Abstract: A method and apparatus for estimating electromagnetic forces active in an electric machine. The method includes the steps of: measuring at least one first operation parameter of the electric machine while the electric machine is operated under at least one operational condition, and estimating electromagnetic forces active in an electric machine during operation of the electric machine by multiplying the measured at least one first operation parameter and a respective second operation parameter provided by a stored structural/vibro-acoustic model.

Abstract: The subject of the invention is a method and a device for determination of a torsional deflection of a rotation shaft in the electromechanical drivetrain.

Abstract: A device is disclosed for measuring torsional vibrations superimposed on rotating equipment such as a shaft. The device may be fastened to a rotating shaft by a collar and includes a sensor array comprising two or more accelerometers measuring the radial acceleration of the sensor array and the tangential acceleration of the sensor array. The gravitational component of the accelerometer signals is identified either by isolation in one of the signals, or by comparing two or more signals. From the tangential and radial acceleration signals, a torsional vibration amplitude is calculated from the ratio of the tangential acceleration and the radial acceleration. The radial acceleration is further used to determine the average velocity of the sensor array. The tangential acceleration may further be integrated to obtain the angular velocity of the sensor array, or further integrated to obtain the angle rotated through.

Abstract: A transmission includes an input shaft and an output shaft, the input shaft selectively accepting a torque input from a prime mover, and the output shaft selectively providing torque output to a driveline. A controller determines a shaft displacement angle representing an angle value of rotational displacement difference between at least two shafts of the transmission, and performs a transmission operation responsive to the shaft displacement angle.

Abstract: A pulsating inhaler comprising: (a) a fluid oscillator providing focused fluid columns with a series of alternating high and low pressure zones and (b) at least one outlet orifice adapted for delivering said focused fluid column to the respiratory tract of said patient. The fluid oscillator further comprises a piston which is actuated by a motor with an eccentric mechanism. According to alternative embodiment of the invention, the fluid oscillator comprises a rotating disc having a missing section.

Abstract: Embodiments of the invention relate to a thrust stand and a method of measuring thrust. Embodiments of the invention pertain to a method of calibrating a thrust stand. Embodiments of the subject thrust stand can incorporate a passive eddy current based damper. Specific embodiments of the passive eddy current based damper can function without contact with the balance arm. Further specific embodiments of the passive eddy current based damper can be used in a vacuum. Embodiments can utilize signal analysis techniques to identify and reduce noise. A logarithmic decrement method can be used to calibrate the thrust stand. Force measurements can be made with embodiments of the subject thrust stand for a standard macroscale dielectric barrier discharge (DBD) plasma actuator and/or other thrust producing devices.

Abstract: A current operational state of a program-controlled domestic appliance is monitored while it carries out an operating process. The monitoring system includes a retrofit module and a communication device separate from the retrofit module and from the domestic appliance. The retrofit module has a fastening arrangement for releasable fastening on an outer face of an appliance housing, a data exchange unit for wireless communication, and a sensor arrangement with a magnetic field sensor that detects a magnetic field that is generated by a drive motor of the domestic appliance and that penetrates outwards through the appliance housing. The system determines the current operational state of the domestic appliance with the aid of detected measured values of the magnetic field and outputs the state via the communication device.

Abstract: The invention relates to a method of monitoring a wear of a gearbox in a power station, such as a windmill, water-wheel or tidal power station, the gearbox comprising at least two shafts, cogwheels and bearings as components of the gearbox. The method comprises sensing an angular position at the shafts by a rotational shaft encoder and monitoring the wear of the transmission-unit according to differences of the sensed angular positions and generating a condition signal representative of the wear of the gearbox according to the monitored differences. The monitoring comprises an additional sensing of at least one additional degree of freedom, in particular an axial and/or eccentric displacement, of at least one of the shafts caused by wear of at least one of the components of the gearbox, and generating the condition signal according to the displacement and differences in the at least two degrees of freedom.

Abstract: A torque-measuring device with an acceleration transducer yields more informative measured results. The acceleration transmitter may be inseparably fastened to a carrier which in turn is inseparably joined to a torsion member. The torsion member and the carrier may be formed in one piece with one another. The torsion member may be a shaft and the carrier may be a flange.

