The fundamental designs and some other aspects of Soviet and Western rolling-ball flowmeters are discussed. The concept of hydrodynamic correction of tangential characteristics is presented for tangential-type flowmeters, and some experimentally determined characteristics of flow configurations are compared. The design of the NK-1 rolling-ball flowmeter model is described. The NK-1 rolling-ball flowmeter which measures the volumetric rate of flow with viscosity compensation was developed at the Warsaw Polytechnical Institute, and the NK-1 and NK-2 prototype designs were put to operational testing in 1966. They were employed for measuring fuel consumption in high-compression engines in building machinery and for in-flight measurement of aircraft-engine fuel consumption.
Edited trans. of Pomiary, Automatyka, Kontrola (Poland) v14 n2 p56-58 1968, by L. Marokus.