Recent advances in probe design for eddy current testing of heat exchangers

1989 ◽  
Vol 22 (4) ◽  
pp. 217-221 ◽  
Author(s):  
V.S. Cecco ◽  
F.L. Sharp
Keyword(s):  
Eddy Current ◽  
Heat Exchangers ◽  
Eddy Current Testing ◽  
Probe Design ◽  
Current Testing ◽  
Recent Advances

An Engineer’s Guide to Eddy Current Testing

2013 ◽  
Author(s):  
Robert J. Bell ◽  
Albert S. Birks
Keyword(s):  
Heat Exchanger ◽  
Eddy Current ◽  
Heat Exchangers ◽  
Signal Analysis ◽  
Test Methods ◽  
Eddy Current Testing ◽  
High Rate ◽  
Thin Wall ◽  
Electrical Currents ◽  
Current Testing

This paper applies to individuals charged with maintaining the reliability of shell and tube heat exchangers. These persons typically specify and/or retain the services of others to examine heat exchangers with nondestructive test methods, such as eddy current and are responsible for submitting run-repair-replace recommendations to management. Electromagnetic Testing (ET) uses the electromagnetic characteristics of components made of conductive materials to determine their condition. Eddy Current Testing (ECT), an electromagnetic method that utilizes induced electrical currents, is usually used to examine non-ferromagnetic materials. ECT’s high rate of examination, relatively good accuracy with thin wall components, repeatability and volumetric measurement make it an ideal method for examining nonmagnetic heat exchanger tubes. This paper will provide a brief description of the method, concentrating on ECT because most power generation industry heat exchanger tubing is non-ferromagnetic in nature. This paper will also address the following: • Training and Certification of Technicians. • ET signal analysis, an exacting science? • ASME Section V, Appendix II vs. Appendix VIII for in-situ ECT of all heat exchanger tubing. • Signal analysis variables and limitations. • A need to know the potential degradation mechanisms. • Condition assessment vs. eddy current testing.

scholarly journals An Eddy Current Testing Platform System for Pipe Defect Inspection Based on an Optimized Eddy Current Technique Probe Design

Sensors ◽  
2017 ◽  
Vol 17 (3) ◽  
pp. 579 ◽  
Author(s):  
Damhuji Rifai ◽  
Ahmed Abdalla ◽  
Ramdan Razali ◽  
Kharudin Ali ◽  
Moneer Faraj
Keyword(s):  
Eddy Current ◽  
Eddy Current Testing ◽  
Probe Design ◽  
Defect Inspection ◽  
Testing Platform ◽  
Current Testing ◽  
Current Technique ◽  
Platform System

scholarly journals Analysis of Lift-Off Effect on Transmitter-Receiver Probe in Eddy Current Testing

2020 ◽  
Author(s):  
Qing Zhang ◽  
Xin Li ◽  
Guiyun Tian
Keyword(s):  
Analytical Model ◽  
Eddy Current ◽  
Signal To Noise Ratio ◽  
Ferromagnetic Materials ◽  
Eddy Current Testing ◽  
Probe Design ◽  
Deep Penetration ◽  
Current Testing ◽  
Straight Line ◽  
Lift Off

The Transmitter-Receiver Probe (TR probe), which has improved signal-to-noise ratio, deep penetration depth, and directional measurement is used in pulsed eddy current testing (PECT). Whereas, the lift-off effect on the TR probe is one of the main obstacles. The purpose of this paper is to analyze the lift-off effects on the TR probe and presents a feature for lift-off estimation. Firstly, an analytical model of a TR probe is given based on previous studies. Secondly, on the basics of the analytical model, the spectrum of the PECT signal is studied, and the lift-off effects on the TR probe are analyzed. Then, the lift-off effects under different coil distances are studied and a D Intersect Point (DIP) is proposed for the lift-off estimation. Results show that the TR probe can be used to reduce the lift-off effect for the non-ferromagnetic materials and the ferromagnetic materials. And both the DIP time and amplitude can be used for lift-off estimation. However, the DIP time is better, as its evolution curve with lift-off is a straight line with the same slope. The study is believed to be helpful for the TR probe design, the lift-off measurement, and the thickness assessment and defect quantification.

Probabilistic evaluation of detection capability of eddy current testing to inspect pitting on a stainless steel clad using multiple signal features

2020 ◽  
Vol 64 (1-4) ◽  
pp. 47-55
Author(s):  
Takuma Tomizawa ◽  
Haicheng Song ◽  
Noritaka Yusa
Keyword(s):  
Stainless Steel ◽  
Eddy Current ◽  
Pressure Vessels ◽  
Eddy Current Testing ◽  
Probability Of Detection ◽  
Current Testing ◽  
Multiple Signal ◽  
Signal Features ◽  
Inner Surface ◽  
Drill Holes

This study proposes a probability of detection (POD) model to quantitatively evaluate the capability of eddy current testing to detect flaws on the inner surface of pressure vessels cladded by stainless steel and in the presence of high noise level. Welded plate samples with drill holes were prepared to simulate corrosion that typically appears on the inner surface of large-scale pressure vessels. The signals generated by the drill holes and the noise caused by the weld were examined using eddy current testing. A hit/miss-based POD model with multiple flaw parameters and multiple signal features was proposed to analyze the measured signals. It is shown that the proposed model is able to more reasonably characterize the detectability of eddy current signals compared to conventional models that consider a single signal feature.

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