Abstract: An RFID tag reading system affixed to a machine bearing housing is provided. The reading system includes a mobile data collector having an RFID reader for reading a unique identity of the RFID tag, an magnet electro-mechanically connected to the mobile data collector and a magnet mounting pad fixed to the machine housing. The magnet mounting pad having a ferromagnetic contact body for housing the magnet mounting pad and an RFID antenna disposed within the RFID tag for transmitting a unique identity of the RFID tag. The RFID tag is disposed within the ferromagnetic contact body. The magnet is magnetically connected to the magnet mounting pad. The mobile data collector automatically reads the unique RFID tag identity transmitted from the antenna of the RFID tag when the combination mobile data collector and magnet are placed onto the RFID mounting pad.

Abstract: An electric power steering apparatus having a function for detecting a steering speed, includes a time stamp attaching section that attaches a time stamp (ATi) to a detection signal (Ai) and attaches a time stamp (BTj) to a detection signal (Bj); a storing section that stores the detection signal (Bj) to which the time stamp (BTj) is attached; a synchronous signal searching section that searches the detection signal (Bj) most synchronized with the detection signal (Ai) based on the time stamps (ATi and BTj); a vernier calculating section that performs a calculation of an angle difference between synchronous signals searched by the synchronous signal searching section and a vernier calculation and outputs an absolute steering angle of a sensor reference; an initial steering angle calculating section that calculates an initial steering angle value from the absolute steering angle; and a steering angle output section that obtains a steering angle.

Abstract: The invention relates to a method for damping vibrations while checking a drivetrain which has at least one shaft and to a device for carrying out the method. The shaft is connected to at least one drive or load machine for adjustment of a drive or load torque, a target value of the drive or load torque being specified for the machine. A shaft torque which is dependent on the relative rotation between two points on the shaft is measured, and the measured shaft torque as such is applied to the target value of the drive or load torque.

Abstract: Exemplary embodiments provide a surface of a rotating element with both a phase reference mark and a plurality of additional marks. A proximity probe detects the passage of both the phase reference mark and the plurality of additional marks as they rotate through a detection zone. Both a phase reference signal and a vibration reference signal are generated, which signals are used to calculate lateral and angular (and optionally torsional) vibration of the rotating elements.

Abstract: A sound sensor, a hydrophone including the sound sensor, and a pressure balancing device for using for the hydrophone are provided. The hydrophone includes: a sensor including a sensing part and a pressure balancing part; a printed circuit board (PCB) that is electrically connected to the sensor; a case that houses the sensor and the PCB and that has an opening at one side thereof; an elastic membrane that covers the opening of the case; and a signal line that is electrically connected to the PCB to be extended to the outside of the case. The pressure balancing part includes a diaphragm of a thin film and a support that supports the diaphragm. A pressure balancing hole is formed at one side of the pressure balancing part, and at the inside of the pressure balancing part, a channel that is connected to the pressure balancing hole is formed, and a compressible gas is filled in the channel.

Abstract: A strain sensor apparatus for a rotatable shaft including a radiation emitter/receiver, a vibration element attached to the shaft and a reflector that is positioned to reflect radiation onto the vibration element.

Abstract: A strain sensor apparatus for a rotatable shaft including an emitter/receiver, a vibration element attached to the shaft and arranged for receiving and reflecting signals to and from the emitter/receiver wherein the vibration element includes asymmetric stiffness properties between a radial and axial and/or circumferential directions relative to a rotational axis of the shaft.

Abstract: A strain sensor apparatus for a rotatable shaft including a radiation emitter/receiver, a vibration element attached to the shaft and a radiation-reflective annulus surrounding the shaft and vibration element.

Abstract: Some embodiments provide a system that analyzes telemetry data from a computer system. During operation, the system obtains the telemetry data as a set of telemetric signals from the computer system and validates the telemetric signals using a nonlinear, nonparametric regression technique. Next, the system assesses the integrity of a power supply unit (PSU) in the computer system by comparing the telemetric signals to one or more reference telemetric signals associated with the computer system. If the assessed integrity falls below a threshold, the system performs a remedial action for the computer system.

Abstract: The present disclosure relates to a method for controlling at least one proximity sensor of a wind turbine, the wind turbine comprising a rotor shaft, the at least one proximity sensor being adapted to measure a radial displacement of the rotor shaft; the method includes: providing at least one reference value, detecting an output of the at least one proximity sensor, the output depending on a measured distance by the respective proximity sensor; comparing the detected output of the proximity sensor with at least one reference value.

