Patent ID: 7614285

Claim:
A method of fluid characterization that includes: A) driving current through a first coil in such a manner as thereby to drive a ferromagnetic bob magnetically through a bob path occupied by a sample fluid and induce in a second coil by mutual inductance a resultant detection-coil signal that depends on the bob's position along the bob path; B) taking measurements of the detection-coil signal's values at a plurality of times during a single traversal of the bob path; C) determining respective bob positions from a plurality of the values of the detection-coil signal thus measured during that single traversal; D) determining a rheological characteristic of the sample fluid from a plurality of the bob positions thus determined by: i) computing a plurality of velocity values from the determined bob positions; ii) classifying sequences of the measurements taken in a single traversal into acceleration and terminal-velocity regimes in accordance with comparisons of successive said velocity values; and iii) basing determination of the rheological characteristic from the measurements taken in the terminal-velocity regime without employing the measurements taken in the acceleration regime; and E) generating a characterizer output signal indicative of the rheological characteristic thus determined.