METHOD FOR THERMAL NON-DESTRUCTIVE TESTING OF LARGE CYLINDRICAL PRODUCTS Russian patent published in 2022 - IPC G01N25/72 G01J5/00 

FIELD: non-destructive testing.

SUBSTANCE: invention relates to non-destructive testing of latent defects in heat- and waterproofing skins of large-sized cylindrical products related to the chemical, oil and gas and rocket and space industries using the active thermal method. The method consists in continuous uniform rotation of the control object around its longitudinal axis, simultaneous heating of its outer surface by a heater located along the generatrix of the control object, and registration of the temperature field of the outer surface of the control object by a thermal imager located in such a way that the heated surface of the control object falls into the field of view of the thermal imager at a given point in time. The temperature fields of the surface of the annular zones are recorded with a given overlap along the circumference of the control object, and first the temperature fields of the odd annular zones are recorded, and then the even annular zones, moving the heater and the thermal imager along the axis of the control object from the previous annular zone to the next one relative to the front edge of the test object by distance S = (n-1)×(L-h), where S is the distance between the front edge of the heating strip of the linear tubular heater and the front edge of the test object, m; n is the serial number of the annular zone from the front edge of the test object; L is the length of the heating strip of the linear tubular heater, m; h is the specified value of the overlap of the annular zone along the length of the test object, m. Sequences of full-format thermograms of all the annular zones are saved to a computer, then they are converted into sequences of panoramic images, processed and converted into the resulting map of defects of the test object.

EFFECT: increasing the reliability of control results.

1 cl, 4 dwg, 1 tbl