Digitally Based Precision Time-Domain Spectrometer for NMR Relaxation and NMR Cryoporometry
Round 1
Reviewer 1 Report (Previous Reviewer 2)
The revised manuscript has been improved in consideration of the comments. I recommend the revised manuscript for publication.
Author Response
Changes : micro-2251960
Reviewer 1 does not appear to have requested changes, but a few lines were update in :
8.1. Peltier Cooled Variable-Temperature NMR Probe.
This paper has been brought fully up to date with a brief addition for a new CryoP6 NMR probe :
In CryoP5 and CryoP6 Peltier probes an additional higher power Peltier 496
element has been used between the dual-layer Peltier element and the water cooled block. 497
Using just Peltier cooling, in the CryoP4 temperatures at the copper plate down to -55 498
C have been achieved, and at the NMR sample down to -45 C , where there is a sample 499
thermocouple in direct contact with the glass NMR sample tube [28]. In the CryoP6 probe, 500
sample temperatures below -60 C are reached reliably.
Reviewer 2 Report (New Reviewer)
Reviewer responce of manuscript J. BeauW. Webber and Pavel Demin Precision digitally based Time-Domain Spectrometer for NMR Relaxation and NMR Cryoporometry.
NMR relaxation is widely used like the method of pore systems, viscous control etc. Till now a lot of different types of relaxometers are known starting from Bruker company "minispe" and other spectrometers over the word. Anyway from my point of view each new development should be published. Therefore this manuscript may be recommended for publishing.
It is necessary to show the new original points of proposal spectrometer compare to previous ones. This kind of analysis should be done.
Author Response
Reply to Referee 2 : micro-2251960
Comments and Suggestions for Authors
Reviewer responce of manuscript J. BeauW. Webber and Pavel Demin Precision digitally based Time-Domain Spectrometer for NMR Relaxation and NMR Cryoporometry.
“NMR relaxation is widely used like the method of pore systems, viscous control etc. Till now a lot of different types of relaxometers are known starting from Bruker company "minispe" and other spectrometers over the word. Anyway from my point of view each new development should be published. Therefore this manuscript may be recommended for publishing.”
“It is necessary to show the new original points of proposal spectrometer compare to previous ones. This kind of analysis should be done.”
A new sub-section has been added, to answer the request for comparing this NMR Spectrometer and NMR Cryoporometer with other instruments :
11.1. System Comparisons 666
There are two important comparisons needed here : 667
1) Comparison of NMR time-domain relaxation spectrometers, of which there are nu- 668
merous examples. For a point-by-point comparison of 12 such instruments, including 669
this Lab-Tools Mk3 instrument, please see reference [57], Figures 5 and 6. 670
2) Comparison of NMR Cryoporometers. We know of no other commercial NMR 671
Cryoporometers with which to make comparisons. Many commercial NMR Spectrometers 672
may be used to make variable temperature measurements, but in most cases the tempera- 673
ture control accuracy is a factor of 10 or so worse than this dedicated NMR Cryoporometer, 674
which limits the upper pore size that may be measured by a corresponding factor of 10. 675
Biography file Webber_JBW_2020 updated to Webber_JBW_2023
References :
- Webber., J.B.W. A review of the use of simple time-domain NMR/MRI for material-science. SN Appl. Sci 2021, 3, 809. 797
https://doi.org/10.1007/s42452-021-04791-2.
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
The authors show an original instrument able to perform cryoporometry. It is designed and built with the latest technologies both for pulse generation and data acquisition. This tool has also an original way of cooling the sample with a Peltier device embedded into the spectrometer. The paper describes in some details the capability of the instrument and in particular the programming aspects.
I have a high consideration for this great work but in the present form, I am not sure that it is suitable for a journal like Micro and mesoporous material. A journal like “Review of scientific instruments” might be more suitable, still with a high visibility; the paper is indeed focused on programming aspect that might useful for somebody building an instrument. Some parts of the paper are close to a user manual.
Moreover, the description of such an instrument should include:
1) A description of the NMR instrument with the following items (not really clear in the present version):
- Field homogeneity
- Pulse duration et pulse dead time
- Sensitivity, signal to noise ratio, limit of detection expressed in usual units
- Sample size
2) The control of temperature using the Peltier device (not really explained in the present paper):
- Temperature homogeneity (not an easy question)
- temperature accuracy and precision
- please demonstrate that you can reach a pore size of 1 micron (with water as the saturating liquid); this means that you can control the temperature within 0.1°C in the entire sample and at a very slow rate
- please show how the probe response is insensitive to temperature in the claimed temperature range
- how do you calibrate the sample temperature since the temperature probes are not located directly on the sample
The few examples given are very interesting, in particular the measurements of FID decays of brittle ice at different temperature. In this example, I can guess a probe and filter dead time of about 10 microsecond. Also a paper focusing on the comparison of N2 adsorption and cryoporometry techniqus would be of great interest for reader of MICMAT.
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
This article described the use, capabilities and application of a newly developed compact NMR time-domain relaxation spectrometer suitable for studying both solid and liquid samples. Use of the controlling GUI was described, and results from example NMR Relaxation and NMR Cryoporometric measurements were presented. The present manuscript should be considered for revision, referring to the following comments:
Comments:
1) The 1st keyword is “time-domain”. Some explanation for an NMR “time-domain” spectrometer should be described. How is the difference between the conventional NMR spectrometer and the “time-domain” NMR spectrometer?
2) In Fig. 1, the label of the horizontal axis is not clear.
3) Regarding Figs. 2-4, which is the NMR probe, and where is an NMR tube inserted?
4) How is the difference between the proposed NMR instrument and the conventional compact NMR spectrometer?
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The authors answered some of my comments correctly. And added a paragraph to summarize the specifications. However, I am still not convinced that the paper should be published in the present form. I truly believe that the scientific communitiy should be informed about such a great instrument.
Let me summarize my opinion: the paper has 41 figures, a large number. what do we learn from some of them ? for example that fitting can be done (figure 21) with different models (figure 22), or that we can choose different output format (figure 19). Is this worth publishing ? To my opinion, a FPGA based spectrometer is also not really new but certainly not so easy to build; as a result, the spectrometer is very small, and nice.
Moreover, concerning the main innovation which is the Peltier system, it is not really explained how it is build and why it improves considerably the temperature control and the range of pore size. The authors claim that they have a 10 mK accuracy (or better). This is really hard to believe because a reference bath is necessary when using thermocouples The authors indicate that they use a TRCRIII reference chamber, but this chamber has an accuracy of plus or minus 100mK (see documentation on internet). So yes the sensitivity of 1 mK is true, but the accuracy has to be further demonstrated.
I still recommend to the authors to write a condensed and punchy version of this document, concentrating on the main qualities of this instrument and not on side aspects of little interest.
