A laser interferometric vibrometer measures temporal changes in position of objects or surfaces and detects mechanical vibrations at frequencies from 0 to 500 kHz.
The Series SP-S interferometers have additional optics to make measurements on surfaces having arbitrary roughness. The complete system consists of the modularly designed electronics unit with laser, sensor head, and various interfaces. The fiber-optic-coupled interferometer converts motions along the optical axes into interference fringes that are sent to high-resolution, demodulation electronics for processing. Working distances from 30 to 70 mm and 240 mm, with a laser spot diameter of 12 to 30 m and 100 m. The sensor head measures 36 72 72 mm with the signal processing and power-supply unit measuring 150 450 400 mm. Accompanying software includes spectrum analysis and digital filtering, record lengths from 256 to 32,768 data points, computation of speeds and vibrational motions, spectral averaging, and external hardware triggering. The sensor head connects to the electronics unit with a 3-m cable. An optional 10-m cable is available. Piezosystem Jena Inc., 54 Hopedale St., Hopedale, MA 01747, (508) 634-6688, piezojena.com