Development of a tri-axial primary vibration calibration system

Abstract

A tri-axial primary vibration calibration system has been set up at National Institute of Metrology for simultaneous calibration of motion transducers. The system is driven by three electrodynamics exciters that are mounted along the three orthogonal axes. The cross-coupling unit based on air bearing is developed for force transferring and motion guiding. Spatial orbit vibration is composited from sine vibration components of the three orthogonal axes. Relationship of shapes and orientations of spatial orbits and amplitudes and phases of sine vibration components is discussed. Multi-exciter vibration control for both cross-coupling compensation and amplitudes and phases control of sine vibration components is investigated. The tri-axial measuring system can simultaneously measure the three orthogonal vibration quantities based on the band-pass sampling method. The experiments show that a variety of spatial orbits can be generated by efficiently reducing the cross-coupling of the tri-axial vibration exciter and the magnitude and the phase shift of sensitivities of a tri-axis accelerometer can be determined.