My Forth Review for Sensors Journal

Another interesting article Giganto, S.; Martínez-Pellitero, S.; Cuesta, E.; Meana, V.M.; Barreiro, J. Analysis of Modern Optical Inspection Systems for Parts Manufactured by Selective Laser Melting. Sensors 2020, 20, 3202. concerned with optical measurement systems for surface accuracy was reviewed by me in May 2020 for MDPI Sensors (ISSN 1424-8220) Journal.

The article`s abstract is: Metal additive manufacturing (AM) allows obtaining functional parts with the possibility of optimizing them topologically without affecting system performance. This is of great interest for sectors such as aerospace, automotive, and medical–surgical. However, from a metrological point of view, the high requirements applied in these sectors constitute a challenge for inspecting these types of parts. Non-contact inspection has gained great relevance due to the rapid verification of AM parts. Optical measurement systems (OMSs) are being increasingly adopted for geometric dimensioning and tolerancing (GD&T) verification within the context of Industry 4.0. In this paper, the suitability (advantages and limitations) of five different OMSs (based on laser triangulation, conoscopic holography, and structured light techniques) for GD&T verification of parts manufactured by selective laser melting (SLM) is analyzed. For this purpose, a specific testing part was designed and SLM-manufactured in 17-4PH stainless steel. Once the part was measured by contact (obtaining the reference GD&T values), it was optically measured. The scanning results allow comparing the OMSs in terms of their inspection speed as well as dimensional and geometrical accuracy. As a result, two portable systems (handheld laser triangulation and structured blue-light scanners) were identified as the most accurate optical techniques for scanning SLM parts.

My short review is below: It was very nice to get acquainted with the material of your article.
A very competently constructed and verified article containing a deep introduction, with a good overview; clear statement of the problem; a description of the test sample, which is a set of nodes of various sizes, which allows one to judge about the degree of debugging of additive technologies and the requirements for optical hardware for metrological support; and, finally, a clear analysis of various metrological technologies, reduced to criteria that determine the quality of the final product. I believe that the article can be published as it is.