ASTM D4624 Measuring Apparent Viscosity by Capillary Viscometer
ASTM D4624 Standard Test Method for Measuring Apparent Viscosity by Capillary Viscometer at High-Temperature and High-Shear Rates
6. Apparatus
6.1 At the time this program was conducted, no suitable capillary viscometers were available commercially. Annex A1 tabulates the characteristics of the viscometers that were used in the ASTM evaluation of this test method. The precision of this test method was calculated from data obtained with viscometers that had length-to-diameter (L/D) ratios between 120 and 280. The viscometers described in Annex A1 were all research-type instruments.
6.2 For the convenience of anyone wishing to build an HTHS capillary viscometer, working drawings, specifications, and operating procedures are available for the viscometer used by Laboratory X. This design is offered because of its availability and not because of any implied preference.
6.3 The principal components of the two types of viscometers are as follows:
6.3.1 Constant Pressure Viscometer:
6.3.1.1 Capillary.
6.3.1.2 Means to control and measure oil temperature.
6.3.1.3 Means to set pressure drop.
6.3.1.4 Means to measure flow rate.
6.3.2 Constant Flow Rate Viscometer:
6.3.2.1 Capillary.
6.3.2.2 Means to control and measure oil temperature.
6.3.2.3 Means to set flow rate.
6.3.2.4 Means to measure pressure drop.
7. Sampling
7.1 A representative sample of test oil free from suspended solid material and water is necessary to obtain valid results. If the sample is suspected to contain suspended material, filter with 10 µm or finer filter paper.
