JPS5822700B

• Main Authors: IMANAKA NARIKAZU, OKA JUN, FUJII YOSHIHIRO, SUZUKI TAKASHI
• Format: Patent
• Language: English
• Published: 10.05.1983
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC ORINFRASONIC WAVES; MEASURING; PHYSICS; TESTING; TESTING STATIC OR DYNAMIC BALANCE OF MACHINES ORSTRUCTURES; TESTING STRUCTURES OR APPARATUS NOT OTHERWISE PROVIDED FOR

PURPOSE:To accurately monitor generation of flaw in a member to be monitored by comparing the signals of a piezoelectric sensor having flat charactristics through low and high range circuits with the use of a comparator so that the resultant output signals may be recognized as AE count signals. CONSTITUTION:The signals, which are detected by a piezoelectric type sensor 3 having flat frequency characterstics, are amplified by an amplifier 4 and divided into halves so that they are shunted into H.P.F 5 of 200 KHz and H.P.F. 8 of 600 KHz. Then, the respective signals are held at their amplitude peak levels by means of peak hold devices 6 and 9. Then, the signals having passed through the hold device 6 are attenuated to the level preset by an attenuator 7. The output of the hold device 9 and the output of the attenuator 7 are compared by a comparator 10 so that an output may be generated from the attenuator 10 only in case the output from the hold device 9 is higher. The output from the comparator 10 is the AE count signals indicative of the flaw generation.