Ultrasonic testing

The flaw detector is intended for defects detection in both rails along the running surface and rail cross-section, except for the rail base blades using flaw detection trolley during complete testing, and for the confirmatory testing of separate rail cross-sections and welded joints by means of manual probes.

UDS2-77 ultrasonic single rail flaw detector is a mechanized trolley intended for the inspection of one rail line.
The flaw detector utilizes a unique scanning scheme that allows testing the entire rail section, except for foot flanges, by pulse echo, echo-shadow and echo-image techniques.

The ОКО-22М-UT ultrasonic flaw detector is a standalone electronic unit and is intended for application in high-performance automated multi-channel NDT Systems, transportable systems (mechanized NDT systems) or for manual testing.

Available in several flaw detector models that are different in number of channels and in a volume of built-in functions for results processing.

UD3-71 flaw detector is an ultrasonic general-purpose flaw detector which is intended for:

  • manual non-destructive testing of products for detection of defects such as discontinuity and inhomogeneity of material in raw stock, finished items, in-process goods, welded, soldered, bolt, riveted and other joints;
  • measurement of defects depth and depth coordinates;
  • measurement of various items thickness at one-way access to them;
  • measurement of signals (reflected from defects) amplitudes ratio;
  • measurement of equivalent defects dimensions;
  • assessment of sound velocity in sundry materials.

UD4-76 universal ultrasonic flaw detector-tomograph with a large high-contrast TFT display is intended for products testing for detection of defects, such as discontinuity and inhomogeneity of materials, goods and in-process goods, welded joints, measurements of signals amplitude ratio from defects, of depth and their depth coordinates. Tomograph function enables to display and store testing results in the form of B-scans with reference to the scanning path. Flaw detector also solves the task of items thickness measurement at one-way access. Several operating modes for DGS diagrams are provided too, what makes it possible to define conveniently and quickly equivalent defects dimensions.

UD4-76 universal ultrasonic flaw detector-tomograph with large high-contrast TFT display is intended for products testing for detection of defects, such as discontinuity and inhomogeneity of materials, goods and in-process goods, weld joints, measurements of signals amplitude ratio from defects, of depth and their depth coordinates. Tomograph function allows to display and store testing results in the form of B-scans with affixment to scanning path. Flaw detector also solves the task of items thickness measurement at one-way access. Several operating modes for DGS diagrams are provided too, what makes it possible to define conveniently and quickly equivalent defects dimensions.

Over few decades TOFD method is widely used for fast and reliable UT of welded joints. TOFD offers great accuracy for measuring the critical size of crack-like-defects. The accuracy of better than ±1mm can be obtained in a wide range of material thickness.

Over few decades TOFD method is widely used for fast and reliable UT of welded joints. TOFD offers great accuracy for measuring the critical size of crack-like-defects. The accuracy of better than ±1mm can be obtained in a wide range of material thickness.

ТUZ-5 portable manual ultrasonic thickness gauge is intended for on-the-fly measurement of thickness of products made from different materials and sound velocity measurement with one-sided access to them.

Ultrasonic non-destructive testing technique for flaw detection is based on propagation and reflection of high-frequency (0.5 to 24 MHz) UT waves in a test object (steel, plastic, composites, rubber, etc.), with their further processing and visualizing on a special-purpose NDT instrument (flaw detector).

This method is used to search for material defects (pores, hairlines, inclusions, inhomogeneities, etc.) and to control workmanship quality like welding, soldering, etc. Ultrasound examination is a mandatory procedure for manufacturing and operation of numerous critical parts, such as aircraft motor parts, main pipelines or rails.


Basic UT techniques are as follows:

  • Pulse echo technique is the most common: a single probe generates UT waves (i.e. acts as transmitter) and receives back the signals reflected from defects (receiver). This method has been widely practised due to its simplicity, since only one probe is required, which means that there is no need for special fixtures during manual testing (as compared to TOFD), or alignment of acoustic axes when two probes are used. Besides, it is one of the few ultrasonic NDE procedures that allow for quite accurate measurement of defect coordinates, such as depth and location in a test object (in relation to the probe).
  • Echo image technique (“Tandem”, “Duet”) utilizes two probes from one side of a test item, so generated waves are reflected from a flaw towards the receiver. In practice, it is used for recognizing defects that are located perpendicularly to the tested surface, e.g. cracks;
  • Time-of-flight diffraction technique (ToFD) utilizes two probes from one side of a test item which are placed opposite to each other. If a defect has sharp edges (for instance, cracks), UT waves are diffracted on the defect ends and reflected in all directions, also towards the receiver. The ultrasonic machine records the arrival time of both pulses at their sufficient amplitude. The instrument screen simultaneously displays both signals from upper and lower boundaries of the defect, thereby enabling to make a rather precise estimation of the conditional height of the defect. TOFD inspection is a sufficiently multipurpose technique that allows ultrasonic testing of welds of any complexity, but it requires specialized fixing devices for probes, as well as a tester capable of operating in such mode;
  • Echo shadow technique is used for examination of products having two parallel faces, whereas analysis is made for echoes reflected from the opposite side. Similarly to through-transmission technique, a defect is evidenced here by the loss of reflected waves. But in contrast to through-transmission technique, the echo shadow method is featured by easy access to the test object from one side only.