A device for wireless detection of a BTEX component in a soil saturated with water, comprising an antenna, a permeable enclosure, and a sensor located in the enclosure. The sensor comprises: a piezoelectric substrate comprising lithium tantalate, an interdigitated transducer connected to the antenna for producing surface acoustic waves, a first mirror for a first echo of the acoustic waves, a second mirror for producing a second echo, a first layer of a first polymer between the transducer and the second mirror, the first polymer being adapted for reacting with the BTEX component so as to modify a travel speed of the second echo, and a first guiding layer comprising a metal and/or a polymer and located between the transducer and the first mirror.

Methods, systems, devices, and products for evaluating a downhole fluid in a borehole intersecting an earth formation. Methods include using ultrasonic irradiation to produce sonoluminescence from cavitation in a volume of the fluid; obtaining spectral information from measurement of the sonoluminescence with a light-responsive device; and estimating a parameter of interest of the fluid from the spectral information. The parameter may be a composition of the fluid or concentration of: i) at least one chemical element in the volume; i) at least one molecular element in the volume. Methods include deconvolving a response spectrum by using one or more separately determined standard spectra, or estimating the parameter of interest using spectral lines represented by the spectral information. Methods may include using an optically transparent ultrasonic transducer to produce the cavitation at the interface of the transducer, with optically transparent ultrasonic transducer between the interface and the light-responsive device.

Ultrasound tomography arrays and vortex shedding devices are provided which measure average flow velocity through Doppler shift of the fluid as well as cross sectional multiphase fluid composition in pipe or tubing conduits. Multiple tomographic arrays in conjunction with correlation of sensed flow patterns in time provided determination of flow velocity as well as cross sectional multiphase fluid composition. The tomographic arrays may be arranged in a skewed or slanted plane to measure velocity fluctuations downstream of a vortex shedding device where the period and amplitude of the fluctuations is correlated with the mass flow of the fluid. Additionally, the tomographic arrays provide the relative composition of the multiphase fluid. The multiple arrays together with correlation to determine velocity fluctuations downstream of a vortex shedding device where the period and amplitude of the fluctuations is correlated with the mass flow of the fluid. Additionally the tomographic arrays output the relative composition of the multiphase fluid.