Densitometer is the equipment normally used to measure the density of radiographic films. It is proposed in this work to develop a method to determine the density of these films by scanning them with the Epson Expression 12000XL scanner.
The development of this technique will make it possible to determine densities of neutron radiographies . Neutron radiographies uses X-ray films in contact with a neutron converter to get the images. The films are irradiated in the J-9 channel of the Argonauta Reactor/SEREA/IEN and the research is carried out in the Neutron Radiography Laboratory/SEREA/IEN.
The first step to get the results is to calibrate in grey levels the image. A standard negative plate in grey levels , that was available from the scanner manufacturer (Figure 1), was scanned and its digital image is obtained. Afterwards, the digital image of the standard will be associated with the digital image of a desirable neutron radiography digital image, both digital images should be scanned at the same conditions. The digital images will be processed using the software Image-Pro Plus 7 .
Figure 1. Gray levels scheme used to calibrate the scanner Epson XL12000 .
It is intended to make the correspondence between grey levels of the digital image and its density. In an optical densimeter, numeric values are assigned from 0 to 3 units of optical density  associated with the amount of light that can pass through an area of the film. As dark is the film, greater is its density.Determining the density of a film, it can be built the sensitivity curve of any radiographic film and can also be found what is the best running time for its irradiation to produce neutron radiographies with the best image quality.
This work has the financial support of Fundação de Inovação e Pesquisa (FINEP) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).
 DOMANUS, J.C. Practical Neutron Radiography, Commission of the European Communities, Kluwer Academic Publishers, 1 ed., 1992.
LASERSOFT IMAGING AG, Silverfast, Germany, 2011-2018.
 MEDIA CYBERNETICS, Inc. Image Pro Manual, Version 10, Copyright, 2019.
 SILVA, J.J.G. Detecção de Microdefeitos por Neutrongrafia Térmica. MSc Thesis, IME (1995).
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