Abstract: A vibration viscosimeter having a resilient wire loop to be vibrated and an electrical drive therefor. The energizing signal for the drive is alternately kept 30 degrees lagging and 30 degrees leading the vibration or vice versa. Viscosity may then be computed as a function of the signal periods and six constants.

Abstract: A turbine flowmeter having a rotor with a hub and conventional blades outside the hub. An impeller is fixed inside the hub to keep an axial pressure on the rotor to maintain it axially slidable but spaced from a diffuser at each end of the hub. Alternative constructions include upstream diffuser passageways and a hub somewhat larger than the upstream diffuser.

Abstract: A viscosimeter utilizing two different turbine flowmeters driven in series in a closed loop by a pump. It has been discovered that the viscosity v of the pumped fluid may be calculated from the expressionv=Af.sub.j -Bf.sub.i +CwhereA, B and C are constants which may be determined by turbine flowmeter, viscosimeter or other analytical or empirical calibration, andf.sub.i and f.sub.j are the pulse repetition frequencies at the outputs of the respective turbine flowmeters.

Abstract: A vibration densitometer having a temperature compensated probe.

Abstract: A vibration densitometer which can be calibrated to an accuracy never before possible, i.e. to within an error of 0.25 percent or less, and in two fluids or gases or gas mixtures, one, both or none being an elemental fluid or gas. The fluids or gases or fluid or gas mixtures have different density equationsd.sub.i = A.sub.i T.sub.i.sup.2 - i B.sub.id.sub.j = A.sub.j T.sub.j.sup.2 - B.sub.jThe first of which is converted by .DELTA.T.sub.i, an extremely linear function of container or pipeline pressure, such thatd.sub.j = A.sub.i (T.sub.i - .DELTA.T.sub.i).sup.2 - B.sub.i.Whered.sub.i and d.sub.j are the two respective fluid densities, T.sub.i andT.sub.j are two periods directly proportional to the reciprocals of the respective vibration frequencies, and A.sub.i, A.sub.j, B.sub.i and B.sub.j are constants.It was heretofore unknown to calibrate a vibration densitometer in two fluids or gases or fluid or gas mixtures with the aforesaid extremely small error.