Remote field inspection

Remote field inspection (hydroscope) Most advanced technique currently available Detects areas of corrosion pitting, as well as through holes Can be used to give an estimate of the future life of a line More expensive than leak detection Requires access to the inside of the water line, which may require cleaning Knowledge of the relationship between pit size and residual life of the pipe is not yet complete Limited to pits of less than 3 cm in size. 

Remote field inspection Can detect single or multiple broken wires Inspection gives complete picture of damage to the pipeline Currently only available for use in embedded type pipelines Requires man entry into pipes... 

The development of Remote Field Eddy Current probes requires experience and expensive experiments. The numerical simulation of electromagnetic fields can be used not only for a better understanding of the Remote Field effect but also for the probe lay out. Geometrical parameters of the prohe can be derived from calculation results as well as inspection parameters. An important requirement for a realistic prediction of the probe performance is the consideration of material properties of the tube for which the probe is designed. The experimental determination of magnetization curves is necessary and can be satisfactory done with a simple experimental setup. 

Advances in Instrumentation for Remote Field Eddy Current Inspection. 

T R Schmidt. History of the Remote-Field Eddy Current Inspection Technique. Materials Evaluation Jan 1989... 

Remote Field Eddy Current Inspection, A selective NTIAC Bibliography. Southwest Research Institute, San Antonio, Texas. 

Remote field eddy permanent record Automated inspection Volumetric test percent wall loss... 

Acoustic leak detection methods such as illustrated in Fig. 8.4 may find already broken or damaged pipes [7]. However, corrosion monitoring possibly may identify areas where corrosion activity on pipes is likely while the remote field effect can inspect pipes to find damage before they fail. A complete diagnostic program is likely to use all these inspection methods. 

A large percentage of eddy-current inspections are conducted in the field, away from the home base and often in remote or inaccessible locations. Using local telephone lines or mobile phone lines would allow the inspector to beam his data back to the office. In this way highly qualified personnel can be consulted when problems or difficult to interpret results occur. Inspectors no longer need to feel isolated on site. 

As was discussed in the preceding sections, in many operating nuclear power plants the buildup of contamination results in radiation levels at the systems and components which lead to considerable radiation exposure of workers, in particular during the course of inspection and repair work. In order to meet this situation, permanent or temporary shieldings are frequently installed and, as far as necessary, remote-controlled and automatically operating equipment is employed to reduce, as far as possible, the stay time of people in the radiation field. Nevertheless, there are often operations to be carried out whose preparation and execution make the removal or at least a radical reduction in the radiation sources, i. e. a decontamination of the respective regions, necessary. 

Design structures, systems, and components to accommodate remote and semi-remote operation, maintenance, and inspection, thereby effectively reducing time spent in radiation fields. 

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