Abstract: A method of detecting and monitoring torsional oscillation in a mechanical coupling between a prime mover and a multiphase alternating current (AC) electrical generator, comprises the steps of: detecting in at least one received signal variations that are indicative of changes in the rotational speed of the electrical generator; extracting information from the detected variations that are indicative of torsional oscillation to produce a torsional oscillation signal that has information relating to at least the amplitude of the torsional oscillation; and monitoring the torsional oscillation signal to determine the presence and severity of the torsional oscillation in the mechanical coupling.

Abstract: A fiberoptic multi-parameter sensing system for monitoring turbomachinery system shaft static and dynamic torques, vibration modes and associated operation status includes a multi-furcated fiber bundle based optical splitter configured to transmit light to a surface of at least one turbomachinery system shaft through a plurality of optical fiber bundles disposed at a plurality of locations in proximity to the surface of the at least one shaft, in which the plurality of locations together are arranged in a substantially axial direction between the ends of the at least one shaft.

Abstract: A solution is provided for tuning the frequency of a torsional mode of interest of a rotating body (such as a generator rotor torsional mode) by adding a detuner to act as an undamped torsional vibration absorber. The detuner may be coupled to an overhung shaft extending from the rotating body. The detuner may be modular, therefore weight can be added or subtracted easily from the detuner in order to adjust the stiffness and/or inertia of the overhung shaft. This change in stiffness and/or inertia yields a torsional frequency of oscillation in the overhung shaft substantially similar to the natural frequency of the torsional mode of interest of the rotating body, therefore forcing the frequency of the torsional mode of interest of the rotating body above or below its torsional natural frequency.

Abstract: Torsional oscillation of a shaft in a swing drive system of an excavator is minimized by monitoring torsional strain of the shaft. An electric motor provides torque to the shaft in response to a drive signal provided by a converter. A compensation circuit produces a compensation signal as a function of torsional strain of the shaft. A field excitation circuit or regulator powers a converter as a function of the compensation signal such that a counter torque is provided to the shaft and torsional oscillation of the shaft is reduced.

Abstract: Embodiments of a mechanical device to facilitate in-situ measurements of vibration associated with a corresponding component in a computer system are described. This mechanical device includes a housing that has approximately a same mass as the component, approximately a same distribution of mass about a geometric center of the component, and approximately a same form factor as the component. Moreover, the mechanical device includes one or more vibration sensors, which are mechanically coupled to the housing, and which are configured to perform the in-situ vibration measurements.

Abstract: Exemplary embodiments provide a surface of a rotating element with both a phase reference mark and a plurality of additional marks. A proximity probe detects the passage of both the phase reference mark and the plurality of additional marks as they rotate through a detection zone. Both a phase reference signal and a vibration reference signal are generated, which signals are used to calculate lateral and angular (and optionally torsional) vibration of the rotating elements.

Abstract: A solution is provided for tuning the frequency of a torsional mode of interest of a rotating body (such as a generator rotor torsional mode) by adding a detuner to act as an undamped torsional vibration absorber. The detuner may be coupled to an overhung shaft extending from the rotating body. The detuner may be modular, therefore weight can be added or subtracted easily from the detuner in order to adjust the stiffness and/or inertia of the overhung shaft. This change in stiffness and/or inertia yields a torsional frequency of oscillation in the overhung shaft substantially similar to the natural frequency of the torsional mode of interest of the rotating body, therefore forcing the frequency of the torsional mode of interest of the rotating body above or below its torsional natural frequency.

Abstract: A contactless SAW based torque and temperature sensor comprising a first (2) and second (3) SAW resonator provided on a substrate made of Y+34° cut of quartz. The first SAW resonator (2) has its principle axis inclined at +45° to the X-axis of the substrate, which, in use is either aligned with the longitudinal axis of the device who torque is to be measured or is perpendicular thereto, and the second SAW (3) has its principle axis inclined at ?45° to the X-axis of the substrate. A third SAW (4) has its principle axis inclined at an angle of 30 degrees to the X-axis of the substrate. Each said SAW resonator (2,3,4) is formed by laying a film of aluminum on the substrate having a thickness (h) and the SAW resonators have an average operating wavelength ? where the ratio h/? is in the range 0.021 to 0.032.

Abstract: A method of detecting and monitoring torsional oscillation in a mechanical coupling between a prime mover and a multiphase alternating current (AC) electrical generator, comprises the steps of: detecting in at least one received signal variations that are indicative of changes in the rotational speed of the electrical generator; extracting information from the detected variations that are indicative of torsional oscillation to produce a torsional oscillation signal that has information relating to at least the amplitude of the torsional oscillation; and monitoring the torsional oscillation signal to determine the presence and severity of the torsional oscillation in the mechanical coupling.

