The LSV laser-interferometric vibrometer from SIOS Messtechnik GmbH, supplied in the UK by Armstrong Optical, offers accurate, non-contact determination of temporal changes in the positions of objects or surfaces of arbitrary roughness. It detects mechanical vibrations at frequencies ranging from 0 to 500kHz with subnanometer resolution.
These instruments have been designed around the industry proven SP-S Series laser-interferometric vibrometers. The working distance of the LSV-Series vibrometer can be adjusted continuously in a wide range by a zoom objective with a working distance of between 240mm and 2.5m. The complete system consists of a compact fibre optic-coupled sensor head, a modular electronics unit incorporating a HeNe laser, and various interfaces. The fibre-coupled interferometer converts motions along the optical axes into interference fringes that are transmitted to fast, high-resolution, demodulation electronics for processing. Operation and display of results employs a PC running specialised data-analysis software.
The modular nature of the system and the separate measurement head ensures that accurate and highly resolving measurements can be performed even in aggressive environments. The great strength of the system is its ability to make measurements over large distances from vibrating surfaces with low reflectivity.