Computed tomography (CT) is one of the most commonly used modern methods for non-destructive testing of composite materials. Considering increased application of composite materials in many industries, more advanced tests are required to accurately estimate material behaviour due to mehanical loading. Computed tomography is a radiological method that uses the beam of ionizing radiation to determine external and internal structure of the measuring object. Moreover, informations about the geometry and the microstructure of the observed object are available when proposed measurement method is applied. Various noise and uncertainities, caused by different external and internal factors, are generated while acquiring radiographs with the CT device which can directly affects the quality of the obtained 3D volumes. Since registered 3D scans are series of digitally recorded images, measurement of the entire displacement and strain fields can be performed on the reconstrucetd volumes applying the Digital Volume Correlation (DVC), based on the already established Digital Image Correlation (DIC). However, in addition to measurements on the surface of the test sample, the DVC method allows us to access the material response within the test sample. Within this work the 3D volume of the uniaxial dog bone sample was conducted. The device used for this test was industrial μ-tomograph NIKON XT H 225. The dog bone sample was made of the mat glass fibers embedded in epoxy resin. The acquisition of the 3D scans was performed two times consecutively when the sample was in unloaded state. 3D volume was then recontructed from the recorded 2D projections. Afterwards, the DVC method was applied to measure displacement and strain fields within the dog bone specimen. In this work, global DVC algorithm Correli C8, based on the finite element method, was used. The aim was to observe the influence of the noise and uncertanities on finite element size, for measuring displacements and strains, was then observed from measured data. The objective of this work is to determine the standard displacement and strain resolution for different size of C8 finite elements. Registered values of the standard displacement and strain resolution, analyzed in the unloaded sample, are very important for further mechanical testing via μ-tomography. The smallest increase of the displacement and strain values, considering the applied finite element size, that can be measured with the proposed technique are defined by accessing the standard displacement and strain resolution.