Electromagnetic Testing of Moisture Separation Reheater Tube based on Multivariate Singular Spectral Analysis
Round 1
Reviewer 1 Report
In the study, the signal for Moisture Separation Reheater Tube measured with Electromagnetic Testing are applied to Multivariate Singular Spectral Analysis. The study is well organized so that the comparison with analysis method of wavelet and Gabor filter and SSA and the measurement method of MFLT, ECT and PSECT are included. My comments are as follows,
In line 5, delete “and”
In line 196, E is italic and bold. The variable must be italic, and matrix should be bold through the manuscript. Please check through manuscript.
In line 211, please correct [xxx]
In experiment, please describe the number of turns of the coil ?
Please provide the development view of the tube including flaws so that reader easily understand your measurement results.
Author Response
Response to Reviewer 1 Comments
(the responses are highlighted by red color)
In the study, the signal for Moisture Separation Reheater Tube measured with Electromagnetic Testing are applied to Multivariate Singular Spectral Analysis. The study is well organized so that the comparison with analysis method of wavelet and Gabor filter and SSA and the measurement method of MFLT, ECT and PSECT are included. My comments are as follows,
Thank you for your comments! We revised the manuscript according to your comments and highlighted the changes in the revision. Thank you very much!
In line 5, delete “and”
There was a mistake of the word “and”. We revised it. Thank you!
In line 196, E is italic and bold. The variable must be italic, and matrix should be bold through the manuscript. Please check through manuscript.
Thank you! We revised the format through the manuscript.
In line 211, please correct [xxx]
This is a mistake. We corrected the reference [17]. Thank you!
In experiment, please describe the number of turns of the coil?
We provided the information of the coil in the revised version: “The bobbin coil has 130 turns in 10 mm length and using 0.2 mm diameter copper wire.”
Please provide the development view of the tube including flaws so that reader easily understand your measurement results.
Yes, we inserted a sample picture of the MSR tube with corrosion in Fig. 3 and the sketch drawing of the corrosion size with the position in Fig. 4. Thank you!
Author Response File: 
Author Response.pdf
Reviewer 2 Report
General Comments
The authors present various methods to monitor corrosion in moisture separator reheater tubes found in steam turbines. Three techniques are analyzed: magnetic flux leakage testing, eddy current testing, and partial saturation eddy current testing. The main goal of this manuscript is to look at different signal processing algorithms to analyze the data. My interests are more in electromagnetism than signal processing, so I am not sure I was the best reviewer for data analysis part of this paper.
The paper has several strengths and weaknesses. Strengths: The nondestructive testing methods are appropriate, well designed, and effective. The signal processing algorithms appear to work effectively, helping to analyze the data. The results suggest a good ability to detect corrosion in the tube. Weaknesses: The English is poor. Sometimes this is merely annoying, and sometimes I have difficulty understanding what the authors mean. Also, parts of the manuscript are confusing, quite apart from language problems. Figure 1 seems to get the physics wrong, unless I am confused about what is going on.
Below, I provide some specific comments about problems in the manuscript. After that, I provide a first pass at improving the English. I haven’t the time to go through the entire paper in detail, but I will make some suggestions, if for no other reason than to let the editor realize what I mean when I say the English is poor. I will start in the Introduction (Line 30) and make corrections through Line 50. I probably could have picked any 20 lines and found a similar number of English problems.
Specific Comments
Line 5: It looks as if the last author’s name is missing
Line 57: “affection”? Is this the correct word? Not sure what you mean.
Line 73-74: “There is some amount of 15 Hall InSb sensor elements”. Fig. 1 shows at least twice as many sensors.
Lines 83-90: I would think that the real value for using multiple sensors is that it provides information about changes with angle theta, whereas the fins are nearly independent of theta and change mainly along the length of the tube. You would not expect corrosion to occur in a loop independent of theta, so this would be a good way to differentiate corrosion from fins. Is that correct?
Fig. 1b: I am confused by this figure. Shouldn’t the bobbin coil create a 2nd magnetic field (red arrows) that is up on one side of the coil and down on the other? Therefore, shouldn’t the eddy currents be going clockwise round the tube on one side of the bobbin coil, and counterclockwise on the other side? Same issue in Fig. 1c. Also, the text (and common sense) says that the eddy current is largest at the inner surface, and is smaller at the outer surface. However, in Figs. 1b and 1c, it looks to me like the eddy currents arrows (yellow) are drawn larger at the outer surface than the inner surface. This might be an optical illusion (often it is difficult to tell if the different yellow arrows are meant to show different locations along the tube or across the tube wall).
Equation 5: In Eq. 5, is the “Z” subscript supposed to be an “H” subscript? If not, what is V_Z?
Equation 6: What is x? In Fig. 1 we were using a cylindrical coordinate system (r, theta, z) and now x appears. It could correspond to the different sensors (so, theta) or to different locations along the tube (so, z). Perhaps it is something else. I am confused. The variables “x” and “tau” better not have units, otherwise the exponential of the Gaussian has units, which it can’t.
Equation 7: Is one of the “L” subscripts supposed to be “H”? I suspect “omega<−omega_?” should be “omega<−omega_H”.
Line 211: “in Eq. (16) [xxx];” It looks like you forgot to add the reference number you are citing.
Comments about the English (starting with the Introduction, Line 30)
Line 33: “have fins in the outer surface” would sound better as “have fins on the outer surface”
Line 34: “in about three times” should be “by about three times”
Line 34: “thus improve the efficiency” should be “thus improving the efficiency”
Line 35: “moisture containing in the steam” should be “moisture contained in the steam”
Line 36: “is not only improving… but also helps to prevent” should be “is not only improving… but also helping to prevent”
Lines 37-38: “that could appear corrosion” should be “where corrosion could appear”
Lines 39-40: The way the text is written, it isn’t clear if “to prevent the failure of the MSR tubes and stop the operation of the nuclear power plant” means you do or don’t want to stop the power plant (“stop” or “prevent the stop”). I assume you don’t want to shut the power plant down, but it is always bad when I have to assume I know what you mean.
Line 43: “between … with…” should be “between … and…”
Line 45: “remaining coupling material” would sound better as “coupling material remaining”
Lines 49-50: “alternated material for 90-10 CuNi material” would sound better as “alternative for 90-10 CuNi material”
Author Response
Thank you for your comments!
We would like to respond to the file.
Please see the attachment.
Thank you!
Author Response File: Author Response.pdf
