SN/T 3587-2016Textiles for import and export - Determination of residual admides solvent - Gas chromatography-mass spectrometry method (English PDF)

1 Scope

This Standard specifies the method of viscosity determination of crude petroleum through coaxial cylinder rotational viscometer.

This Standard is applicable to the determination of viscosity or apparent viscosity of crude petroleum whose water content does not exceed 0.5% (mass fraction).

2 Principle of Measurement

Rotational cylinder places the surrounding fluid in stable layer-by-layer rotational flow;

the viscous torque of the fluid will act on the cylinder. The relations between the fluid’s viscosity and torque can be expressed in accordance with Formula (1).

Where,

eta---the viscosity of fluid, expressed in (Pa-s);

M---the fluid’s viscous torque acting on the cylinder, expressed in (N-m);

omega---the cylinder’s rotational speed, expressed in (rad/s);

K---flow field constant, expressed in (m-3).

In accordance with the relations between M and tau, omega and gamma, shear stress gamma on the cylindrical flow layer shall be expressed in Formula (2); viscosity or apparent viscosity shall be calculated in accordance with Formula (3) (in terms of non-Newtonian fluid, eta shall be apparent viscosity etaa).

Where,

4.2.2 Use the electronic balance to weigh sample mass (density is already known), which shall be slightly higher than the corresponding mass of the stipulated volume;

place it into an outer measuring cylinder, which is previously heated.

4.2.3 In terms of sample, which maintains flow state at room temperature, directly inject the sample for determination in accordance with the determination volume.

5 Result Calculation

5.1 In terms of rotational viscometer, whose viscosity value cannot be directly read, take the last alpha value. In accordance with Formula (2) and Formula (3), calculate the viscosity value or apparent viscosity value.

6 Precision

In accordance with the following stipulations, determine the precision of the determination result (95% confidence level).