Falling-needle viscometer

In the Irvine-Park falling needle viscometer (FNV) (194), the moving body is a needle. A small-diameter glass or stainless steel needle falls vertically in a fluid. The viscous properties and density of the fluid are derived from the velocity of the needle. The technique is simple and useflil for measuring low (down to lO " ) shear viscosities. The FNV-100 is a manual instmment designed for the measurement of transparent Newtonian and non-Newtonian... 

Falling needle viscometer, 27 738 Falling rate drying, 9 109-110, 113-115 Falling rate period, 9 97 Falling rod viscometer, 27 738 False Irish moss, common and scientific names, 3 188t... 

Shear Viscosity. There are three main types of viscometers the rotational type, the flow-through-constriction type, and the flow-around-obstruction type. The concentric cylinder and the cone-and-plate are the two primary classes of rotational viscometers. The capillary tube is an example of the flow-through-constriction viscometers. Falling-ball or falling-needle viscometers are examples of the flow-around-obstruction type. 

In the case of the falling-ball viscometer, details may be found in Ref. 8. Reference 9 provides detailed coverage of the falling-needle viscometer. 

N. A. Park, Measurement of Rheological Properties of Non-Newtonian Fluids With the Falling Needle Viscometer, Ph.D. thesis, Mech. Eng. Dept., State Univ. of New York at Stony Brook, 1984. 

Park, N. A. and T. F. Irvine, Jr., Measurements of rheological fluid properties with the falling needle viscometer. Rev. Sci. Instrum. 59 2051-2057 (1988). 

Like the falling needle, the falling ball viscometer can be sealed to [nevent evaporation and permit measurements to be taken at high pressure. 

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