On-line calibrated measuring systems and their characteristics

Abstract On-line periodic calibration is required in many model-based measuring systems (MSs) working with or controlling engineering objects. Most works on MS calibration focus their attention on description of the calibrated MSs and the calibration algorithms. The choice of the optimum calibration period and other calibration characteristics, i.e the characteristics of the calibration procedure have been practically ignored until recently. This article examines the calibration characteristics in detail and describes methods for determination of their optimal values. The measurement errors of on-line calibrated MSs and their components are analyzed as stochastic functions of time. Two on-line calibrated MSs operating in a butyl rubber synthesis process are described as examples. The principal stages in creating these MSs are considered.