The ASTM D445, IP 71 and ISO 3104 test methods specifies a procedure for the determination of the kinematic viscosity of liquid petroleum products, both transparent and opaque. Examples are kerosene, bitumen, waxes, fuel oils, diesel, gas oils, lubricants, residual oils, transformer oils, biodiesel, and used oils. The time is measured for a fixed volume of liquid to flow under gravity through the capillary of a calibrated viscometer under a reproducible driving head and at a closely controlled and known temperature inside a viscosity bath. The kinematic viscosity (determined value) is the product of the measured flow time and the calibration constant of the viscometer. Two such determinations are needed from which to calculate a kinematic viscosity result that is the average of two acceptable determined values.
Why is kinematic viscosity of liquid petroleum products important to know?
Many petroleum products, and some non-petroleum materials, are used as lubricants, and the correct operation of the equipment depends upon the appropriate viscosity of the liquid being used. In addition, the viscosity of many petroleum fuels is important for the estimation of optimum storage, handling, and operational conditions. Thus, the accurate determination of viscosity is essential to many product specifications.
Summary of ASTM D445, IP 71 and ISO 3104 test methods
The ASTM D445, IP 71 and ISO 3104 methods specify a procedure for the determination of the kinematic viscosity, ν, of liquid petroleum products, both transparent and opaque, by measuring the time for a volume of liquid to flow under gravity through a calibrated glass capillary viscometer inside a viscosity bath. The dynamic viscosity, η, can be obtained by multiplying the kinematic viscosity, ν, by the density, ρ, of the liquid. The result obtained from this test method is dependent upon the behaviour of the sample and is intended for application to liquids for which primarily the shear stress and shear rates are proportional (Newtonian flow behaviour). If, however, the viscosity varies significantly with the rate of shear, different results may be obtained from viscometers of different capillary diameters. The procedure and precision values for residual fuel oils, which under some conditions exhibit non-Newtonian behaviour, have been included. The range of kinematic viscosities covered by this ASTM D445, IP 71 and ISO 3104 test methods are from 0.2 mm²/s to 300 000 mm²/s) at all temperatures.
Why should you use a Tamson Viscosity bath to measure the kinematic viscosity of petroleum liquids?
The robust Tamson viscosity baths can be operated from ambient +5°C up to +230°C (41..446°F), the widest range in the industry. With the use of the built-in cooling coil and an external Tamson cooling circulator, span lies 5°C above the temperature of the cold flow of the external cooling circulator. The TV2000, TV4000(DC), and TV7000DC have a bath volume of 20, 40, and 70 litres respectively. The TV2000 has a cover with three openings and lids. The TV4000(DC) and TV7000DC have a cover with seven openings and lids. These openings accommodate glass capillary viscometers in viscometer holders. The TV7000DC is used to calibrate long thermometers, to calibrate master viscometers or for oxidation stability tests. A bath overflow outlet protects from expanding bath oil when the bath filling is expanding at higher temperatures. A bath drain is standard included. The bath is fitted with a double window of which the front pane is detachable for cleaning purposes.
Please contact our sales team (sales@tamson.nl) to get a quotation. Or visit our webshop to get price and technical information for a viscosity bath and accessories to determine the kinematic viscosity of liquid petroleum products conform to ASTM D445, IP 71 and ISO 3104.
