Non-Destructive Subsurface Inspection of Marine and Protective Coatings Using Near- and Mid-Infrared Optical Coherence Tomography
, Christos Markos 1,2, Niels M. Israelsen 1,2, Peter J. Rodrigo 4, Getinet Woyessa 1, Peter Tidemand-Lichtenberg 4, Christian Pedersen 4, Claus E. Weinell 3, Søren Kiil 3 and Ole Bang 1,2,5Round 1
Reviewer 1 Report
Dear Authors,
I have read your paper "Non-Destructive Sub-Surface Inspection of Marine and Protective Coatings using Near- and Mid-Infrared Optical Coherence Tomography" carefully.
This paper describes the NDT complex method of the examination of the coatings.
The paper is easy to read.
Methods are properly described, so that other research groups may reproduce them.
The paper is interesting. However, it requires few corrections.
- Please, add a section of the abbrivations. I leave my suggestion to the authors for reflection.
The paper can be accepted for publication after minor improvements.
Author Response
Dear Reviewer 1,
Please see our response in the attached PDF.
On behalf of all authors, With kind regards,
Christian Rosenberg Petersen
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper topic is interesting and paper can be published but only after the above suggestions:
Abstract: The abstract is expected to include a brief digest of the research, that is, new methods, results, concepts, and conclusions only. The abstract needs to be more focused and achievements needs mentioned clearly. At the moment abstract is more like an introduction than abstract. Please add some information from the conclusion (quantifications).
Introduction: I personally feel that this part of paper is not concise enough from a reader’s perspective. At the moment is quite far from journal scope. In introduction is lots of errors: Error! Reference source not 134 found. I do not understand why nobody check it from Authors and Editors. Introduction must provide a comprehensive critical review of recent developments in a specific area or theme that is within the scope of the journal (coatings and manufacturing aspects), not only a list of published studies or a bibliometric one. Introduction is expected to have an extensive literature review followed by an in-depth and critical analysis of the state of the art. References section should be extensive about information connecting with non-destructive inspections. I suggest add information to better describe what other researchers have done in this area. I suggest add important articles from this field (optical non-destructive inspection), for example:
TOPOGRAPHIC INSPECTION AS A METHOD OF WELD JOINT DIAGNOSTIC. TEHNICKI VJESNIK-TECHNICAL GAZETTE Volume: 23 Issue: 1 Pages: 301-306 Published: FEB 2016
Influence of argon pollution on the weld surface morphology. MEASUREMENT Volume: 70 Pages: 203-213 Published: JUN 2015
Generally at the moment is very hard to look on this paper due errors and format problem. Each one of the cited references within the body of the paper should be discussed individually and explicitly to demonstrate their significance to the study. Also note that cited authors' surname should be used as the subject of a verb, and then state in one or two sentences what they claim, what evidence they provide to support their claim, and how the work is evaluated. Additionally, Authors do not write their paper in the context of Instrumentation and Measurement. Authors should present their work properly within the existing metrology literature; i.e., papers published in the metrology and measurement journals, and compare their work with these latest related measurement work. This comparison should be done analytically (in the introduction or related work section), experimentally (in the performance evaluation section), or both.
The strengths and limitations of the applied approach should be clearly identified for the readers of the paper.
The discussion is shallow and needs more details, the observations and future trends. This chapter should be connected with others published papers.
Some of the bullet points on the conclusion are simplistic; Please try to emphasize your novelty, put some quantifications, and comment on the limitations. This is a very common way to write conclusions for a learned academic journal. The conclusions should highlight the novelty and advance in understanding presented in the work.
Author Response
Dear Reviewer 2,
Please see our response in the attached PDF.
On behalf of all authors, with kind regards,
Christian Rosenberg Petersen
Author Response File: Author Response.pdf
Reviewer 3 Report
The manuscript deals with the application of the optical coherence tomography (OCT) for inspection of coatings integrity and detection of sub-surface defects in marine structures. The authors performed a short state-of-the-art in the first section, justifying the undertaken research with OCT and defining their superiority in the investigated problem. In the next section, the authors described the prepared specimens to simulate real marine conditions and the testing methodology using NIR and MIR OCT systems. In section 3, the authors presented the obtained results from OCT testing and deeply discussed the performance of the presented approach in identification of various types of defects and damage. The authors compared results obtained with NIR and MIR OCT systems, indicating characteristic artifacts and performance of both measurement approaches. The testing was performed also on different materials for evaluation the performance of the methodology with respect to surface parameters of the tested structures. The advantages of OCT in inspection of coatings is well highlighted and experimentally verified. The submitted manuscript is of high originality and practical meaning, however, some minor revisions are necessary before a publication.
1) It is recommended to enrich the statements in the first part of the first paragraph of the introduction with appropriate references.
2) It is likely to discuss other studies related to structural coatings, since the most of the discussed previous works are related with inspection of paintings.
3) Please carefully check the references to figures, there are errors starting from page 3.
4) It is recommended to add some basic information at the beginning of section 3 on interpretation of the resulting colormaps or at least provide some references to sources, where the interpretation is well explained, since OCT is the quite new method and numerous researchers may not be familiar with it.
5) Please check the indices in chemical formulas, i.e. in Cu2O, “2” should be the lower index.
6) Please correct the numbering of subsections.
Author Response
Dear Reviewer 3,
Please see our response in the attached PDF.
On behalf of all authors, with kind regards,
Christian Rosenberg Petersen
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Authors made changes in manuscript but only in Introduction part, discusion and conclusions are still not clearly presented.
Author Response
Dear Reviewer 2,
Please find attached response letter detailing our revisions of the manuscript.
On behalf of all authors, With kind regards,
Christian Rosenberg Petersen
Author Response File: 
Author Response.docx