Abstract: A contactless SAW based torque and temperature sensor includes three SAW resonators 2, 3, 4 mounted on a common substrate 1 made of Y+34° cut of quartz. The first SAW 2 has its principle axis inclined at +45° to the X-axis of the substrate, which, in use, is either aligned with the longitudinal axis of a device whose torque is to be measured or is perpendicular thereto, and the second SAW 3 has its principle axis inclined at ?45° to the X-axis of the substrate. The third SAW 4 is positioned with its principle axis inclined at an angle, preferably in the range of 0 to 30 degrees, to the principle axis of both the first 2 and second 3 resonators so that none of the SAWs are parallel, the third SAW 4 enabling temperature measurements to be taken.

Abstract: A contactless precision, optical distance and angle measurement method and system optically measuring the position of a moveable object, the bending of the object, the torque applied to the object and the object's rotational velocity. The present invention includes a plurality of sectioned fiber optic placed around and adjacent to the moveable object that transmits optical signals to a surface of the object and receives the optic signals when a predefined marker or a reflective area is sensed. Another embodiment utilizes a sectioned optical assembly which, via alternate means, produces equivalent optical measurements. The received optic signals are then processed using mathematical computations that are facilitated through pre-characterization of the sensor response against a reflective material identical to that of the marker or reflective area.

Abstract: An apparatus for determining the torque imposed on a rotatable shaft. The shaft has at least four paired probes, paired horizontal probes and paired vertical probes. The horizontal probes are positioned 90 degrees apart from the vertical probes. If the shaft moves horizontally, the time of arrival detected by the first horizontal probes will be later than a nominal value and the time of arrival for the second horizontal probes will be earlier than a nominal value with the same amount of error. Combining data from the first and second horizontal probes will then automatically cancel out any error from horizontal motion. Similarly, combining data from vertical probes will eliminate the error due to vertical movement. Because any radial movement is a combination of horizontal and vertical movements, the use of the probes removes errors due to movement in any direction.

Abstract: A device for mounting a sensor on a device being subjected to torque such as a shaft or plate in the form of a retaining ring having an opening or chamber sized to hold the sensor. The ring has a first open end for insertion of the sensor into the chamber or opening and a second end having a lip for retaining the sensor in the opening. The second end has an opening for the sensor wires or other connecting elements. The ring has threads on the outer periphery of the retaining ring for engaging similar threads on the device being subjected to torque.

Abstract: A drive for closure elements is provided, in particular in the area of garage and industrial doors, but also for example in the form of roller shutters, with a reference value generator arranged in the motor or in the gearing of the drive for determining the actual position of the closure element. When a reference point position is reached, the reference value generator emits a signal or causes a signal modification, on the basis of which the actual-value generator can be calibrated. The reference value generator has two reference discs rotating in different speeds, which, in predetermined angular positions to one another, define the reference point positions which can be scanned by at least one scanning device.

Abstract: Apparatus for applying torsional vibration to a rotating machine is provided. In one exemplary embodiment the apparatus includes a permanent magnet machine (12) connected to the rotating machine (22) and configured to generate a three-phase AC output voltage. A converter (36) may be coupled to receive the three-phase AC output voltage from the permanent magnet machine to supply a DC load current. An electrical load (44) (or exciter) may be coupled to the converter to receive the load current. An oscillator (42) is connected to the converter to provide an oscillation signal for modulating the load current from the converter. Modulated load current causes variable loading of the permanent magnet machine thereby creating an oscillatory torque in the permanent magnet machine (12). The oscillatory torque causes torsional vibration in the rotating machine. Various components of the apparatus for applying torsional vibration may be part of a field-deployed power generating system.

Abstract: Sensor systems and methods are disclosed herein, including a sensor chip, upon which at least two surface acoustic wave (SAW) sensing elements are centrally located on a first side (e.g., front side) of the sensor chip. The SAW sensing elements occupy a common area on the first side of the sensor chip. An etched diaphragm is located centrally on the second side (i.e., back side) of the sensor chip opposite the first side in association with the two SAW sensing elements in order to concentrate the mechanical strain of the sensor system or sensor device in the etched diagram, thereby providing high strength, high sensitivity and ease of manufacturing thereof.

