A model of the viscoplastic boundary layer of a yield stress fluid is described and, based on which, there is provided a method comprises the steps of: vibrating a vibratory transducer at resonance at a first resonant mode in a yield stress fluid and making a first measurement of the resonant frequency; providing a vibration to liquefy at least a portion of the yield stress fluid around the one or more vibratory transducers; while said portion of the yield stress material is liquefied, vibrating a vibratory transducer at resonance at the first resonant mode in the yield stress fluid and making a second measurement of the resonant frequency; and estimating the yield stress of the yield stress fluid based on the first and second measurements. The vibration to liquefy yield stress fluid around the one or more transducers may be provided by the making of the second measurement at an increased amplitude of vibration relative to the first measurement.

An inline fluid properties measurement device that includes a tube defining an interior space that includes at least one non-cylindrical volume, and having a fluid entrance and exit, and capable of conducting fluid from the fluid entrance to the fluid exit, through the at least one non-cylindrical volume. An excitation and sensing transducer assembly is positioned to torsionally drive the tube and to sense torsional movement of the tube and a controller is programmed to drive the excitation and sensing transducer to drive the tube in torsion, thereby translating the fluid in the at least one non-cylindrical volume, and to sense torsional movement of the tube, thereby producing a sense signal. Finally, a signal analysis assembly responsive to the sense signal to form a measurement of at least one property of the fluid.

A resonant sensor 1908 is used to determine fluid properties, the resonant sensor 1908 comprising a resonator 108 defining a lengthwise axis and having a central vibrational node (140), and a pair of opposed lengthwise end-portions (125); a support structure including a frame (115) and a set of flexible supports (110) extending from the frame to the central vibrational node and thereby supporting the resonator at the lengthwise midpoint; a driving and sensing assembly, adapted to drive the resonator to resonant motion and to sense resultant motion of the resonator and producing a motion sensed signal, responsive thereto; and a control and signal processing network adapted to control the driving and sensing assembly to drive the lengthwise end-portions in rotation about the lengthwise axis, in opposed rotational directions, and responsive to the motion sensed signal to determine at least one fluid property of a fluid under test in response to the motion sensed signal.

A blood coagulation test device includes: a container into which a test-object blood is placed; a stirring part for stirring the test-object blood in the container; an elastic body being connected to the stirring part and capable of deforming in response to a force received through stirring of the test-object blood from the stirring part; a control unit for transmitting a predetermined rotary motion to the stirring part and causing the stirring part to rotate in a reciprocating manner in a circumferential direction by rotating the elastic body in a reciprocating manner about an axis of the stirring part as a rotation axis and controlling the reciprocating rotation at a position separated by a predetermined diameter from the rotational axis; and a measurement unit for measuring a rotation angle pertaining to the reciprocating rotation of the stirring part.

A method and a device for the measurement of one or more fluid-mechanically effective parameters of a fluid, with a fluid pump which comprises a delivery element which is mounted in a magnet bearing, and the delivery element of the fluid pump is excited into an oscillation by way of an excitation device, wherein the oscillation parameters as well as, as the case may be, the oscillation behaviour is measured, and parameters of the fluid are determined from this.

Apparatuses and methods are disclosed for the analysing of non-Newtonian fluids and determining parameters to characterise the relationship between shear stresses and shear rates, i.e. the parameters of one or more rheological models of viscosity. A plurality of viscosity measurements are made in a fluid using one or more vibratory transducers operating at a plurality of frequencies. Parameters for the fluid are determined based on the measured viscosity values and the frequencies of vibration at which the viscosity measurements were obtained.

An apparatus for measuring blood coagulation data, and a use method and calibration method thereof are disclosed. The apparatus comprises: a movable support part (101), a fixed support part (102), a connection part (103), a rotary shaft (104), a magnet (105), a Hall element (106), and a processing unit (107). One end of the movable support part (101) is fixedly connected to the rotary shaft (104), and the other end of the movable support part (101) is connected to the fixed support part (102) by means of the connection part (103); the movable support part (101) is fixedly connected to the magnet (105); the rotary shaft (104) is able to rotate relative to the fixed support part (102) under the driving force of measured blood and drive the movable support part (101) to rotate; the movable support part (101) is able to move the magnet (105) to cause a change in the magnetic field of the magnet (105); the Hall element (106) is connected to the processing unit (107); the Hall element (106) is used for outputting a measurement electric signal according to the magnetic field change of the magnet (105); and the processing unit (107) is used for determining blood coagulation data of the measured blood according to the measurement electric signal. The present apparatus can improve the accuracy in measurement of blood coagulation data.

A rheometer apparatus and methods of use are provided. In one embodiment, the rheometer includes a sleeve having an interior space; a cylindrical bob disposed within the interior space of the sleeve and coupled to a first end of a bob shaft; a cross-spring pivot coupled to a second end of the bob shaft; an arm coupled to and projecting radially from the cylindrical bob; and a linear actuator coupled to the arm. In some embodiments, the rheometer apparatus may facilitate more accurate gel shear strength measurements and/or may be correlated with existing rheometer measurements.

An inline fluid properties measurement device that includes a tube defining an interior space that includes at least one non-cylindrical volume, and having a fluid entrance and exit, and capable of conducting fluid from the fluid entrance to the fluid exit, through the at least one non-cylindrical volume. An excitation and sensing transducer assembly is positioned to torsionally drive the tube and to sense torsional movement of the tube and a controller is programmed to drive the excitation and sensing transducer to drive the tube in torsion, thereby translating the fluid in the at least one non-cylindrical volume, and to sense torsional movement of the tube, thereby producing a sense signal. Finally, a signal analysis assembly responsive to the sense signal to form a measurement of at least one property of the fluid.

A method and a device for the measurement of one or more fluid-mechanically effective parameters of a fluid, with a fluid pump which comprises a delivery element which is mounted in a magnet bearing, and the delivery element of the fluid pump is excited into an oscillation by way of an excitation device, wherein the oscillation parameters as well as, as the case may be, the oscillation behaviour is measured, and parameters of the fluid are determined from this.