A Simple Portable Magnetometer Based on Magnets and Hall-Effect Sensors Capable of Measuring Magnetic Properties
Round 1
Reviewer 1 Report
-- Abstract - Add the full name of the device (is it "analogue-to-digital converter"?) for AD-AD22151.
-- Abstrat - Should it be "has a sensitivity THAT can be adjusted"?
-- Line 65 - Strange wording "in it was attached on which".
-- Line 67 - The description of (3) talks about "iron base". Some further explanation should be provided for the clearly visible large screws?
-- Fig. 1 - The description of numbers 1,2,3 etc. should be listed in the caption of the figure.
-- Line 74 - Strange wording "nearby this magnet this magnet."
-- Line 89 - The +1.2% sensitivity variation was the total variation? Related to some temperature changes? Explain in more detail.
-- Line 92 - Value of C2 is not given.
-- Line 127 and Fig. 3 - Number 9 is not shown in Fig. 3.
-- Fig. 1a - Use "Voltage" instead of "tension".
-- Fig. 4b - There is no description in text of the large peak at 4 Hz. How such a peak would influence the results? What is the meaning of "Average noise > 60 Hz" for the curve which extends from 1 Hz?
-- Fig. 4b - Use proper SI notation which is "Hz", not "hz".
-- Equation (1) - The "M" appears to be written so that it follows zero in the index. This is clearly incorrect.
-- Fig. 4c - The "c" in "(C)" on the picture should be lower case, not capital letter.
-- Table 1 - All the values of sensitivities in the text were given with V/T (and also in Table 2). Therefore, express the values in Table 1 also in tesla, not gauss.
-- Equation (2) - Use middle-high dot to represent multiplication.
-- Equation (2) - Introduce/explain all the symbols.
-- Equation (3) - Introduce all the symbols.
-- Equation (4) - What is calculated in equation (4)? Add the right-hand-side term (as in equation (3)).
-- Table 2 - Why the values listed in the table are only below 0.29-0.33 T? The graph in Fig. 5 suggests a much wider range. Explain.
-- Line 209 - Use the word "inset" not "increment".
-- Line 241 - Fig. 6 does not show a magnetization curve.
-- Line 251 - It is stated that "existence of high resolution magnetometers [...] prevents the application of this study"? Prevents? How? Explain?
-- Line 283 - SI units should be the main units. Also, the Authors should be more diligent when using the SI prefixes and other units. The correct version of "kilo" is "k" (lower case). The correct version is "Hz", etc.
-- Literature - Full paper titles should be included when citing other papers.
-- There is is no treatment on the positioning errors due to imprecision of various screws. This should be analysed with more details as to the effect on the accuracy of measurements.
Author Response
Dear Reviewer 1, we would like to thank you for the valuable review of our paper.
-- Abstract - Add the full name of the device (is it "analogue-to-digital converter"?) for AD-AD22151.
R. Thanks for the observation, but that was a Hall effect sensor and not an analogue-to-digital converter.
-- Abstrat - Should it be "has a sensitivity THAT can be adjusted"?
R. Thanks for the observation, the detail was provided as requested.
(Page 1 - Lines 25-26)
(Page 2 - Lines 91-92)
-- Line 65 - Strange wording "in it was attached on which".
R. Thanks for the observation, the detail was provided as requested.
(Page 2 - Line 74)
-- Line 67 - The description of (3) talks about "iron base". Some further explanation should be provided for the clearly visible large screws?
R. Thanks for the observation, the sentence has been repaired.
(Page 2 - Line 76)
-- Fig. 1 - The description of numbers 1,2,3 etc. should be listed in the caption of the figure.
R. Thanks for the observation, the detail was provided as requested.
(Page 3 – Lines 109-113)
-- Line 74 - Strange wording "nearby this magnet this magnet."
R. Thanks for the observation, the detail was provided as requested.
(Page 2 – Lines 83-84)
-- Line 89 - The +1.2% sensitivity variation was the total variation? Related to some temperature changes? Explain in more detail.
R. Thanks for the observation, the phrase is not about sensitivity error but about repeatability. This sentence has been removed from the text.
-- Line 92 - Value of C2 is not given.
R. Thanks for the observation, the detail was provided as requested.
(Page 3 – Lines 100-101)
-- Line 127 and Fig. 3 - Number 9 is not shown in Fig. 3.
R. Thanks for the observation, a description of the sample holder is in the text and the indication is in figure 3 (b).
(Page 4 – Lines 143-145)
(Page 5 – Line 152)
-- Fig. 1a - Use "Voltage" instead of "tension".
R. The word tension was not found in the text only Voltage as suggested by the reviewer.
(Page 2 – Line 89)
(Page 3 – Line 109)
(Page 5 – Line 157)
-- Fig. 4b - There is no description in text of the large peak at 4 Hz. How such a peak would influence the results? What is the meaning of "Average noise > 60 Hz" for the curve which extends from 1 Hz?
