Seismometers are widely used all over the world, but rarely calibrated traceably. PTB analysed its capabilities for seismometer calibration and identified its multi-component acceleration exciter as suitable for carrying the comparably heavy seismometers. Additionally, multi-axial seismometers can be calibrated in all axes without moving the device. The calibration device needed to be analysed and tested for the required small excitation magnitudes and low excitation frequencies. The results show that it is capable of generating small sinusoidal excitation of less than 1 mm/s in a frequency range down to 0.4 Hz. For this purpose, the feedback control needed to be adapted. Additionally, a temperature control of the shaker armature prevents the problem of temperature increase due to hot hydraulic fluids near the armature. The vibrations in all three translational degrees of freedom are measured by laser vibrometers and then processed according to ISO 16063-11 by sine fit procedures.
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