Proceedings of the KIEE Conference (대한전기학회:학술대회논문집)
- 2000.07c
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- Pages.2195-2197
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- 2000
Basic Study for the fabrication of Laser Doppler Vibrometer for the Detection of Ultrasonic
초음파 측정용 레이저 도플러 진동계의 제작에 관한 연구
- Kim, Seung-Jong (Dept. of Electrical & Electronics Eng. Chung Ang Univ.) ;
- Kim, Myoung-Sun (Dept. of Electrical & Electronics Eng. Chung Ang Univ.) ;
- Kim, Ho-Seong (Dept. of Electrical & Electronics Eng. Chung Ang Univ.)
- Published : 2000.07.17
Abstract
In order to detect the ultrasonic that is generated by the partial discharge of the heavy electric machinery a Laser Doppler Vibrometer (LDV) is developed. A Michelson type interferometer which employed heterodyne signal process technique is built to measure the frequency and amplitude of vibration. The output signal of the fast photodetector is a frequency modulated signal centered at 40 MHz. The signal from the detector is amplified and converted to intermediate frequency centered at 1 MHz after mixing process. The voltage output that is proportional to the velocity of the moving surface(PZT) is obtained using PLL. The spectrum of the FM signal is analyzed and integration method was introduced to obtain amplitude information. This LDV can be used to measure the vibration of MEMS devices, automobiles, HDD and CDP.
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