METHOD OF BISPECTRAL PULSE-FREQUENCY INSPECTION

摘要

FIELD: flaw detection. SUBSTANCE: broadband and narrow band heat waves are excited in sample. Radiation of heat waves is absorbed by IR detector of sandwich type sensitive in two spectral ranges of 2.0-5.0 ??m and 8.0-14.0 ??m. Element sensitive in range of 2.0-5.0 ??m absorbs radiation with low frequency and frequency sigmam on which photosignal has maximum value with phase difference 2pim between it and modulated radiation of source of heat waves is measured. Element of spectral range of 8.0-14.0 ??m measures signal I2 and rate dI2/dtau of its change caused by heat pulse. Thermophysical parameters and depths of laying of flaws are determined by sigmam and relation (dI2/dtau)/I2. EFFECT: enhanced authenticity of method. 2 dwgs