| Title |
Development of High Resolution Laser Doppler Vibrometer |
| Authors |
김성훈(Kim, Seong-Hun) ; 고진환(Go, Jin-Hwan) ; 김호성(Kim, Ho-Seong) |
| Keywords |
LDV ; high resolution ; fringe counting ; electronic counting ; phase comparison |
| Abstract |
A high resolution Laser Doppler Vibrometer(LDV) developed using electronic fringe counting method. The fringe pattern signal obtained via analog signal processing is divided into two. One was converted to a TTL signal with a ZCD(zero-crossing detector) and then counted to calculate the displacement due to the vibration. The other was directed to the A/D converter to get a high resolution of about Λ/320 with the phase comparison method. The data obtained with the A/D converter was used in the displacement calculation and the result was displayed on a LCD pane. In this study, a Laser Doppler Vibrometer with measurement range of 0.32μm~129μm and displacement resolution of 2nm, about Λ/320 , was developed. And this LDV can be used to measure the dynamic of microsize devices such as MEMS(Micro Electro-Mechanical Systems) and to diagnose high capacity electric equipment such as circuit breakers and transformers, of which resonant frequencies are changed when they are damaged. |