SIMULTANEOUS CALIBRATION OF ACCELEROMETER S AND MECHANICAL SHAKERS INA TRANSVERSE PLANE

The cross-axis sensitivity of accelerometers that is of the order of a few hundredths of the main axis sensitivity, is a common concern in v ibration measurements. Usually the manufacturers do not provide a comp lete information upon the transverse sensitivity of transducers. The t ransverse motion of mechanical shakers is subject to the same problem and lack of information. The method that we present here is aimed at c alibrating at the same time both defaults relatively to the axial comp onents. By mounting an accelerometer on a shaker so that the main moti on is perpendicular to the main sensitivity, its response adds up two products of the same order of magnitude : the main motion x the cross- axis sensitivity and the main sensitivity x the transverse motion. The se two quantities are separated when the accelerometer rotates around the main-motion axis. All relative components of transverse motion and cross-axis sensitivity are derived from a combination of orientations of the accelerometer relatively to the main-motion axis. Measurements made with a variety of accelerometers exhibit a good consistency of t he results concerning the transverse motion of a given shaker. Convers ely, a good reproducibility of results pertaining to the cross-axis se nsitivity of accelerometers has been achieved. The range in which that method is easily used with good results is limited in the low-frequen cy region by the motion of the shaker base and attachment.