IMPACT ACOUSTIC FLAW DETECTOR Russian patent published in 2001 - IPC

FIELD: nondestructive flaw inspection of materials and parts including composite and multilayer ones. SUBSTANCE: flaw detector has striker, sensing element, electromagnet, square-pulse generator, power amplifier, selective amplifier, detector, and pointer instrument. Output of square-pulse generator is connected to input of power amplifier whose output is connected to striker-controlling electromagnet coil. Signal picked off sensing element arrives at input of selective amplifier whose output is connected to detector and output of the latter is connected to pointer instrument. Striker is made in the form of thin blunt needle and sensing element, in the form of hollow needle; striker is placed inside hollow needle to form integrated transducer; upper end of striker is inserted in electromagnet plunger and that of sensing element is fixed to flexible diaphragm; piezoelectric crystal plate is attached to the latter. Comparator input is connected to detector output and light conductor mounted in primary transducer case is connected to comparator output. EFFECT: improved sensitivity and precision of inspection results, reduced noise level. 2 dwg