When frequencies used in the two-frequency measurement of a SAW sensor are represented by f.sub.1 and f.sub.2 (f.sub.2>f.sub.1), an electrical signal processing device is provided without use of oversampling at a frequency higher than twice the frequency f.sub.2 or a two-system low-frequency conversion circuit, in which temperature compensation with the same accuracy as the case where these are used can be realized. Narrow band frequency filtering is applied to a waveform after roundtrips in a delay line type SAW sensor capable of transmitting and receiving multiple frequencies, the two frequencies f.sub.1 and f.sub.2 (f.sub.2>f.sub.1) are extracted, and a delay time is determined utilizing an aliasing obtained by applying undersampling at a frequency lower than twice the frequency f.sub.1.

A sensing system includes: a surface acoustic wave sensor with a first surface acoustic wave device-and a second surface acoustic wave device; a sensing apparatus detecting an electrical characteristic of the first and second surface acoustic wave devices connected to the surface acoustic wave sensor; and a control apparatus calculating a physical quantity acting on one of a target to which the surface acoustic wave sensor is attached and the surface acoustic wave sensor. The sensitivity ratio of a first physical quantity and the sensitivity of a second physical quantity are different, and a third physical quantity is removable by averaging. The control apparatus removes the first physical quantity based on the results of a comparison operation on sensor signals from the first and second surface acoustic wave elements, uses the averaging process to remove the third physical quantity, and thereby calculates the second physical quantity.

There are provided an analyte sensor and an analyte sensing method which provide measurements in a wide phase range, a reduction in size, and lowering of current consumption. That is, in an analyte sensor and an analyte sensing method, a detection element which outputs a detection signal in accordance with a change in mass in a detection portion and a reference element which outputs a reference signal in accordance with a change in mass in a reference portion are provided, a phase change value is determined from the detection signal and the reference signal by heterodyne system, and an amount of detection of a target is calculated.

In some embodiments, processes for testing for structural flaws in sapphire parts such as display cover plates used in the manufacturing of electronic devices are disclosed. A process may include transmitting a destructive acoustic signal onto a sapphire part, and determining whether the sapphire part failed in response to the destructive signal. The destructive acoustic signal may include a Rayleigh acoustic wave, wherein the destructive acoustic signal breaks the sapphire part if the sapphire part has a surface flaw larger than a specified size. In this manner, only sapphire parts that can withstand the destructive acoustic signal are used in manufacturing of the electronic device.

A method of detecting inconsistencies in a structure is presented. A pulsed laser beam is directed towards the structure. A plurality of types of ultrasonic signals is formed in the structure when radiation of the pulsed laser beam is absorbed by the structure. The plurality of types of ultrasonic signals is detected to form data.

A surface acoustic wave resonant sensor for measuring a sample comprising a single port surface acoustic wave (SAW) resonator comprising an interdigital transducer and at least one reflective grating. The sensor is provided with a region for receiving the sample, said region being in communication with the at least one reflective grating and the IDT is separated acoustically and electrically from the region for receiving a sample such that the IDT is not mass sensitive to the sample. The sensor is especially suitable for bio sensing applications.

Disclosed are methods for determining and classifying aircraft air contaminants comprising one or more of: turbine engine oil, hydraulic fluid and deicing fluid using contaminant analyzers comprising a contaminant collector comprising a membrane and a heater vaporizing the contaminants; a gravimetric sensor generating a response when contaminant mass is added to or removed from the sensor, the sensor receiving contaminants desorbed from the heated membrane; a frequency measurement device, measuring the response generated by the sensor as the contaminant is added to and removed from the sensor; a computer readable medium bearing a contaminant recognition program and calibration data; a processor executing the program, the program including a module classifying contaminants by type, and a module using the data for comparison with magnitude of response generated by the sensor to calculate contaminant concentration; and, a pump, generating flow of air through the collector before and after the membrane is heated.

A surface acoustic wave (SAW) sensor includes a surface acoustic wave material and a comb-teeth electrode. The surface acoustic wave material is to be arranged at a place where the surface acoustic wave material is distorted by physical quantity such as stress. The comb-teeth electrode is arranged on the surface of the surface acoustic wave material to excite a surface acoustic wave to the surface acoustic wave material. The surface acoustic wave material has a sapphire board and a ScAlN film arranged on a surface of the sapphire board.

An acoustic device for inspection of an object. The device includes an ultrasonic source including a snap-through buckling actuator. The device may be used for non-destructive testing of objects. The device may be carried by a platform, such as a coordinate measuring machine, to allow inspection of objects or it may be embedded within an object for life cycle monitoring purposes.

A sensor apparatus includes: an element substrate; a detecting section disposed on an upper surface of the element substrate, the detecting section including a reaction section having an immobilization film to detect an analyte; a first IDT electrode configured to generate an acoustic wave which propagates toward the reaction section, and a second IDT electrode configured to receive the acoustic wave which has passed through the reaction section; and a protective film located on the upper surface of the element substrate so as to cover the first IDT electrode, the second IDT electrode, and at least part of the immobilization film, the protective film extending between and contacting with the immobilization film and at least one of the first IDT electrode and the second IDT electrode.