the results of the check.

Reagents and reference materials: Cleaning liquid: chromic acid cleaning solution or a chromium-free strongly oxidizing acid cleaning solution. (Hazard warning for chromic acid; details in the original.) 5.2 Sample solvent: completely miscible with the sample, filtered before use. NOTE: light gasoline and naphtha are suitable solvents for most samples; for residual fuel oils it may be necessary to use an aromatic solvent such as toluene or xylene to dissolve the sample and remove asphaltenes. 5.3 Drying solvent: volatile and miscible with the sample solvent and with water, filtered before use. NOTE: acetone is a suitable drying solvent. 5.4 Water: deionized or distilled water meeting the grade 3 water requirements of GB/T 6682. 5.5 Certified viscosity reference oils: used to check the conformity of the test process. Viscosity reference oils specified in GB/T 30514 may be used, as may those specified in SH/T 0526.

Key conditions: Bath temperature control: ±0.02 °C within 15 °C to 100 °C; ±0.05 °C outside that range (6.3.2). Temperature measurement: a thermometer of ±0.02 °C or better accuracy for 0 °C to 100 °C; a thermometer of ±0.05 °C or better accuracy outside that range (6.4). Flow time: not less than 200 s, or the longer time specified in GB/T 30514 (8.2). Timing accuracy: to 0.1 s (9.2, 10.3). Temperature equilibration time: 30 min is generally sufficient, except for samples of very high kinematic viscosity (NOTE to 9.1.2). Pre-treatment of opaque liquids: heating in an oven at 60 °C ± 2 °C for 1 h (10.1.1); immersion in a boiling water bath for 30 min (10.1.5); adjusting the sample volume 10 min after placing in the constant-temperature bath (10.2.1).

Calculation and results: The kinematic viscosity ν (mm²/s) is calculated by equation (2): ν = C × t where: ν is the kinematic viscosity, mm²/s; C is the viscometer constant, mm²/s²; t is the flow time, s. 12.2 The dynamic viscosity η (mPa·s) is calculated by equation (3): η = ν × ρ × 10⁻³ where: η is the dynamic viscosity of the sample, mPa·s; ν is the kinematic viscosity of the sample, mm²/s; ρ is the density of the sample at the same temperature as the kinematic viscosity determination, kg/m³. 13 Expression of results: report the test result for kinematic viscosity and/or dynamic viscosity to four significant figures, together with the test temperature. Correction of the calibration constant (7.2): where the acceleration due to gravity in the testing laboratory differs from that in the calibrating laboratory by more than 0.1%, C₁ = (g₁/g₂) × C₂. C₁ and g₁ refer to the testing laboratory, C₂ and g₂ to the calibrating laboratory; the constant is in mm²/s² and the acceleration due to gravity in m/s².

Quality control: The reliability of the test results is judged at the 95% confidence level. 14.1 Determinacy (d): the difference between determination values obtained by consecutive determinations of one test result in the same laboratory, by the same operator, with the same apparatus, shall not exceed the requirements of Table 1. Table 1 Determinacy (y is the mean of the two determination values compared) | Sample | Temperature / °C | Determinacy | | --- | --- | --- | | Base oils | 40 and 100 | 0.002 0y or 0.20%y (see note 1) | | Blended lubricating oils | 40 and 100 | 0.001 3y or 0.13%y (see note 2) | | Blended lubricating oils | 150 | 0.015y or 1.5%y (see note 3) | | Petroleum waxes | 100 | 0.008 0y or 0.80%y (see note 4) | | Residual fuel oils | 80 and 100 | 0.011(y+8) (see note 5) | | Residual fuel oils | 50 | 0.017y or 1.7%y (see note 5) | | Lubricating oil additives | 100 | 0.001 06y^1.1 (see note 6) | | Gas oils | 40 | 0.001 3(y+1) (see note 7) | | Kerosene | −20 | 0.001 8y (see note 8) | 14.2 Repeatability (r): the difference between two test results obtained by consecutive determinations of the same sample in the same laboratory, by the same operator, with the same apparatus, under the same conditions, shall not exceed the requirements of Table 2. Table 2 Repeatability (x is the arithmetic mean of the two repeat kinematic viscosity test results compared, mm²/s) | Sample | Temperature / °C | Repeatability / mm²/s | | --- | --- | --- | | Base oils | 40 and 100 | 0.001 1x or 0.11%x (see note 1) | | Blended lubricating oils | 40 and 100 | 0.002 6x or 0.26%x (see note 2) | | Blended lubricating oils | 150 | 0.005 6x or 0.56%x (see note 3) | | Petroleum waxes | 100 | 0.014 1x^1.2 (see note 4) | | Residual fuel oils | 80 and 100 | 0.013(x+8) (see note 5) | | Residual fuel oils | 50 | 0.015x or 1.5%x (see note 5) | | Lubricating oil additives | 100 | 0.001 92x^1.1 (see note 6) | | Gas oils | 40 | 0.004 3(x+1) (see note 7) | | Kerosene | −20 | 0.007x (see note 8) | 14.3 Reproducibility (R): the difference between two single, independent test results obtained by different laboratories, different operators and different apparatus on the same sample shall not exceed the requirements of Table 3. Table 3 Reproducibility (x is the arithmetic mean of the two single independent kinematic viscosity test results compared, mm²/s) | Sample | Temperature / °C | Reproducibility / mm²/s | | --- | --- | --- | | Base oils | 40 and 100 | 0.006 5x or 0.65%x (see note 1) | | Blended lubricating oils | 40 and 100 | 0.007 6x or 0.76%x (see note 2) | | Blended lubricating oils | 150 | 0.018x or 1.8%x (see note 3) | | Petroleum waxes | 100 | 0.036 6x^1.2 (see note 4) | | Residual fuel oils | 80 and 100 | 0.04(x+8) (see note 5) | | Residual fuel oils | 50 | 0.074x or 7.4%x (see note 5) | | Lubricating oil additives | 100 | 0.008 62x^1.1 (see note 6) | | Gas oils | 40 | 0.008 2(x+1) (see note 7) | | Kerosene | −20 | 0.019x (see note 8) | NOTE: the precision of used oils cannot be established, but it is expected to be poorer than that of blended lubricating oils; because such used oils vary extremely widely, their precision is very difficult to establish. Notes on the source of the precision data (notes 1 to 8 of clause 14): base oils (first published 1989), blended lubricating oils at 40 °C and 100 °C (first published 1991), blended lubricating oils at 150 °C (first published 1991), petroleum waxes (first published 1988), residual fuel oils (first published 1984), additives (first published 1997), gas oils (first published 1997), kerosene (first published 1997).

Normative references: GB/T 514-2005 Specification for glass liquid-in-glass thermometers for petroleum product testing GB/T 1884 Crude petroleum and liquid petroleum products — Laboratory determination of density (Hydrometer method) (GB/T 1884-2000, eqv ISO 3675:1998) GB/T 1885 Petroleum measurement tables GB/T 6682 Water for analytical laboratory use — Specification and test methods (GB/T 6682-2008, ISO 3696:1987, MOD) GB/T 30514-2014 Glass capillary kinematic viscometers — Specifications and operating instructions (ISO 3105:1994, MOD) JJG 155 Verification regulation of working capillary viscometers SH/T 0173-1992 Specification for glass capillary viscometers SH/T 0526 Viscosity reference oils SH/T 0604 Crude petroleum and petroleum products — Determination of density (Oscillating U-tube method) (SH/T 0604-2000, eqv ISO 12185:1996)

View public related products