Modeling for error reduction in vibrating beam accelerometers

The author discusses the various performance error sources in vibrating beam accelerometers and how the model used affects those errors. The data given are from Sundstrand Data Control's RBA-500 accelerometer. The design goal in the RBA-500 has been to achieve minimum cost, size, and weight while relying on good symmetry and crystal matching to provide the common mode error rejection necessary to reach acceptable tactical grade performance. Two force crystals are necessary to reduce errors to reasonable levels. It is noted that various models are available with different accuracies and computational demands, but the microprocessors coming on line should have no trouble handling the task at high sample rates. The chosen model can be massaged to reduce selected errors.<>