A plurality of captured images is acquired while changing a light illumination state. Each captured image is compared with a corresponding reference image to acquire a region where the captured image is darker than the reference image as a dark defect candidate region. From each of a plurality of captured images, a region where the captured image is lighter than the reference image is acquired as a lightness/darkness inverted region. Among the dark defect candidate regions, those that do not overlap by a prescribed criterion or more with any of the lightness/darkness inverted regions are excluded from defect candidates, and then the presence of a defect is acquired on the basis of the defect candidate regions. This suppresses over-detection of defects arising from, for example, grime on the surface during external appearance inspection.

A corrosion monitoring system includes one or more objects coupled to respective portions of a transformer tank. The one or more objects are configured to corrode before the respective portions of the transformer tank. At least one optical sensor is coupled to each of the objects. The at least one optical sensor has an optical output that changes in response to strain of the object. An analyzer is coupled to the at least one optical sensor. The analyzer is configured to perform one or more of detecting and predicting corrosion of the transformer tank based on the output of the at least one optical sensor.

A corrosion monitoring system includes one or more objects coupled to respective portions of a transformer tank. The one or more objects are configured to corrode before the respective portions of the transformer tank. At least one optical sensor is coupled to each of the objects. The at least one optical sensor has an optical output that changes in response to strain of the object. An analyzer is coupled to the at least one optical sensor. The analyzer is configured to perform one or more of detecting and predicting corrosion of the transformer tank based on the output of the at least one optical sensor.

An accelerated corrosion test apparatus includes: a moisture sensor disposed near the reinforcing steel exposed from a cracked portion of concrete; a weight measuring instrument that measures a weight of the reinforced concrete specimen; and a control terminal that is connected both to the moisture sensor and to the weight measuring instrument and controls a temperature and humidity control device, thereby alternately and repeatedly performing a wetting step of supplying moisture to the inside of a crack in the cracked concrete, and a drying step of removing moisture in the inside of the crack and moisture on the exposed surface of the reinforcing steel, wherein the control terminal terminates the wetting step and starts the drying step when moisture is detected in the moisture sensor, or when change in slope of weight change of the reinforced concrete specimen is detected, after the start of the wetting step.

An accelerated corrosion test apparatus includes: a moisture sensor disposed near the reinforcing steel exposed from a cracked portion of concrete; a weight measuring instrument that measures a weight of the reinforced concrete specimen; and a control terminal that is connected both to the moisture sensor and to the weight measuring instrument and controls a temperature and humidity control device, thereby alternately and repeatedly performing a wetting step of supplying moisture to the inside of a crack in the cracked concrete, and a drying step of removing moisture in the inside of the crack and moisture on the exposed surface of the reinforcing steel, wherein the control terminal terminates the wetting step and starts the drying step when moisture is detected in the moisture sensor, or when change in slope of weight change of the reinforced concrete specimen is detected, after the start of the wetting step.

The apparatus is useful for monitoring integrity of casings, tubings, and other tubular strings in oil and gas wells. An apparatus for defectoscopy of downhole casings includes several units in a housing. An electromagnetic field generation unit generates excitation pulse of a specified amplitude and duration. It includes an exciter coil containing a core made a high magnetic permeability material. A pick-up sensor unit includes an integral pick-up coil and radial pick-up coils mounted around the exciter coil winding. Each pick-up coil has a U-shaped core with poles directed perpendicularly to the surveyed pipe surface and having a center line parallel to the center line of the exciter coil winding. A data control, acquisition, and processing unit includes operational amplifiers with variable amplification factors and analog-to-digital converters (ADCs) that transmit signals from the pick-up coils to software for casing defect analysis.

The apparatus is useful for monitoring integrity of casings, tubings, and other tubular strings in oil and gas wells. An apparatus for defectoscopy of downhole casings includes several units in a housing. An electromagnetic field generation unit generates excitation pulse of a specified amplitude and duration. It includes an exciter coil containing a core made a high magnetic permeability material. A pick-up sensor unit includes an integral pick-up coil and radial pick-up coils mounted around the exciter coil winding. Each pick-up coil has a U-shaped core with poles directed perpendicularly to the surveyed pipe surface and having a center line parallel to the center line of the exciter coil winding. A data control, acquisition, and processing unit includes operational amplifiers with variable amplification factors and analog-to-digital converters (ADCs) that transmit signals from the pick-up coils to software for casing defect analysis.

Method for determining the geometry of multiple defects in a magnetizable object using a reference data record of the object, comprising determining an initial defect geometry as starting defect geometry, determining a first MFL prediction data record as starting prediction data record on the basis of the starting defect geometry, and iteratively matching the starting defect geometry to the geometry of the real defect(s) by means of the EDP unit and by means of multiple expert routines (11) running in competition and preferably in parallel with one another.

Method for determining the geometry of multiple defects in a magnetizable object using a reference data record of the object, comprising determining an initial defect geometry as starting defect geometry, determining a first MFL prediction data record as starting prediction data record on the basis of the starting defect geometry, and iteratively matching the starting defect geometry to the geometry of the real defect(s) by means of the EDP unit and by means of multiple expert routines (11) running in competition and preferably in parallel with one another.

Various methods and systems are provided for analyzing sample inclusions. As one example, a correction factor may be generated based on inclusion properties of a first sample determined using both an optical emission spectrometry (OES) system and a charged-particle microscopy with energy dispersive X-ray spectroscopy (CPM/EDX) system. The OES system may be calibrated with the correction factor. The inclusion properties of a second, different, sample may be determined using the calibrated OES system.