The influence of different vibration exciter systems on high frequency primary calibration of single-ended accelerometers

Abstract

During the monitoring of the long term stability of two accelerometers intended for use in the CIPM Key Comparison CCAUV.V-K2, significant deviations of the magnitude results of the single-ended transducer were discovered. These deviations depend on whether the calibration was performed on an armature made of beryllium or of ceramic. Further investigations showed that this effect must be attributed to some not yet readily understood dynamic process between the contact surfaces of the accelerometer and the armature. The relative motion underlying the deviations has a significant systematic influence already at 5 kHz and beyond. Therefore, the effect needs to be considered in some way while comparing results within the key comparison, as some laboratories use beryllium armatures and some use ceramic armatures.The contribution describes the details and outcome of the investigations performed on the topic so far and is intended to trigger the necessary discussion on consequences and solutions.

Intrinsically accurate sensing with an optomechanical accelerometer

“…As with all primary accelerometer calibrations, [38][39][40][41][42] there are many parasitic dynamic effects that can lead to systematic errors. For instance, we found that it was important to consider non-rigid body motion of the accelerometer package.…”

A proposal to minimize the dispersion on primary calibration results of single-ended accelerometers at high frequencies

“…Bruns et al [5] have reported the comparison of charge sensitivity results of a single-ended (SE) accelerometer B&K 8305-001 on two different vibration exciters: a PTB modified version of the Bouche shaker (VE) and a SPEKTRA SE-09 shaker. The results obtained exhibited a systematic deviation which increased with rising frequency, starting at 5 kHz.…”

“…This has been reported by Dr. Thomas Bruns in 2009, during the IMEKO TC 22 technical meeting in Lisbon. Later on, two articles related to this problem were published in Metrologia [5] [6].…”

Extension en basse fréquence et amélioration des incertitudes du banc d’étalonnage primaire des accéléromètres

“…Les écarts constatés entre les étalonnages menés dans les deux configurations sont inférieurs à la somme Des écarts de l'ordre de 1 % à 10 kHz entre des étalonnages réalisés avec deux excitateurs de conception et de matériau différents ont déjà été observés par d'autres [5]. Ils ont également été constatés entre des éta-lonnages réalisés avec des raccords différents [6].…”