A method to measure the vibrational characteristics of an oscillating system (1) uses a control system (6, 7a, 7b, 7c). The oscillating system comprises a resonator, at least one vibration exciter and at least one sensor. The resonator is excited by the vibration exciter, and the motion of the resonator is measured by the sensor. The control system uses the sensor to control the motion of the resonator by the vibration exciter. The motion of the resonator is a superposition of at least two harmonic motions, and the control system comprises at least two subcontrollers (7a, 7b, 7c). Each harmonic motion is controlled independently by one of the subcontrollers. The harmonic motions are controlled by the subcontrollers simultaneously. A corresponding device is also disclosed.

The present disclosure relates to devices and methods for determining the density of insulation (e.g., in a cavity). For example, one aspect of the disclosure is a device that includes a probe, an actuator, a sensor, and a control system. The control system is configured to cause the actuator to oscillate the probe. The sensor is configured to generate a signal that represents the density of insulation. Another aspect of the disclosure relates to a method for determining the density of insulation. The method includes placing a probe into contact with the insulation, causing, via an actuator, the probe to oscillate while in contact with the insulation, and generating, via a sensor, a signal that represents the density of insulation.

The present disclosure relates to devices and methods for determining the density of insulation (e.g., in a cavity). For example, one aspect of the disclosure is a device that includes a probe, an actuator, a sensor, and a control system. The control system is configured to cause the actuator to oscillate the probe. The sensor is configured to generate a signal that represents the density of insulation. Another aspect of the disclosure relates to a method for determining the density of insulation. The method includes placing a probe into contact with the insulation, causing, via an actuator, the probe to oscillate while in contact with the insulation, and generating, via a sensor, a signal that represents the density of insulation.

A method (600) of generating a drive signal for a vibratory sensor (5) is provided. The method (600) includes vibrating a vibratory element (104, 510) configured to provide a vibration signal, receiving the vibration signal from the vibratory element (104, 510) with a receiver circuit (134), generating a drive signal that vibrates the vibratory element (104, 510) with a driver circuit (138) coupled to the receiver circuit (134) and the vibratory element (104, 510), and comparing a phase of the generated drive signal with a phase of the vibration signal.

A method (600) of generating a drive signal for a vibratory sensor (5) is provided. The method (600) includes vibrating a vibratory element (104, 510) configured to provide a vibration signal, receiving the vibration signal from the vibratory element (104, 510) with a receiver circuit (134), generating a drive signal that vibrates the vibratory element (104, 510) with a driver circuit (138) coupled to the receiver circuit (134) and the vibratory element (104, 510), and comparing a phase of the generated drive signal with a phase of the vibration signal.

A system includes a particulate material sample that contains a fluid medium and a plurality of particles dispersed in the fluid medium. The system further includes a particle analysis apparatus having a sample cell and sample delivery means for delivering the particulate material sample to the sample cell, wherein the particle analysis apparatus is adapted to obtain particle information on at least one particle in that particulate material sample while the at least one particle is in the sample cell. Furthermore, the system also includes fluid manipulation means for manipulating movement of the fluid medium while the particle analysis apparatus is obtaining the particle information on the at least one particle, and a data processing apparatus that is adapted to determine a specific gravity of the at least one particle based on the obtained particle information.

A system includes a particulate material sample that contains a fluid medium and a plurality of particles dispersed in the fluid medium. The system further includes a particle analysis apparatus having a sample cell and sample delivery means for delivering the particulate material sample to the sample cell, wherein the particle analysis apparatus is adapted to obtain particle information on at least one particle in that particulate material sample while the at least one particle is in the sample cell. Furthermore, the system also includes fluid manipulation means for manipulating movement of the fluid medium while the particle analysis apparatus is obtaining the particle information on the at least one particle, and a data processing apparatus that is adapted to determine a specific gravity of the at least one particle based on the obtained particle information.

A method of initiating a fluid density measurement includes generating a prime resonance of a test fixture by a startup circuit. The method of initiating a fluid density measurement includes closing a feedback loop in response to generating the prime resonance. The method of initiating a fluid density measurement includes maintaining the prime resonance by closing the feedback loop.

A method of initiating a fluid density measurement includes generating a prime resonance of a test fixture by a startup circuit. The method of initiating a fluid density measurement includes closing a feedback loop in response to generating the prime resonance. The method of initiating a fluid density measurement includes maintaining the prime resonance by closing the feedback loop.

A system composed of a servicing device and a field device having at least one sensor unit for determining and/or monitoring at least one process variable. At least one electronics unit, which has an evaluation unit, wherein the evaluation unit receives measurement signals from the sensor unit and evaluates such with reference to the process variable, and at least one switch element actuatable contactlessly from outside of the field device. The servicing device is embodied to modulate the switch state of the switch element for transmission of field device specific data to the electronics unit. Furthermore, a field device, a servicing device and a method for communication between field device and servicing device are claimed.