Numerical Study on the Phase Sensitivity Variation in Low Frequency Primary Microphone Calibrations

Round 1

Reviewer 1 Report

This is an interesting simulation study about the phase calibration of infrasound microphones in the very low frequency range using the laser - pistonphone method. The most relevant discovery is the effect of the vent depending on its location outside or inside the calibrating field. Other factors are also considered.

There are a few minor errors in the text:

Line 134: The vector symbol over "n" is wrong.

Line 215: Should say "more severe".

My main concern about this work is the lack of experimental measurements which could confirm the findings of the simulations. I need a rationale concerning the exclusive use of simulation, so that, if the authors are unable to conduct the experiments by themselves, at least, they provide an experimental confirmation protocol. After the experimental part, of lack of it, is justified, I'll see better the motivation and reach of this research.

Author Response

Please see the attachment.

Author Response File: Author Response.doc

Reviewer 2 Report

Comments

Abstract

Line 12: “But” à “However,” will be better for reading.

Line 13: “That” seems to be missing after “speculate”.

Introduction

Line 39: “More over” à “Moreover”

Line 41: Keep consistency between “infrasonic” and “infrasound”, if there is no significant difference.

Line 50: What is the definition of “secondary calibration”? The definition appears later part but is used earlier, which makes it ambiguous.

Line 55: “due to” à “since” or “because”

Line 58: What is the National Metrology Institutes? Is it a certain institute? Then, note where it is.

Line 62: “And ~” writing on the primary and secondary calibration is out of flow since these are mentions earlier.

Line 91: “take advantage” à “by taking advantage”

Section 2

Line 103: “The cavity wall”: What material is used for the wall? Is it modeled as flexible structure? If it is just a rigid wall option in the FE model, then mentioning of its thickness is meaningless.

Line 107: “Tab. 1” à “Table 1”: It is unusual for me to abbreviate the “Table”.

Line 111: adding “and” after “except the constant amplitude,” will be better to read.

Line 113: “affecting” à “affect”

Line 134: What is the meaning of  1 over n which is the normal vector? It is usual to use bold for vectors like “n”.  

Line 147: For the subsection, it is better to use numbering like “2.2.1 results in frequency domain”. Likewise, Line 162, 213, and 227.

Line 180: “Let’s” à “Let us” will be more formal.

Line 185: “So that” à “therefore” or “thus” will be better.

Section 3

Line 191: “excite” à “excites”

Line 202: “Tab. 2” à “Table 2”

Line 209: “as” à “to”

Line 233: “The greater ~”: It is not a sentence. Make it a full sentence like “The greater the pressure attenuation leads to ~”.

Section 4

Line 247: “huge” à “computationally expensive” will be better to understand.

“unreliable” is a dangerous expression because the FE solutions usually converge to the accurate result when the mesh is dense enough.

Line 260-265: Explaining the FE model with just writing is hard to understand. Explaining it with pictures of the model will be better to follow.

Line 271: Move “not only” after has.

Line 272: It is hard to understand why “However” is used to connect the sentences.

Line 280: “take” à “taking” and “fourier” à “Fourier”

Line 289: deleting “then” will be better.

Line 301-303: This sentence is hard to follow. “faces” à “face”

Line 323: “the the diaphragm” à “the diaphragm”

Line 325-327: I think this is not a full sentence or at least hard to read. Revising this sentence will be better to understand.

“affect” à “affect”

“much less”: what is the reference? less than what?

Line 593-598: This summary is redundant.

Conclusion

There are too many paragraphs. It is hard to follow and seems to out of core argument. It is better to reduce the paragraphs to one or two.

Line 330-335: This part is repeated part appearing in introduction and abstract. I think it is not redundant to write the same contents again.

Line 343: “in the calibrating sound field or out”: It is hard to understand. What “out” means?

Line 348: “affect” à “affects”

Line 352-353: “Different from ~ obtained.”: It is not a sentence. Make it a sentence.

Line 353-355: “The primary ~ system.”: This sentence is hard to understand. Revision is required.

Author Response

Please see the attachment.

