LOW-COST CAPACITIVE ACCELEROMETERS IN CROSS-EFFECTS

摘要

This work has as main objective to develop a methodology to determine possible interference or cross-effects as well as estimating the uncertainty associated to the calibration of a low-cost measurement system based on capacitive accelerometer-ADXL321, for general purposes. Thus the following steps are proposed: Calibration; identification of the influence variables; definition of the mathematical model for calculation and estimation of uncertainty; and finally, analysis of results. It was examined the accuracy, frequency response function and cross-effects. It was possible to conclude that the measuring system has good accuracy and works properly and similarly to the reference system, that is, it was noted a similar behavior in the main directions and cross-directions for both reference accelerometers, and the studied sensors. The evaluation of the result of expanded uncertainty in relation to cross-effects is: (10.00 ± 0.46) dB for k=2.0 and 95.45% of reliability.