Viscosity instrumentation saybolt viscometer

The Saybolt viscometer works on a similar principle (ASTM D88)—the fluid is loaded to a tube calibrated to 60 ml. A cork is removed from the bottom of a narrow capillary and a timer is initiated. When 60 ml of the fluid is drained, the timer is halted. The time to drain the 60 ml volume is known as Saybolt seconds. The instrument operates at temperatures from ambient to as much as 99 °C. Because of the high sensitivity of viscosity to temperature, substantial efforts are devoted to maintaining isothermal conditions quoted uncertainties around the temperature are on the order of 0.03 °C. The accuracy of Saybolt viscometers is better than 0.2%. In order to ensure accuracy, they should be calibrated at regular intervals. For fully developed laminar flows, the drain time through the capillary at the base is directly proportional to viscosity. However, since the capillary section of the tube is short, a correction factor to the time is... 

Saybolt viscometer A type of instrument used to determine the viscosity of petroleum oils. It is based on the time in seconds for a given volume of oil to pass through an aperture at a controlled temperature and collect in a container with a volume of 60 millilitres. The Saybolt universal second is the unit used as a measure of the ldnemaUc viscosity. 

The Saybolt Universal and Saybolt Furol viscometers are widely used in the United States and the Engler in Europe. In the United States, viscosities on the lighter fuel grades are determined using the Saybolt Universal instrument at 38°C (100°E) for the heaviest fuels the Saybolt Enrol viscometer is used at 50°C (122°E). Similarly, in Europe, the Engler viscometer is used at temperatures of 20°C (68°E), 50°C (122°E), and in some instances at 100°C (212°E). Use of these empirical procedures for fuel oils is being superseded by kinematic system (ASTM D396 BS 2869) specifications for fuel oils. 

Orifice. Orifice viscometers, also called efflux or cup viscometers, are commonly used to measure and control flow properties in the manufacture, processing, and application of inks, paints, adhesives, and lubricating oils. Their design answered the need for simple, easy-to-operate viscometers in areas where precision and accuracy are not particularly important. In these situations knowledge of a true viscosity is unnecessary, and the efflux time of a fixed volume of liquid is a sufficient indication of the fluidity of the material. Examples of orifice viscometers include the Ford, Zahn, and Shell cups used for paints and inks and the Saybolt Universal and Furol instruments used for oils (Table 5). 

The unsuitable nature of many commercial instruments which are in common use clearly illustrates the confusion prevalent in the field of viscometric measurements. Many instruments measure some combination of properties which depend only partly on the fluid consistency since the flow is not laminar. In others the shear rates are indeterminate and the data cannot be interpreted completely. Examples of such units include rotational viscometers with inserted baffles, as in the modified Stormer instruments in which the fluid flows through an orifice, as in the Saybolt or Engler viscometers instruments in which a ball, disk, or cylinder falls through the fluid, as in the Gardiner mobilometer. Recently even the use of a vibrating reed has been claimed to be useful for measurement of non-Newtonian viscosities (M14, W10), although theoretical studies (R6, W10) show that true physical properties are obviously not obtainable in these instruments for such fluids. These various instru-... 

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