A system for the generation of static and very low-frequency reference accelerations

Accelerometer calibration instruments usually exploit linear motion to generate accelerations with frequencies ranging from a few hertz up to several kilohertz, While the high-cutoff frequency depends on the resonance condition of the mechanical system, the low-cutoff frequency is limited to the length of the mechanical motion. When tests at very low frequencies are required, some difficulties arise since the displacement needed is too long. To overcome this problem, a system based on the centrifugal acceleration of rotary motion has been developed. The system generates accelerations whose frequency is adjustable from 0 to 2 Hz and whose amplitude can be adjusted from 0 to 500 m/s(2). A description of the system and of the experimental test is given.