A method of detecting at least a blockage status in a porous member separating a measurement chamber of a device including a gas sensor positioned within the measurement chamber which is responsive to an analyte in an ambient environment to be sampled, includes emitting pressure waves from a pressure wave source which travel within the measurement chamber, measuring a first response via a first sensor responsive to pressure waves positioned at a first position within the measurement chamber, measuring a second response via a second sensor at a second position, different from the first position, and in fluid connection with the pressure wave source, determining the blockage status of the porous member based upon a functional relation of the first response and the second response.

A method of detecting at least a blockage status in a porous member separating a measurement chamber of a device including a gas sensor positioned within the measurement chamber which is responsive to an analyte in an ambient environment to be sampled, includes emitting pressure waves from a pressure wave source which travel within the measurement chamber, measuring a first response via a first sensor responsive to pressure waves positioned at a first position within the measurement chamber, measuring a second response via a second sensor at a second position, different from the first position, and in fluid connection with the pressure wave source, determining the blockage status of the porous member based upon a functional relation of the first response and the second response.

A light emitting unit irradiates a measurement site of a measurement subject with a light beam having a wavelength that is absorbed by a measurement target substance. A detection unit detects a photoacoustic signal generated in the measurement site irradiated with the light beam emitted from the light emitting unit. A resonator is arranged so as to clamp the measurement site, and causes the above-described photoacoustic signal to resonate. The resonator is constituted by a first reflection unit and a second reflection unit. The first reflection unit is arranged between the light irradiation unit and the measurement site. Also, the light beam passes through the first reflection unit. The second reflection unit is arranged between the detection unit and the measurement site.

A method for structural component crack testing comprising: a) identifying a structural component hole and inserting a probe thereinto; b) for different emission directions, automatically performing the following: b1) controlling a probe ultrasound beam emission; b2) measuring a probe signal; b3) if the measured signal amplitude is above a predetermined threshold: determining a distance between the probe and a structural component discontinuity point; recording a data set comprising at least the distance between the probe and the discontinuity point, together with a data element corresponding to the probe emission angular direction, c) automatically searching for data sets corresponding to characteristic discontinuity points, and consequently establishing a correspondence between the probe emission angular directions and an angular reference frame linked to the component; d) based on the recorded data sets, automatically determining the discontinuity point positions; e) determining a dimensional characteristic of a crack based on the discontinuity point positions.

An impact detection methodology is disclosed. Systems and methods can be utilized to detect impacts of concern such as collisions, falls, or other incidents. Systems and methods can be utilized to monitor an area and detect falls or collisions of an individual, for instance, as may require intervention to aid the subject. A system can include two or more accelerometers and a controller. The accelerometers can be in communication with the structure (e.g., within or on the walls or floor of a structure) and can monitor the structure for vibrations. The accelerometers can be coupled to a controller that is configured to process data obtained from the accelerometers and provide output with regard to the force and/or location of an impact within the structure.

An impact detection methodology is disclosed. Systems and methods can be utilized to detect impacts of concern such as collisions, falls, or other incidents. Systems and methods can be utilized to monitor an area and detect falls or collisions of an individual, for instance, as may require intervention to aid the subject. A system can include two or more accelerometers and a controller. The accelerometers can be in communication with the structure (e.g., within or on the walls or floor of a structure) and can monitor the structure for vibrations. The accelerometers can be coupled to a controller that is configured to process data obtained from the accelerometers and provide output with regard to the force and/or location of an impact within the structure.

A method of determining a status of ultrasound coupling medium for performing an ultrasound scan for providing an ultrasound image including plural scanlines (N.sub.l) is disclosed. In an embodiment, the method includes operating an ultrasound device to capture an image frame including plural scanlines (N.sub.l), each scanline having an associated sample set (s) of intensity values; processing a subset of the associated sample set (s) of values for each scanline to determine a first summation for each scanline; processing plural sets of corresponding intensity values from each of plural scanlines located within a range of a respective scanline to determine a set of difference values for each respective scanline; processing each set of difference values to determine a second summation for each scanline; and generating a status for the ultrasound coupling medium according to a relationship between each of the first summations and each of the associated second summations.

The invention discloses a non-linear Lamb wave mixing method for measuring stress distribution in thin metal plates. The method is suitable for stress distribution detection and stress concentration area positioning in a plate structure and belongs to the field of nondestructive detection. The steps of the present invention is: first determines the excitation frequencies of two fundamental waves according to the measured object and the nonlinear Lamb wave mixing resonance conditions; the left and right ends of the test piece are oppositely excited two rows of A0 mode waves, and the excitation signal receive the sum-frequency S0 signal at a certain position to detect non-linear mixing stress of the plate structure; by changing the excitation time delay of the excitation signal, perform mixing scan on different positions of the test piece to extract the mixing wave amplitude; finally, according to the variation of amplitude of sum frequency difference signal with mixing position to realize the detection of stress distribution of metal plate and the positioning of the stress concentration area.

A method for detecting of components in a fluid includes emitting a modulated light beam from a modulated light source to the fluid in a chamber, wherein the fluid comprises a liquid and a component in the liquid. The method includes producing an acoustic signal in response to the emitted modulated light beam and detecting the acoustic signal via a pressure sensor disposed in the chamber. The method in one example also includes transmitting the acoustic signal from the pressure sensor to a processor based module and determining at least one of a component and a concentration of the component in the fluid via the processor based module, based on the acoustic signal.

A method for detecting of components in a fluid includes emitting a modulated light beam from a modulated light source to the fluid in a chamber, wherein the fluid comprises a liquid and a component in the liquid. The method includes producing an acoustic signal in response to the emitted modulated light beam and detecting the acoustic signal via a pressure sensor disposed in the chamber. The method in one example also includes transmitting the acoustic signal from the pressure sensor to a processor based module and determining at least one of a component and a concentration of the component in the fluid via the processor based module, based on the acoustic signal.