Author Response File: Author Response.doc

Round 2

Reviewer 1 Report

I appreciate the authors' effort to improve their work and I'm very satisfied with the response to my comments in a separate document. However, I don't understand why some of the information of this valuable response letter has not been included in the paper. I recommend to include part of the justification of the lack of experimental results and the relevant previous bibliography in this regard in the paper.

Author Response

Please see the attachment.

Author Response File: Author Response.doc

Reviewer 2 Report

Author Response

We would like to express our sincere thanks to dear reviewer #2.

Round 3

Reviewer 1 Report

I appreciate the authors' effort to include the suggested changes. Now the paper is clearer and the scope of the full research is grasped. Finally, I recommend some English improvement, especially in the recently added parts, because some phrases are somewhat poorly written, perhaps due to time constraints in sending the revised version.

Author Response

Responds to the comments of reviewer #1

We would like to express our sincere thanks to dear reviewer #1 for your constructive and positive comments. The comments and responds are as following:

• Comment 1: I appreciate the authors' effort to include the suggested changes. Now the paper is clearer and the scope of the full research is grasped. Finally, I recommend some English improvement, especially in the recently added parts, because some phrases are somewhat poorly written, perhaps due to time constraints in sending the revised version.
• Response 1: This comment is highly appreciated. The revised content is given as follows:

1. Line 15, “will” was added.
2. Line 27, “the” was added.
3. Line 49, “the” was deleted.
4. Line 56, “The above infrasound calibration studies mainly focus on getting the phase consistency of infrasound sensors based on the comparative (secondary) calibrations, but the primary calibration technique is few studied.” was added.
5. Line 60, “using multiple planewave couplers” was revised as “based on the reciprocity method”
6. Line 71, “acting on microphone diaphragm” was deleted.
7. Line 85, “the wave motion correction,” was deleted.
8. Line 86, “(wave motion correction)” was added.
9. Line 86, “is” was revised as “can be”
10. Line 100, “the” was added.
11. Line 100, “phenomena” was added.
12. Line 103, “not” was revised as “outside atmosphere”
13. Line 167, “pressure” was added.
14. Line 167, “While in actual cases,” was deleted.
15. Line 167, “the” was revised as “The”
16. Line 168, “the” was added.
17. Line 169, “and works” was added.
18. Line 169, “the” was added.
19. Line 211, “section IV” was revised as “Section 4”
20. Line 250, “the” was added.
21. Line 252, “the” was added.
22. Line 264, “the” was added.
23. Line 274, “microphone” was revised as “the”
24. Line 275, “inserted” was deleted.
25. Line 275, “outside” was added.
26. Line 290, “the” was added.
27. Line 306, “the” was added.
28. Line 319, “resistance” was added.
29. Line 351, “studied” was revised as “studies in this paper”
30. Line 353, “study” was revised as “studies”
31. Line 354, “sensors” was deleted.
32. Line 354, “microbarometers” was added.
33. Line 355, “as” was revised as “The amplitude and phase responses of MB2005 microbarometer are”
34. Line 355, “[15]” was revised as “, and the MB3 microbarometer shows the same tendency [15].”
35. Line 357, “sensors” was revised as “both microbarometers”
36. Line 358, “we obtained” was revised as “as shown in Figure 17.”
37. Line 360, “microbarometer is” was revised as “microbarometers are”
38. Line 360, “the” was added.
39. Line 361, “calibration is” was revised as “calibrations are”
40. Line 365, “For the verification on” was revised as “To verify”
41. Line 365, “the” was added.
42. Line 366, “its” was revised as “the”
43. Line 367, “should” was revised as “will”
44. Line 367, “bought” was revised as “selected as the research object”
45. Line 368, “that” was revised as “, which”
46. Line 368, “should be manufactured” was added.
47. Line 369, “, should be manufactured” was deleted.
48. Line 371, “displacement waveform” was revised as “vibration displacement”
49. Line 372, “in this paper” was deleted.
50. Line 373, “This is” was revised as “The above experimental study will be”

Again, we would like to express our sincere thanks to dear reviewer #1 for your constructive and positive comments, which helped us a lot in improving the quality of our paper and also our knowledge. If there are any problems that are not completely solved, please do not hesitated to tell us.

Author Response File: Author Response.doc