Bridge method for the accurate measurement of waveguide wall loss

1977 ◽  
Vol 124 (7) ◽  
pp. 589 ◽  
Author(s):  
R.V. Gelsthorpe ◽  
R.G. Bennett
Keyword(s):  
Waveguide Wall ◽  
Bridge Method ◽  
Wall Loss

A Bridge Method for Dielectric Measurements of Grain and Seed in the 50- to 250-MHz Range

1970 ◽  
Vol 13 (1) ◽  
pp. 0018-0020 ◽  
Author(s):  
J. L. Jorgensen ◽  
A. R. Edison ◽  
S. O. Nelson and L. E. Stetson
Keyword(s):  
Dielectric Measurements ◽  
Bridge Method

2. On the Measurement of Resistance to Electrolytes

1884 ◽  
Vol 12 ◽  
pp. 178-181
Author(s):  
Cargill G. Knott
Keyword(s):  
Rapid Growth ◽  
Electrical Resistance ◽  
Wheatstone Bridge ◽  
Bridge Method

The difficulties attending the measurement of the electrical resistance of electrolytes are well known, the rapid growth of the polarisation of the electrodes especially preventing the application of the ordinary Wheatstone Bridge method. The polarisation may be kept down by using alternating currents, as was done by Kohlrausch; and this method is no doubt the most general and most accurate which has yet been applied.

Guided Wave Testing: Maximizing Buried Pipe Corrosion Knowledge From Each Excavation

2012 ◽  
Author(s):  
Andy Crompton ◽  
Roger Royer ◽  
Mark Tallon ◽  
Stephen F. Biagiotti
Keyword(s):  
Guided Wave ◽  
Piping System ◽  
Case Histories ◽  
Direct Examination ◽  
Buried Pipe ◽  
Industry Standard ◽  
Limited Effectiveness ◽  
Wall Loss ◽  
Assurance Process ◽  
Non Destructive

Excavation and Direct Examination of buried piping using conventional non-destructive examination (NDE) has been the traditional inspection approach for decades and remains the only quantitative method for piping evaluations in plants when internal in-line inspection tools cannot be used due to geometry or other constraints. This “difficult to assess” piping presents many challenges, including limited effectiveness of traditional indirect inspection tools, high cost and operational concerns associated with excavations, and the ability to evaluate only a small sampling of a piping system. Many inspection technologies exist for buried pipe assessments; however, no indirect techniques provide the ability to yield quantitative wall loss values suitable for ASME fitness for service calculations beyond what’s exposed in the excavation. An evolving technology, guided wave testing (GWT), has many applications including the ability to provide assessment information beyond the excavation. In this paper, the application of GWT for buried piping inspection will be discussed. We will review: principles behind its operation; the competitive technologies on the market; challenges for the technology; management of data within the Electric Power Research Institute (EPRI) industry standard buried pipe database (BPWorks™ 2.0); trending; case histories showing how GWT can be used to extend the knowledge gained during an excavation by screening adjacent areas for more significant corrosion than observed in the excavated and exposed area; coupling GWT results with other inspection technologies to gain an enhanced interpretation of the overall condition of the line; and how to incorporate this data into an effective structural and/or leakage integrity program as part of the reasonable assurance process.

Nondestructive Evaluation for Duplex Stainless Steel Tube Using Multi-Frequencies Remote Field Testing

2015 ◽  
Vol 659 ◽  
pp. 633-637
Author(s):  
Cherdpong Jomdecha ◽  
Isaratat Phung-On ◽  
Kasemsak Sritarathorn
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Eddy Current ◽  
Field Testing ◽  
Steel Tube ◽  
Stainless Steel Tube ◽  
Frequency Range ◽  
Testing Frequency ◽  
Wall Loss ◽  
Different Depths

This paper presents the determination of Remote Field Testing (RFT) frequencies to accomplish the inspection of duplex stainless steel tubes grade ASME/ASTM SA 789. The tube specimen was 25.4 mm of outside diameter, and thickness of 1.65 mm with the different artificial flaws. A dual-pickup coils type of RFT probe was employed to inspect the specimen by inserting a probe within the tube. Optimum of testing frequency Range was determined based on an eddy current through transmission generation to produce different magnetic field density. RFT inspection frequency range for duplex stainless steel was consequently determined from 5 to 25 kHz which was different than those inspection frequencies of general ferromagnetic steel tube. In the experiment, calculated frequencies were then generated to the Eddy current (ET) and RFT probes for detecting the flaws of the tube specimen. The inspection signals were specifically shown in function of impedance plane to identify the flaw characters. The results showed that the RFT can be utilized to quantify the wall loss levels of duplex stainless-steel tube better than the ET. Especially, phase angle of inspection signals can be used to evaluate the different depths of the wall losses. Sensitivity of RFT showed the detection performance at minimum 20% of tube wall loss.

Diffusion and Wall Loss of Magnesium in Decaying Plasma

1999 ◽  
pp. 497-498
Author(s):  
I. Rusinov ◽  
A. Blagoev ◽  
M. Pentcheva ◽  
V. Yordanov
Keyword(s):  
Wall Loss

Infrared Dim Target Detection Based on Statistical Characteristics and Bridge Method

2019 ◽  
Vol 56 (6) ◽  
pp. 060401
Author(s):  
韩志华 Han Zhihua ◽  
刘晶红 Liu Jinghong ◽  
徐芳 Xu Fang
Keyword(s):  
Target Detection ◽  
Statistical Characteristics ◽  
Bridge Method
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