In the present invention a controllable acoustic source (14) in connection with the process fluid (10) emits a signal (18) into the fluid (10), consisting of a suspension of particles (12), being volumes of gas, liquid or solid phase. The controllable acoustic signal (18) is allowed to interact, with the particles (12), and the acoustic (pressure) signals (22) resulting from such an interaction is measured preferably via a sensor (24). A spectrum is measured. The spectrum is used to predict properties, content and/or size of the particles (12) and/or used to control a process in which the process fluid (10) participates. The prediction is performed in the view of the control of the acoustic source (14). The used acoustic signal has preferably a frequency below 20 kHz.

A method of detecting a vibration node between a non-collocated sensor-actuator pair of a rotatable component includes applying an excitation signal to an actuator of the sensor actuator pair. The method also includes obtaining frequency response data from the sensor-actuator pair. The method further includes analyzing the frequency response data to ascertain a resonant frequency of the rotatable component. The method includes identifying a resonance/anti-resonance peak pair in the frequency response data for the non-collocated sensor-actuator pair. Furthermore, the method includes determining whether the vibration node is located between a sensor and the actuator of the non-collocated sensor-actuator pair based on the resonance/anti-resonance peak pair.

A detection system 1 contains a sensing device 10 including a vibration unit 11 for applying vibration to the inspection target 100, the vibration unit 11 attached to the inspection target 100, a driving circuit 12 for supplying an electric signal to the vibration unit 11 for driving the vibration unit 11 and a sensor 13 for detecting vibration of the inspection target 100 caused by the vibration applied from the vibration unit 11; and a detection processing device 20 for receiving vibration information related to the vibration of the inspection target 100 detected by the sensor 13 from the sensing device 10 and detecting the state change of the inspection target 100 based on the vibration information. The vibration unit 11 includes a coil 112, a spring 113, and a magnet 114b.

Disclosed are an apparatus for detecting pipe wall thinning, which measures a natural frequency of a pipe and determines a level of the pipe wall thinning, and a method thereof. The apparatus for detecting the pipe wall thinning includes a hitting member 10 for hitting the pipe T, a vibration measurement sensor 20 which measures a vibration signal generated when the pipe T is hit with the hitting member 10, and a control part 30 which compares the natural frequency calculated from the vibration signal measured from the vibration measurement sensor 20 with a natural frequency generated from a normal pipe in which wall thinning does not occur, and determines the level of the wall thinning of the pipe T.

A through hole (3) is provided on a supporting substrate (2). A plate-shaped beam (4) extends from an edge of the through hole (3) to a facing edge in such a way as to cover part of the through hole (3) and is provided with a piezoelectric element. A drive electrode (16) vibrates the beam (4) by applying voltage to the piezoelectric element. Detection electrodes (17A, 17B) detect information about the vibration frequency of the beam (4). Substance adsorption films (5A, 5B) change the vibration frequency of the beam (4) by adhesion of a substance. The substance adsorption films (5A, 5B) and the detection electrodes (17A, 17B) are respectively provided at the same position on the front and the back of the beam (4).

An ultrasound sub-surface probe microscopy device (1) is provided comprising a stage (10), a signal generator (20), a scanning head (30), a signal processor (50) and a scanning mechanism (16). In use, the stage (10) carries a sample (11) and the scanning M mechanism (16) provides for a relative displacement between the sample (11) and the scanning head (30), along the surface of the sample. The scanning head (30) comprises an actuator (31) configured to generate in response to a drive signal (S.sub.dr) from the signal generator (20) an ultrasound acoustic input signal (I.sub.ac). The generated ultrasound acoustic input signal (I.sub.ac) has at least one acoustic input signal component (I.sub.ac1) with a first angular frequency (ω1). The scanning head (30) further comprises a tip (32) to transmit the acoustic input signal (I.sub.ac) through a tip-sample interface (12) as an acoustic wave (W.sub.ac) into the sample. Due to a non-linear interaction in the tip-sample interface (12) at least one up mixed acoustic signal component (W.sub.ac2) in said acoustic wave that has a second angular frequency (ω2) higher than the first angular frequency (ω1) Contrary to known approaches, the sensor signal (S.sub.sense) provided by the sensor facility is indicative for a contribution (W′.sub.ac2) of the at least one up mixed acoustic signal component in reflections (W′.sub.ac) of the acoustic wave within the sample (11). Therewith a relatively high resolution can be achieved with which subsurface features can be detected.

[Object] To provide an arithmetic device, an arithmetic method, and a gas detection system that are capable of easily correcting deterioration over time of a detection element.

[Solving Means] The arithmetic device includes a calculation unit. The calculation unit calculates a correction coefficient from a detection element that causes a resonant frequency change by adsorption of gas on the basis of a resonant frequency change amount associated with a humidity change of the detection element in a degraded state and a resonant frequency change amount associated with a humidity change of the detection element in an initial state that was acquired in advance, and corrects the resonant frequency change amount of the detection element in the degraded state by using the correction coefficient.

A method of manipulating and/or investigating cellular bodies (9) is provided. The method comprises the steps of: providing a sample holder (3) comprising a holding space (5) for holding a fluid medium (11); providing a sample (7) comprising one or more cellular bodies (9) in a fluid medium (11) in the holding space (5); generating an acoustic wave in the holding space exerting a force (F) on the sample (7) in the holding space (5). The method further comprises providing the holding space (5) with a functionalised wall surface portion (17) to be contacted by the sample (7) and the sample (7) is in contact with the functionalised wall surface portion (17) during at least part of the step of application of the acoustic wave. A system and a sample holder (3) are also provided.

A cartridge for sample handling and sensing includes (i) a sample port; (ii) a first fluid port connected to the sample reservoir in the distal region via a first fluid channel; and (iii) a second fluid port connected to the sample reservoir via a second fluid channel. The cartridge includes (i) a sensor platform comprising a bulk acoustic wave (BAW) resonator and a fluid flow path comprising a sensing region extending across a sensing surface of the BAW resonator; and (ii) a fluid valve between the sample reservoir and the sensing region. A sample may be applied to the sample port; first volume of fluid may be injected through the first fluid port; and then a second volume of fluid may be injected through the second fluid port to drive the sample into the sensing region of the fluid flow path.

Embodiments of the disclosure provide systems and methods for detecting a resonant frequency of an optical beam-steering device. The method may include driving the optical beam-steering device with a driving signal oscillating at a plurality of frequencies. The method may also include detecting, by an acoustic detector, an acoustic signal caused by a movement of the optical beam-steering device. The method may further include analyzing a spectrum, by a controller, of the acoustic signal. The method may additionally include determining, by the controller, the resonant frequency of the optical beam-steering device based on the spectrum.