Laservibrometry

Laservibrometry is a non-contact optical measurement technique used to determine the vibration velocity of a surface. It operates by directing a laser beam onto the vibrating surface and analyzing the frequency shift of the reflected light. This shift, known as the Doppler effect, is directly proportional to the velocity of the surface at the point of impact. The reflected laser light is interfered with a reference beam, and the resulting interference pattern is detected and processed to extract the vibrational velocity information.

The principle of operation relies on the Doppler shift, where the wavelength of light reflected from a moving object changes. If the object is moving towards the laser source, the reflected light will be blueshifted, and if it is moving away, it will be redshifted. Laservibrometers are highly sensitive and can measure very small displacements and velocities. They are also capable of high-frequency measurements, making them suitable for analyzing dynamic vibrations.

There are two main types of laservibrometers: Doppler and heterodyne. Doppler vibrometers use a single-frequency laser and measure the frequency shift directly. Heterodyne vibrometers use two lasers with slightly different frequencies, and the difference in frequency between the reflected light and the reference beam provides the velocity information.

Applications of laservibrometry are widespread across various fields. It is used in mechanical engineering for modal analysis, troubleshooting vibrations in machinery, and quality control. In the automotive industry, it helps in understanding vehicle dynamics and noise, vibration, and harshness (NVH) characteristics. It is also employed in acoustics research, material science for characterizing material properties, and even in medical applications for measuring tiny movements in biological tissues. The non-contact nature of the measurement prevents any influence on the object's vibration, ensuring accurate results.