What are some specific challenges in calibrating accelerometers?
A. Transverse motion introduced by the excitation system or calibration shaker is a common source of error. Shakers are structures and have modes of vibration, just like anything else. With traditional mechanical flexure-based exciters, the undesired transverse motion of the shaker can be more than 100% more than the desired primary axis motion. This large cross-axis excitation motion, coupled with a small transverse sensitivity in accelerometers, can cause an undesirable “glitch” at certain frequencies in the calibration curve. Also costly and troublesome with older calibration systems, is the sheer amount of time it takes to perform calibration. Some older systems can take more than 10 minutes per axis – providing for lots of “hurry up and wait!” Finally, ISO 17025 compliance of the calibration certificate can be a challenge. While the standard sets specific guidelines for calibration certificates, interpretation of this can be overwhelming. Unfortunately, not all calibration softwar