Abstract: A torsional vibration measuring instrument has a plurality of reflecting means (6, 7) arranged with stipulated intervals along surface of a rotator (5) of which torsional vibration is to be measured; a pulse light irradiating means (1, 2) for irradiating a repetitive pulse light beam to the reflecting means; and an outgoing-transmitting means (3, 4) for transmitting the irradiated pulse light beam. The torsional vibration measuring instrument also has a plurality of transmitting-receiving means (8, 9) for irradiating the transmitted pulse light beam to the reflecting means, and for receiving reflected pulse light beams which have been reflected by the reflecting means; and an incoming-transmitting means (3, 4) for transmitting the reflected pulse light beams which have been received.

Abstract: A method and apparatus for detecting torsional vibration, or stick-slip, in a drill string while drilling is described. The method comprises sampling a downhole pressure sensor and using embedded filter schemes and algorithms to determine, based on the pressure samples, whether torsional vibration is occurring in the drill string. The method may also include sending a warning signal to the surface of the well. The apparatus comprises a downhole assembly having a downhole receiver and a master controller. The downhole receiver comprises a pressure sensor, filter schemes, and algorithms for detecting torsional vibration. The downhole assembly may also include a downhole transmitter for sending a warning signal to the surface of the well.

Abstract: An acoustic wave sensor utilizes one or more acoustic waves trapped in an acoustic wave cavity to detect the presence of one or more substances on a surface of the acoustic wave cavity. To detect the presence of ice, a trapped torsional acoustic wave is used. To detect water, an acoustic wave with flexural or compressional components is used. The sensor includes a number of transducers adjacent the acoustic wave cavity where a controller drives different sets of the transducers to generate different acoustic waves.

Abstract: The invention provides an improved method and device for inspecting heat exchanger tubes from within the tube inside diameter that overcomes the shortcomings of the prior art. It adapts a guided-wave probe approach that makes use of a torsional wave mode instead of a longitudinal wave node disclosed in the prior art. The torsional wave mode has many advantages over the longitudinal wave mode for detecting defects. When energized by suitable instrumentation, the probe is caused to generate a torsional mode signal that is transmitted to the heat exchanger tube from the waveguide tube. When reflected signals from defects in the heat exchanger tube walls are returned to the inspection opening end of the heat exchanger tube, the reflected defect signals are transmitted to the probe waveguide tube for amplification, detection and characterization of the reflected signal.

Abstract: Object of this invention is to provide an axial torsional vibration measurement device of the reactor internal pump capable of measuring the axial torsional vibration easily. The vibration detector 2 that detects vibration in the radial direction, and the sound detector 3 that detects vibration in the circumferential direction are fitted on cylindrical motor casing 6, which contains the motor of a reactor internal pump. The dimension of both signals of a vibration waveform signal detected by the vibration detector 2, and a sound waveform signal detected by the sound detector 3 are matched in vibration calculating device 15, to thereby obtain an axial torsion vibration of a motor from the difference of both signals.

Abstract: To conduct a fluid, the transducer has a flow tube which in operation vibrated by an excitation assembly. Inlet-side and outlet-side vibrations of the flow tube are sensed by means of a sensor arrangement. To produce shear forces in the fluid, the flow tube is at least intermittently excited into torsional vibrations about a longitudinal flow-tube axis. An internal portion of the transducer, formed at least by the flow tube, an antivibrator, the sensor arrangement, and the excitation assembly and mounted at least on the inlet and outlet tube sections, has a centroid which is located inside the flow tube. The transducer is suitable for use in viscometers or Coriolis mass flowmeter-viscometers. In spite of using only a single straight flow tube, it is dynamically well balanced in operation, and the development of bending moments by the torsionally vibrating flow tube is largely prevented. This also effectively prevents the transducer case or the connected pipe from being excited into sympathetic vibration.

Abstract: A device for detecting different conditions of a component, such as distorted conditions, movements and loaded conditions. Said device comprises a transmitter and a receiver which are located independently on at least one component at a distance from one another and an evaluation unit. The transmitter emits an electromagnetic wave (such as e.g. a laser beam), or a focused particle beam to the receiver. The spatial resolution can be increased by multiple reflections from a mirror and a semi-transparent mirror.

Abstract: A detector for monitoring rotation of a target includes a sensor unit, a microcontroller, and an operator conversation apparatus. The operator conversation apparatus is connected to the microcontroller and enables setting of the detector in a working mode or a learning mode.

