Optical seismic detector.

摘要

The invention relates to a servo-accelerometer which is particularly suited for use as an optical seismic detector. The servo-accelerometer comprises at least one permanent magnet (17), at least one coil (16) for producing a magnetic field which can interact with the magnet, coil supporting means (15) movable with respect to the magnet, a light source (18), light receiving means (20) for producing a signal indicating the position of impingement of the light beam emitted by the source (18), an optical system (14) mounted on the supporting means for causing the light beam to be focussed on the light receiving means (20), and a servo-amplifier (22) for applying a driving current to the coil (16) in response to the signal from said light receiving means (20).