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This is the final report for CIPM key comparison CCAUV.V-K3 in the area of 'vibration' (quantity of acceleration). The aim of this comparison was to measure the voltage sensitivity of one accelerometer standard set with primary means at 27 frequencies from 0.1 Hz to 40 Hz. Fourteen Metrology Institutes from five RMOs have participated in the comparison with National Institute of Metrology, P.R. China as pilot lab and Laboratoire National de Métrologie et d'Essais and National Metrology Institute of South Africa as co-pilot labs. One quartz-flexure servo accelerometer of single-ended type and a signal conditioner was circulated among the participants. All but one of the participating laboratories provided their calibration results, which were mostly consistent within their declared expanded uncertainties for magnitude results. Only two participants failed to contribute to the KCRV values calculated for five frequencies. For phase shift, three participants could not contribute to the calculation of the KCRV values in a total of sixteen frequencies. This first low-frequency vibration key comparison revealed the current calibration capabilities of the fourteen participants of five RMOs. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCAUV, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

To investigate the dynamic characteristics of high-sensitivity graviinertial devices (accelerometers, seismometers, and others) it seems advantageous to use for the input signal the gravitational acceleration produced by bodies with a known mass distribution. This eliminates the need for moving the transducer under investigation. Such motion is needed in the inertial acceleration reproduction as well as for inclining a measuring instrument in the Earth's gravity field. Error in measuring the parameters of the transducer motion is determined by the uncertainties of the length- and angle-measuring instruments being used. Particularly, it concerns the angle measurement errors when the gravity field effects have been taken into account. The existing methods for reproducing gravitational acceleration are based on the use of nonuniform fields of simple shape bodies (sphere, cylinder, and the like). These methods require calculation of the corresponding acceleration, taking into account the spatial mass distribution of the instrument sensing element. The commonly employed approximation results in a procedural error of the order of 10% and over. It is proposed to calibrate a measuring instrument using a uniform, flat gravity field of varying direction. The set-up designed to realize this method reproduces varying accelerations over the frequency range 0.01 to 0.3 Hz with amplitude less than 1.3 × 10−7 m/sec2. This enables calibration of seismometers of various types with a higher accuracy.

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