R. Thanks for the observation, the text was rewritten in the manuscript to better explain figure 4b which shows the noise of the magnetometer reading system and not a signal-to-noise ratio. The text in the 60 Hz legend in the figure has been removed. The graph in Figure 4b has been replotted
(Page 5 – Lines 161-163)
(Page 6 – Line 204)
-- Fig. 4b - Use proper SI notation which is "Hz", not "hz".
R. Thanks for the observation, we have made the replacement.
-- Equation (1) - The "M" appears to be written so that it follows zero in the index. This is clearly incorrect.
R. Thanks for the observation, we made the substitution of M for mz correcting the problem mz means the magnetization in the z axis.
(Page 6 – Line 173)
-- Fig. 4c - The "c" in "(C)" on the picture should be lower case, not capital letter.
R. Thanks for the observation, we have made the replacement.
-- Table 1 - All the values of sensitivities in the text were given with V/T (and also in Table 2). Therefore, express the values in Table 1 also in tesla, not gauss.
R. Thanks for the observation, we have made the replacement.
(Page 6 – Lines 209-210) Table 1
(Page 8 – Line 254) Table 2
-- Equation (2) - Use middle-high dot to represent multiplication.
R. In the equation 2 m.r represents a scalar product between two vectors and not a multiplication.
-- Equation (2) - Introduce/explain all the symbols.
R. Thanks for the observation, the detail was provided as requested.
(Page 7 – Lines 219-220)
(Page 7 – Line 225)
-- Equation (3) - Introduce all the symbols.
R. Thanks for the observation, the detail was provided as requested.
(Page 7 – Lines 225-227)
-- Equation (4) - What is calculated in equation (4)? Add the right-hand-side term (as in equation (3)).
R. There’s no need for equation 4 in the text, all this information is well described in the manuscript. In this way we remove equation 4.
-- Table 2 - Why the values listed in the table are only below 0.29-0.33 T? The graph in Fig. 5 suggests a much wider range. Explain.
R. These magnetic field values in Table 2 are related to the maximum magnetic field values obtained by the built magnetometer. We simply selected the 4 highest values that are close to the saturation magnetization of the nickel sphere for comparison with the values obtained in the commercial magnetometer.
-- Line 209 - Use the word "inset" not "increment".
R. Thanks for the observation, we have made the replacement.
(Page 8 – Lines 272)
-- Line 241 - Fig. 6 does not show a magnetization curve.
R. The Fig. 6 represents magnetic maps of induced magnetic field. After obtaining these maps it is possible to obtain the magnetic moment and then a magnetization curve.
The sentence has been rewritten to clarify these points.
(Page 8 – Lines 278-280)
-- Line 251 - It is stated that "existence of high resolution magnetometers [...] prevents the application of this study"? Prevents? How? Explain?
R."The existence of high resolution magnetometers and complex theoretical models prevents the application of this study in basic physics." Because high-resolution magnetometers such as the SQUID magnetometer are expensive equipment and this is not the reality of many basic physics teaching laboratories.
The sentence was rewritten.
(Page 9 – Lines 329-330)
-- Line 283 - SI units should be the main units. Also, the Authors should be more diligent when using the SI prefixes and other units. The correct version of "kilo" is "k" (lower case). The correct version is "Hz", etc.
R. A manuscript revision was performed.
-- Literature - Full paper titles should be included when citing other papers.
R. Thanks for the observation, we have made the modification to the references of all cited papers.
(Page 11-12 – Lines 385-459).
-- There is is no treatment on the positioning errors due to imprecision of various screws. This should be analysed with more details as to the effect on the accuracy of measurements.
R. Thanks to the Reviewer for this approach, but a more detailed look at the accuracy of the measurements are beyond the scope of this paper. What we have would be a repeatability analysis of measurements that are between approximately 20% error in repeatability. We intend to present another version of this work already with better measurements and a new approach, an evolution of this magnetometer should be published soon with these points.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
nice paper with regard to a magnetometer for education, e.g. in schools, where a budget is always problematic.
I have only two comments:
Line 16) use mT instead of Gauss
Line 68) 109mm
Line 187) Equation 3: should it not be 3*µ0/(4*pi)
line 197) Equation 4: should it not be 3*µ0*a3/2
Author Response
Dear Reviewer 2, we would like to thank you for the valuable review of our paper.
nice paper with regard to a magnetometer for education, e.g. in schools, where a budget is always problematic.
I have only two comments:
Line 16) use mT instead of Gauss
R. Thanks for the observation, the detail was provided as requested.
(Page 1 – Line 22)
Line 68) 109mm
R. Thanks for the observation, magnet support base (cylindrical shape) of 30 mm diameter and approximately 109 mm long, shown in Figure 3b is a part that makes up the built magnetometer.
(Page 4 – Lines 136-137)
Line 187) Equation 3: should it not be 3*µ0/(4*pi)
R. The y-axis magnetic field component of equation 3 does not have a 3 multiplicand.
line 197) Equation 4: should it not be 3*µ0*a3/2
R. Thanks for the observation, there’s no need for equation 4 in the text, all this information is well described in the manuscript. In this way we remove equation 4.
Author Response File: Author Response.pdf
