An apparatus for measuring a viscosity of a fluid is disclosed. The apparatus includes a Parylene coated quartz tuning fork for immersion in the fluid and an electronic circuit to excite a vibration of the Parylene coated quartz tuning fork and measure one or more vibrational parameters of the Parylene coated quartz tuning fork. A computer processor is configured to determine a non-Newtonian viscosity from the vibration of the Parylene coated quartz tuning fork based, at least in part, on a Stokes flow hydrodynamic model. The computer processor is coupled to a memory for storing a calibration curve to determine a Newtonian viscosity of the fluid from the non-Newtonian viscosity of the fluid.

There are provided a viscometer that can accurately measure a bulk viscosity of a small amount of a liquid sample such as 100 μL or less, and a method for measuring viscosity. A viscometer (1) comprises a fixing member (31), an upper unit (10), a lower unit (11), and an information processing unit (50). A method for measuring viscosity comprises measuring a viscosity of the sample by measuring a response voltage during resonance from a detecting means (19) that detects displacement of a leaf spring (17) in one direction due to vibration of the upper unit (10) through applying an AC voltage to a piezoelectric element (15) while changing a frequency by the information processing unit (50).

Techniques for determining rheological properties of a fluid include actuating a resonator disposed in a volume that contains a fluid sample to operate the resonator in the fluid sample at a predetermined actuation scheme; measuring at least one characteristic of the resonator based on the operation of the resonator in the fluid sample; comparing the at least one measured characteristic to a rheological model that associates characteristics of the fluid sample to one or more rheological properties; and based on the comparison, determining one or more rheological properties of the fluid sample.

A vibronic sensor used to determine a process variable of a medium in a container comprises a mechanically vibratable unit, a drive/receiving unit, and an electronic unit. The drive/receiving unit excites mechanical vibrations in the mechanically vibratable unit via an electric excitation signal and receives the mechanical vibrations of the mechanically vibratable unit and convert same into an electric reception signal. The electronic unit is designed to generate the excitation signal on the basis of the reception signal and determine the process variable from the reception signal. The electronic unit includes an adaptive filter and is designed to set the filter characteristic of the adapter filter to produce a target phase offset between the excitation and reception signals. The sensor also has a detection unit to determine a phase offset between the excitation signal and the reception signal and/or the amplitude of the reception signal using a quadrature demodulation.

A vibronic sensor used to determine a process variable of a medium in a container comprises a mechanically vibratable unit, a drive/receiving unit, and an electronic unit. The drive/receiving unit excites mechanical vibrations in the mechanically vibratable unit via an electric excitation signal and receives the mechanical vibrations of the mechanically vibratable unit and convert same into an electric reception signal. The electronic unit is designed to generate the excitation signal on the basis of the reception signal and determine the process variable from the reception signal. The electronic unit includes an adaptive filter and is designed to set the filter characteristic of the adapter filter to produce a target phase offset between the excitation and reception signals. The sensor also has a detection unit to determine a phase offset between the excitation signal and the reception signal and/or the amplitude of the reception signal using a quadrature demodulation.

A method is provided to measure viscosity of an analyte using a microfluidic piezoelectric sensor including a channel on an active area of a piezoelectric resonator substrate. The microfluidic piezoelectric sensor is driven so that the active area of the piezoelectric resonator substrate generates shear motion in a direction of shear motion displacement that is parallel with respect to a first surface of the piezoelectric resonator substrate. A high shear-rate viscosity of the analyte is determined based on a shift in resonance of the microfluidic piezoelectric sensor while driving the microfluidic piezoelectric sensor with the analyte in the channel. A low shear-rate viscosity of the analyte is determined by detecting flow of the analyte through the channel based on tracking shifts in resonance of the microfluidic piezoelectric sensor. Related sensors are also discussed.

A method is provided to measure viscosity of an analyte using a microfluidic piezoelectric sensor including a channel on an active area of a piezoelectric resonator substrate. The microfluidic piezoelectric sensor is driven so that the active area of the piezoelectric resonator substrate generates shear motion in a direction of shear motion displacement that is parallel with respect to a first surface of the piezoelectric resonator substrate. A high shear-rate viscosity of the analyte is determined based on a shift in resonance of the microfluidic piezoelectric sensor while driving the microfluidic piezoelectric sensor with the analyte in the channel. A low shear-rate viscosity of the analyte is determined by detecting flow of the analyte through the channel based on tracking shifts in resonance of the microfluidic piezoelectric sensor. Related sensors are also discussed.

A device for determining and/or monitoring a process variable of a medium includes a sensor unit having a mechanically oscillatable unit, a first piezoelectric element, a unit for determining and/or monitoring a temperature of the medium and an electronic system. The device is designed to excite the mechanically oscillatable unit and to receive the mechanical oscillations of the oscillatable unit, to convert them into a first receiving signal, to emit a transmission signal and to receive a second receiving signal, wherein the electronic system is designed to determine the process variable based on the first and/or second receiving signal. The unit for determining and/or monitoring the temperature includes a first and a second temperature sensor arranged at a distance from one another, and the electronic system is designed to determine the temperature of the medium based on a first and/or second temperature receiving signal.

The invention provides a viscometer and an operation method thereof. The viscometer comprises a disk and at least one microfluidic structure. The microfluidic structure is embedded in the disk and has a first chamber which is connected to a second chamber. The second chamber is provided with an annular chamber along the circumferential direction of the disk and comprises at least one indicator. Overall, the present viscometer and its operation method do utilize the oscillation amplitude of pendulum motion of the indicator to calculate a viscosity value (cP) of a sample which has already existed in the second chamber.

The invention provides a viscometer and an operation method thereof. The viscometer comprises a disk and at least one microfluidic structure. The microfluidic structure is embedded in the disk and has a first chamber which is connected to a second chamber. The second chamber is provided with an annular chamber along the circumferential direction of the disk and comprises at least one indicator. Overall, the present viscometer and its operation method do utilize the oscillation amplitude of pendulum motion of the indicator to calculate a viscosity value (cP) of a sample which has already existed in the second chamber.