Low-frequency vibration isolation table FP-1

The FP-1 consists of a large platform, two or three Minus K® SM-1 negative-stiffness vibration isolators, outriggers which connect the platform to the isolators, isolator floor and jack screw plates which help to spread the load on the floor and ballast weights. The FP-1 platform is a heavy steel plate which typically weighs nearly as much as the microscope itself. One reason for this design is to lower the overall system center of gravity to the level of the isolator tilt mechanism, so as to avoid horizontal-tilt coupling, which occurs when horizontal vibrations cause both a horizontal and tilting response of the column. With the system CG at the level of the isolator tilt mechanism, the vibrations are decoupled and better isolation control is achieved. Another reason for the massive platform is that the large total mass of the system helps to diminish any effects from stiff cables and hoses connected to the microscope.