Systems and methods for non-invasively determining a water content, a solute content, and a thickness of plant tissue are disclosed. A system includes a sensing device having a first piece and a second piece, where the first piece and the second piece are coupled together to form a clip. The system further includes a capacitive tissue sensor including a capacitor. The capacitor includes a plurality of coplanar conductive plates. The first piece and the second piece are biased in a closed position to provide a gripping force around the plant tissue such that at least a portion of the plant tissue contacts the plurality of coplanar conductive plates.

Systems and methods for corrosion detection of downhole tubulars. A method may include disposing an electromagnetic logging tool in a wellbore, wherein the electromagnetic logging tool may comprise a transmitter and a receiver; making a first measurement with the electromagnetic logging tool in a first nominal section of the wellbore, wherein the first nominal section may comprise M pipes, wherein M may be a number of pipes positioned in the first nominal section; making a second measurement with the electromagnetic logging tool in a second nominal section of the wellbore, wherein the second nominal section may comprise N pipes, wherein N may be a number of pipes in the second nominal section, wherein N may be different than M; calculating a phase difference between the first and second measurements; calculating a thickness difference between the first and second measurements; calculating a first slope from at least the phase difference and the thickness difference; making a third measurement in a non-nominal section of the wellbore; and calculating a thickness associated with a depth of the third measurement using at least the first slope and the third measurement.

Systems and methods for reducing effects of pipe couplings in electromagnetic log data. A method for corrosion detection comprises disposing an electromagnetic logging tool within a plurality of concentric pipes in a wellbore; obtaining electromagnetic log data along the concentric pipes; and identifying a location of at least one pipe coupling on at least one of the concentric pipes; and processing the electromagnetic log data to determine one or more attribute of the concentric pipes as a function of depth, wherein the processing uses the location of at least one pipe coupling to account for effect of the at least one pipe coupling on the electromagnetic log data.

A method includes introducing a pipe inspection tool into a first pipe positioned within a wellbore and further positioned within at least a second pipe. The pipe inspection tool includes an electromagnetic sensor having a coil antenna that includes a coil winding extending axially along at least a portion of the electromagnetic sensor. An excitation signal is transmitted between a first terminal and a second terminal of the coil antenna. A first response signal is measured between a third terminal and a fourth terminal of the coil antenna, wherein at least one of the third and fourth terminals is different from the first and second terminals. The first response signal is then processed to determine a characteristic of the first pipe.

Methods, systems, and computer program products for inspecting a pipe in a well using an eddy-current based pipe inspection tool comprises conveying the pipe inspection tool through the well, obtaining a first voltage measurement at an axial position along the pipe from at least one main receiver. The first voltage measurement includes a residual voltage induced in the at least one main receiver by a residual magnetic field resulting from residual magnetism in the pipe. A second voltage measurement is obtained at said axial position along the pipe from at least one second receiver. The first voltage measurement and the second voltage measurement are processed to obtain a processed measurement representing a difference between the first and second voltage measurements. The processed measurement is substantially free of the residual voltage and may be use to estimate a thickness of the pipe and other pipe characteristics.

Systems and methods for detecting corrosion under insulation are disclosed herein. In one embodiment, an apparatus for detecting corrosion in an object includes an electrically conductive excitation unit disposed around the object, and a source of electrical power connected to the excitation unit. The source of electrical power causes an alternating current in the excitation unit. The apparatus also includes a carrier that carries the excitation unit, and a magnetic sensor unit that is carried by the carrier or by the excitation unit. The sensor detects changes in magnetic flux.

A method is provided for measuring a thickness of a layer of rubber-like material. The layer of rubber-like material includes a free face in contact with air and a face joined to an adjacent reinforcement made of elements electrically insulated from one another. Each of the elements includes at least one hysteretic material having a magnetic permeability greater than the magnetic permeability of air. According to the method, a sensitive element, which emits an alternating magnetic field, is brought towards the layer of rubber-like material whose thickness is to be measured, hysteretic losses in the adjacent reinforcement are measured at terminals of the sensitive element, and a thickness of the layer of rubber-like material is evaluated based on the hysteretic losses.

A coin sensor comprising a first inductive branch with a first inductor in series with a first resistor; a second inductive branch with a second inductor in series with a second resistor, wherein the first and second inductors are arranged facing each other on both sides of a passage channel of coins to be discriminated; at least one capacitive branch with a condenser and a resistor in series; an excitation circuit with a generator and at least one pair of switches, configured to alternately feed the first inductive branch and the second inductive branch with a pattern signal with spectral energy in two or more frequencies, such that the branch of the inductor excited at any given time is arranged in a bridge configuration with at least one capacitive branch; at least one differential amplifier configured to alternately measure the voltage between the exit nodes of the excited bridge.

This invention relates to tire tread wear monitoring. A sacrificial magnet portion is arranged in a tread of the tire so that it undergoes wear along with the tread and generates a useful magnetic field signal indicative of remaining tread thickness. With a magnetic field sensor arranged on or in the tire, an overall magnetic field signal is measured, which includes the useful magnetic field signal, and a superimposed interfering magnetic field signal generated by magnetizable material contained in the tire. A non-sacrificial magnet portion is used to saturate the magnetizable material at least locally so as to make the interfering magnetic field signal sensed by the magnetic field sensor substantially independent of the useful magnetic field signal sensed by the magnetic field sensor. Further aspects of the invention relate to tires, e.g., vehicle tires, featuring a tire tread wear monitoring system.

Systems, methods, and apparatuses for inspecting a tank containing a flammable fluid are provided. A vehicle configured to inspect the tank can include a propeller, a battery, a control unit, an inspection device, and a ranging device. The battery provides power to the propeller, the control unit, the inspection device, and the ranging device. The control unit generates a map of the tank and determines a first position of the vehicle on the map. The propeller moves the vehicle through the flammable fluid in the tank. The inspection device includes a pulsed eddy current array to obtain inspection data indicating a quality of a tank wall. The control unit causes the propeller to move the vehicle from the first position to a second position within the tank. The control unit obtains first inspection data indicating the quality of the tank wall, and stores the first inspection data.