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Low-frequency acceleration standard measuring device (LF acceleration standard, 0,4 Hz to 63 Hz)

Working Group 1.71

This acceleration standard is the national standard for the realization of the unit of acceleration (and the associated scale) at sinusoidal vibration of a solid body in the frequency range from 0,4 Hz to 63 Hz. 

At sinusoidal accelerations free from distortion, the measurands velocity and displacement are generated at the same time so that, in connection with the laser interferometer, the units of the three translational motion quantities (acceleration, velocity and displacement) are realized. 

The maximum displacement amplitude is 80 mm, the maximum acceleration amplitude 15 m/s2. The amplitudes of the motion quantities are measured with a relative measurement uncertainty of 0,1 %. 

The sensitivity (magnitude) of precise accelerometers (reference and transfer standards) can be measured with a measurement uncertainty of 0,2 % by primary vibration calibration using laser interferometry in accordance with ISO 16063-11. 

At frequencies of 0,5 Hz or higher, the comparison method (secondary vibration calibration in accordance with ISO 5347-3 and ISO 16063-21) can be applied, the measurement uncertainty then being 0,5 %.

Low-frequency acceleration standard measuring device (0,4 Hz to 63 Hz)

The low-frequency acceleration exciter with air bearing (stroke of 0,16 m), the laser interferometer and the vibration isolation system are sub-systems of this LF acceleration standard.

The sub-systems associated with the LF acceleration standard for 0,1 Hz to 20 Hz are used to derive the acceleration amplitude from the interferometer signals and to measure the electrical output quantities of calibration objects.