Gustavo P. Ripper, Guillermo Silva-Pineda
A bilateral acceleration comparison between CENAM and INMETRO
A bilateral key comparison was conducted in the area of vibration between the National Institute of Metrology, Standardization and Industrial Quality (INMETRO), Brazil and the Centro Nacional de Metrología (CENAM), in Mexico; with INMETRO acting as pilot laboratory. This comparison was registered in the BIPM key comparison database (Mutual Recognition Arrangement - Appendix B) as SIM.AUV.V-K1.1 and the measurements were carried out by the participating laboratories from October 2004 to March 2006. The aim of this exercise was to compare primary interferometric measurements of complex charge sensitivity of standard accelerometers under sinusoidal linear accelerations in the frequency range from 10 Hz to 10 kHz. In addition, it was intended to provide a link between INMETRO and the key comparison reference values (KCRVs) established in the CIPM key comparison CCAUV.V-K1. This link of the regional metrology organization (RMO) key-comparison SIM.AUV.V-K1.1 to the International Committee for Weights and Measures (CIPM) key-comparison CCAUV.VK1 can be established because CENAM participated in both comparisons. Both participants used automated calibration systems based on homodyne quadrature laser interferometers to measure the sensitivity magnitude and the phase shift of two backto- back standard accelerometers in compliance with the international standard ISO 16063-11:1999.
The results reported by the participating laboratories at 30 specified frequencies and the respective calculated degrees of equivalence are presented. These results show an agreement better than 0,3 % from 10 Hz to 5 kHz and than 1% from 6 kHz to 10 kHz in sensitivity magnitude and better than 0,6D in phase shift in the entire frequency range.