Dynamic calibration system for seismometers: Traceability from 0.03 Hz up to 30 Hz

Mechanical calibration and traceability of seismometers in operating conditions are still a technical challenge, since very low-frequency ranges (below 0.1 Hz) involved, sensors under investigation generally heavy bulky. Recently, within the vibration metrology field, some pioneering works proposed to evaluate seismometers’ sensitivity by applying laboratory mechanical procedures, against primary or secondary standards, according ISO 16063 methods. By following this path, at INRIM, it has been developed suitable system for short period horizontal vertical ground velocity 3-axis seismometers. The allows directly sensitivities 2 axes perpendicular gravity with respect (S-waves), derive axis, parallel (P-waves), frequency range between 0.03 Hz 30 Hz.