The relevance and nature of a new technology for measurement of vibrational displacement of a material point through normal toward the object plane are stated in the article. This technology provides registration and processing of images of a round mark or a matrix of round marks, which are applied to the surface of a control object. A measuring signal here is the module of radius increment of the round mark image at vibrational blurring of this image. The method for calculation of the given error of measurements, as a function of a number of pixels of the round mark image, has been developed and proven in the present research. The results of pilot studies are given. Linearity of transformation of the measured size into a measuring signal has been proven. The conditions of a technical compromise between the field of view area of a recording device during distribution measurement of vibrational displacements along the surface of a control object, and the accuracy of this measurement are determined. The results are illustrated with numerical examples of calculations of the given error of measurements in the set field of view and the one at the given maximum set error of measurements.
With the aim to compare methods for counting the number of lines of a raster matrix, intersecting a round mark image, and a number of pixels belonging to this image for measuring its radius, a numerical simulation is carried out in the present article. It is proved that the application of the method for counting the number of pixels belonging to the image of the round mark allows obtaining more than 30 times gain in the accuracy of this image radius measurement using the same equipment. The formulas proposed in the article are used for software implementation of non-contact vibration measurement systems.