FIELD: nondestructive check of thickness of film coats of articles used in mechanical engineering, aviation and other industries. SUBSTANCE: coat of article is acted on by single thermal pulse furnished from linear heat-insulated source. Then time of relaxation of temperature field is determined at point of check of temperature located at fixed distance from line of action of source and initial frequency of furnishing thermal pulses is calculated. Then article is acted on by pulses whose frequency changes adaptively depending on difference between excessive temperature under test and its preset magnitude which is lesser than thermal destruction temperature by 20 to 30 C. At fixed frequency, power of pulses is increased successively in accordance with rated relationship and power magnitudes Qx1 and Qx2 are determined when temperature at point being checked rises to preset limits. Then time of relaxation of temperature field is determined at point of check when article is acted on by single pulses of found power Qx1 and Qx2, respectively, after which thickness of protective coat is calculated by these magnitudes. Device used for realization of this method contains linear thermal energy source 1 located on article 2, temperature detector 3, DC amplifier 4, first electronic switch 5, subtracting unit 6, analog-to-digital converter 7, controllable frequency divider 8, clock pulse generator 9, microprocessor 10, second controllable frequency divider 11, shift register 12, AND logic gate 13, second electronic switch 14, stabilized power supply source 15, third electronic switch 16, comparator 17, fourth electronic switch 18, reference voltage source 19, control signal shaper 20, counter 21, fifth electronic switch 22, differentiating device 23, input-output device 24 and indicator 25. EFFECT: enhanced efficiency. 3 cl, 4 dwg , 1 tbl
