A gas sensor having a heater, a receiver, and a space arranged between the heater and the receiver, is described, the heater being configured to generate a thermoacoustic sound wave propagating through the space by using a stimulation signal. The receiver is in this case configured to receive the thermoacoustic sound wave that has propagated through the space and to convert it into a reception signal that has a time-of-flight-dependent shift with respect to the stimulation signal and therefore information relating to the gas concentration in the space.

A humidity sensor includes a sound wave element configured to transmit a sound wave and receive the sound wave reflected by a reflector, a reception circuit configured to obtain an arrival time of the reflected wave received by the sound wave element, and a humidity analysis circuit configured to calculate humidity by using the arrival time, a distance from the sound wave element to the reflector, and a temperature of a space from the sound wave element to the reflector.

A device including at least one sensing bulk acoustic wave (BAW) resonator including a sensing surface; a fluid channel, wherein the sensing surface of the at least one sensing BAW resonator is disposed adjacent to or within the fluid channel; at least one resistive heater; and at least one temperature detector, wherein the at least one temperature detector is configured to monitor the temperature adjacent to the at least one BAW resonator and affect a current to be passed through the at least one resistive heater.

A gas sensor comprises a membrane, a first plate arranged on a first side of the membrane and having through openings for the passage of a gas, a second plate arranged on a second side of the membrane, the second side being situated opposite the first side, and an electronic circuit, which is connected to the membrane, the first plate and the second plate and causes the membrane to emit ultrasonic radiation, and which is configured to determine a resonant frequency of the ultrasonic radiation.

A fluid sensor includes a tuning fork mechanical resonator including a base and a tine projecting from the base along a longitudinal direction of the tine, and a pair of electrodes disposed on the tine. The base and the tine are formed from a piezoelectric material including lithium tantalate. The electrodes are exposed to a fluid.

A methods and systems for determining a change in condition of a rock bolt. Some methods may comprise, at a first point in time, propagating shear and longitudinal ultrasonic waves along the rock bolt to measure a first time of flight for each of the shear and longitudinal waves, at a second point in time after the first point in time, propagating shear and longitudinal ultrasonic waves along the rock bolt to measure a second time of flight for each of the shear and longitudinal waves, and using the relative changes of the first and second time of flights, determining the change in condition of the rock bolt section.

A substance sensor includes sensitive membranes to react with substances included in the odors of a gas in correspondence with the substances, and is configured to detect the reaction values of the sensitive membranes. An odor specifier specifies the odors of the gas on the basis of the reaction values of the sensitive membranes. A reaction value calculator calculates reaction values corresponding to the odors specified by the odor specifier on the basis of the reaction values of the sensitive membranes. A percentage calculator calculates the percentages of the reaction values corresponding to the odors specified by the odor specifier to the total of the reaction values corresponding to the odors. A display displays the percentages of the reaction values corresponding to the odors, calculated by the percentage calculator, so that comparison of the percentages is enabled between the odors specified by the odor specifier.

Systems, methods, and apparatus for tracking location of an inspection robot are disclosed. An example apparatus for tracking inspection data may include an inspection chassis having a plurality of inspection sensors configured to interrogate an inspection surface, a first drive module and a second drive module, both coupled to the inspection chassis. The first and second drive module may each include a passive encoder wheel and a non-contact sensor positioned in proximity to the passive encoder wheel, wherein the non-contact sensor provides a movement value corresponding to the first passive encoder wheel. An inspection position circuit may determine a relative position of the inspection chassis in response to the movement values from the first and second drive modules.

Embodiments herein provide a method and system for a non-invasive mechanism providing simultaneous determination of viscosity-temperature variation of a lubricant for predicting machine health using a Photo Acoustic (PA) sensing mechanism, Laser-enabled swept frequency acoustic interferometry (LE-SFAI), wherein the lubricant produces acoustic wave only if it absorbs the laser irradiation, thus overcomes the limitation of ultrasound based SFAI through optical absorption based contrast and proper selection of laser excitation wavelength. A PA signal received from the lubricant is processed by a Vector Network Analyzer (VNA), then converted to time domain to obtain normalized first peak that corresponds to the PA signal generated by the lubricant. A squared rise time of the first peak is indicative of viscosity of the liquid and shift in the first peak is indicative of variation of the viscosity as temperature of the lubricant varies.

The present disclosure provides a system and method for real-time visualization of a material during ultrasonic non-destructive testing. The system includes a graphical user interface (GUI) capable of showing a three-dimensional (3-D) image of a composite laminate constructed of a series of two-dimensional (2-D) cross sections. The GUI is capable of displaying the 3-D image as each additional 2-D cross section is scanned by an ultrasonic testing apparatus in real time or near real time, including probable defect regions that contain a flaw such as a hole, crack, wrinkle, or foreign object within the composite. Furthermore, in one embodiment, the system includes an artificial intelligence capable of highlighting defect areas within the 3-D image in real time or near real time and providing data regarding each defect area, such as the depth, size, and/or type of each defect.