Viscosity Apparatus

Conforms to the specifications of: ASTM D445, 
Calibrated capillary viscometers are used to measure flow under gravity or vacuum at precisely controlled temperatures

• Delivery Time: 1 week

• Delivery Time: 1 week

A capillary viscometer is an instrument used to measure the viscosity, or thickness, of a liquid by measuring how long it takes the liquid to flow through a small-diameter tube, or capillary. The flow, or efflux, time is directly proportional to the liquid's kinematic viscosity, and may be converted directly to viscosity by use of a conversion factor unique to each instrument. Viscosity is generally temperature dependent, so the capillary viscometer is usually used in a controlled-temperature water bath set to a specific temperature.

Viscosity may be thought of as the internal friction of a liquid, or its tendency to resist flowing. Viscosity is thus an important property of fluids. It is of critical concern in lubricants, paints, beverages, and in any case where a liquid must be transferred, stirred, or manipulated.
A capillary viscometer may take any of several designs, but most common is the U-shaped or Ostwald viscometer, of which the Cannon-Fenske and Ubbelohde types are typical. A Cannon-Fenske capillary viscometer is a U-shaped piece of glass tubing bearing two glass bulbs or chambers on one arm, separated by a calibrated length of capillary tubing. Another bulb is low on the other arm, to which the sample is charged. The sample and the capillary viscometer are then suspended in a fixed-temperature water bath and allowed to come to thermal equilibrium.

• Delivery Time: 1 week