Abstract: A method and system are provided for measurement of vibration of an object utilizing a non-contact imaging sensor such as a video camera. An object which does not already have a pair of spaced-apart marks is marked with two parallel lines spaced apart from one another a known, nominal distance. The two lines are perpendicular to an imaging axis of the camera. As such, when the object with the parallel lines is moved toward or away from the video camera, the lines on the object appear to move as two parallel lines in the image plane of the camera. As the object moves or vibrates along the imaging axis, the nominal image plane distance between the two lines changes. This apparent change in the distance between the parallel lines in the image plane is calibrated to the physical movement of the object in space due to deformation or rigid body motions.

Abstract: A multi-axis vibration sensor with integral magnet optimizes sensor response in a non-permanently attachable package. In a preferred embodiment of the invention, the apparatus includes a housing having a magnet, a multi-axis vibration sensor for sensing vibration along multiple machine axes, and conditioning circuitry disposed within the housing. The magnet enables the apparatus to be placed in sensory contact with the machine. The vibration sensor senses machine vibration along multiple machine axes when the apparatus is in sensory contact with the machine, and the conditioning circuitry optimizes the frequency response of the vibration sensor in a preferred embodiment by reducing the gain of the sensor output at resonance. The vibration sensor may be mounted directly to existing machine structure, such as the machine's outer casing. Two parallel feet facilitate stable mounting of the sensor to a curved surface.

Abstract: Object of this invention is to provide an axial torsional vibration measurement device of the reactor internal pump capable of measuring the axial torsional vibration easily. The vibration detector 2 that detects vibration in the radial direction, and the sound detector 3 that detects vibration in the circumferential direction are fitted on cylindrical motor casing 6, which contains the motor of a reactor internal pump. The dimension of both signals of a vibration waveform signal detected by the vibration detector 2, and a sound waveform signal detected by the sound detector 3 are matched in vibration calculating device 15, to thereby obtain an axial torsion vibration of a motor from the difference of both signals.

Abstract: A method and system for detecting drive train vibration. The system includes a programmable controller programmed to generate an output signal based on information from a wheel sensor located to sense the rotational behavior of an individual wheel. The controller is programmed to conduct a period test and a pattern test. A vibration of the drive train is detected in the event that both the period test and the pattern test are satisfied.

Abstract: A performance measuring system for a rotating shaft comprises a first annular support assembly to be coupled adjacent to a first end of a rotating shaft inwardly of associated shaft bearings. A second annular support assembly is to be coupled adjacent to a second end of a rotating shaft inwardly of associated shaft bearings. A third annular support assembly is to be coupled to the rotating shaft between the first and second support assemblies. A laser source is mounted on the first annular support assembly. A laser detector is mounted on the second annular support assembly. First and second magnetic sensors for detecting the Earth's magnetic field are mounted respectively on the first and second annular support assemblies. An accelerometer is mounted on the third annular support assembly for generating a fourth detection signal.

Abstract: To conduct a fluid, the transducer has a flow tube which in operation vibrated by an excitation assembly. Inlet-side and outlet-side vibrations of the flow tube are sensed by means of a sensor arrangement. To produce shear forces in the fluid, the flow tube is at least intermittently excited into torsional vibrations about a longitudinal flow-tube axis. An internal portion of the transducer, formed at least by the flow tube, an antivibrator, the sensor arrangement, and the excitation assembly and mounted at least on the inlet and outlet tube sections, has a centroid which is located inside the flow tube. The transducer is suitable for use in viscometers or Coriolis mass flowmeter-viscometers. In spite of using only a single straight flow tube, it is dynamically well balanced in operation, and the development of bending moments by the torsionally vibrating flow tube is largely prevented. This also effectively prevents the transducer case or the connected pipe from being excited into sympathetic vibration.

Abstract: The present invention relates to a miniature rheometer, a parallel rheometer, and improved force sensor elements which may advantageously be used in combination with the miniature rheometer and the parallel rheometer. The miniature rheometer is adapted to determine rheological characteristics of materials which are provided in the form of small quantity samples. The miniature rheometer comprises an actuating element, a sensing element and a feedback circuit to provide rebalance of the shear force applied by the sample to the sensing element, which insures an exceptional stiffness in determining the shear strain so as to allow measurements of high accuracy. The parallel rheometer of the present invention allows simultaneous measurements of a plurality of samples so as to allow of a plurality of samples within a short time period. The force sensor element according to the present invention allows simultaneous measurement of a shear force and a normal force applied to the sensor element.