Definition of the reasons of damages of details of pipelines, coppers

Visual and measuring control - the simplest and at the same time informative control method. It is the only method of nondestructive control, which can be carried out and is often carried out without any equipment or carried out with use of the elementary measuring means. It allows to reveal a superficial time and cracks, undercuts, craters, prozhog, fistulas, flows, shifts of edges and other defects. It is possible to refer low probability of detection of minor superficial defects, and also dependence of detectability of defects on subjective factors (visual acuity, fatigue, experience of the expert who is carrying out control) to shortcomings of a method and control conditions (illumination, optical contrast, etc. ) . Nevertheless simplicity, small labor input and a certain informational content of visual and measuring control do it obligatory and preceding carrying out nondestructive control by other methods. Whatever unique were methods and means of the subsequent control operations, control of products begins a naked eye with visual survey. At distance, optimum for eyes, - 250 mm distinguish details the size ~ 0,15 mm, however possibilities of an eye are limited at survey of the remote, moving, insufficiently lit objects.