An apparatus for determining the thickness of media is provided and includes a ferrous plate, a solenoid mounted perpendicular to the ferrous plate, and a magnet at the end of the solenoid piston. The solenoid piston ranges from a retract position to a down position where the magnet presses on media fed in the gap between the solenoid piston and the ferrous plate. A current source connected to the solenoid moves the piston to the retract position when the current source is energized. A detector is provided to determine when the solenoid piston is in the retract position. A programmable device controls the current source and a time measurement device. The programmable device simultaneously starts the time measurement device and increases current to the solenoid, thereby retracting the piston and timing the retraction.

A process for continuous manufacturing of steel strips for packaging coated with a passivation layer is provided. The layer is an aqueous passivation solution, the thickness of which is less than 3 ?m and the viscosity of which is less than 1.5.Math.10.sup.?3 Pa.Math.s at 20? C., and is deposited on one of the faces of the strip. This depositing is carried out by a transfer roller in contact with the strip and with a second coating roller, the surface of which has a plurality of hexagonally shaped cells, the line count of which is between 50 and 200 lines per centimeter, and the total volume of which is between 5.Math.10.sup.?6 and 10.Math.10.sup.?6 m.sup.3 per square meter of roller surface. The coating roller is fed with aqueous passivation solution by dipping in a tank equipped with wiping means and the strip runs at a speed greater than or equal to 400 m/m. An apparatus for implementation of the process is also provided.

Systems, apparatuses, and methods for measuring material thickness of multiple tubulars by placing a logging tool in a well with multiple conductive tubulars and generating an electromagnetic field that interacts with the tubulars. A logging tool obtains the measurements using one or more receivers. A monitoring system or the logging tool applies the measurements to a mathematical model that considers at least a transition zone and one or both of a near field zone and a remote field zone of the electromagnetic field that interacts with the multiple conductive tubulars. Furthermore, the monitoring system or the logging tool may ascertain a thickness of the one or more conductive tubulars using the mathematical model.

The invention relates to a method for measuring the thickness of non-magnetisable layers (51) on a magnetisable base material (52), the permeability of which is not known, having a measuring probe (11), which has a probe head (17), which comprises a pot core (31) having a first and second coil (36, 37), which lie on a common geometric axis (16), and in which the first and second coils (36, 37) form a first coil pair (38), and which has a bearing calotte (21) in a common axis (16), in which the probe head (17) is placed on the layer (51) to measure the thickness of the layer (51) on the base material (52), wherein a first interaction volume is detected by the first coil pair (38) with a field focusing caused by the pot core (31), a second interaction volume is detected by a second coil par (44) with a first and second coil (42, 43), which is arranged outside the pot core (31) and jointly with the geometric axis (16) without field focusing by the pot core (21), and the detected first and second base material volume is processed in an evaluation device (13) and compared to each other for compensating a permeability of the base material (52), on which the layer (51) to be measured is applied, and a layer thickness is output for the measured layer (51), which is corrected by the influence of the permeability of the base material (52).

Embodiments relate to a system and method for detecting and remediating selective seam weld corrosion in conduits such as steel pipes that transport oil and gas products. In particular, a probe detects magnetic flux leakage in at least two orientations. Anomalies in the conduit are then identified and assessed for selective seam weld corrosion based on factors that include the magnetic flux leakage detection and the depth of the anomalies. For certain categories of assessed anomalies, the corresponding portions of the conduit are selectively remediated in accordance with these factors.

In some implementations, a controller may receive, from a sensor system of the machine, sensor data indicating a movement of an idler block of an idler assembly of an undercarriage of the machine. The controller may determine, based on the sensor data, that the idler block has moved from a first position to a second position. The controller may determine an amount of wear of an idler of the idler assembly based on the idler block moving from the first position to the second position. The controller may determine whether the amount of wear satisfies a wear threshold. The controller may cause the machine to perform an action based on determining whether the amount of wear satisfies the wear threshold.

Embodiments included herein are directed towards a system and method for analyzing an oilfield casing using an apparent thickness approach. Embodiments may include providing an induction instrument having at least one of a transmitter and a receiver configured to operate at one or more frequencies. Embodiments may further include generating, using data acquired by the induction instrument, one or more apparent thickness transforms for at least one of a measured attenuation and a phase response associated with an oilfield casing, wherein generating includes assuming a proportionate increase in all casing thicknesses.

Aspects of the subject technology relate to systems, methods, and computer-readable media for accounting for artifacts in pipe measurements made by an electromagnetic pipe inspection tool. Measurements gathered in a plurality of pipes across different depth points are accessed. Initial estimates of an attribute associated with the plurality of pipes are made for each pipe and a total estimate of the attribute for the plurality of pipes as a whole are made across the different depth points. Corresponding initial estimates of the attribute for each pipe are filtered to remove an artifact present in at least one of the corresponding initial estimates while the total estimate is preserved. Corresponding final estimates of the attribute for each pipe are determined based on both the measurements and corresponding filtered initial estimates of the attribute for each pipe. Integrity of each pipe can be determined based on the corresponding final estimates of the attribute.

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.

Various downhole logging tools and methods of using and making the same are disclosed. In one aspect, a downhole logging tool for inspecting one or more well tubulars includes a housing adapted to be supported in the one or more well tubulars by a support cable. A first transmitter, a second transmitter and a third transmitter are positioned in longitudinally spaced-apart relation in the housing and are operable to generate magnetic fields. Driving circuitry is operatively coupled to the first transmitter, the second transmitter and the third transmitter to selectively fire the first transmitter, the second transmitter and the third transmitter in multiple transmission modes to generate magnetic fields to stimulate pulsed eddy currents in the one or more well tubulars. A first receiver is positioned in the housing to sense decaying magnetic fields created by the pulsed eddy currents. Electronic circuitry is operatively coupled to the first receiver to determine a parameter of interest of the one or more well tubular from the sensed decaying magnetic fields.