Technical note: Optimum predictive search method for automatic acoustical instrument calibration

摘要

Acoustical measuring instruments such as sound level meters, require periodic calibration to comply with noise control regulations. For laboratories that are involved with calibrations of acoustical instruments, it is desirable to develop automatic or semiautomatic calibration systems that are economically attractive. The purpose of this note is to discuss a new optimum predictive search method developed for acoustical instrument calibrations. In this method, the instrument setting-reading response is modeled as a time-invariant unknown system response. Previous measurement data (settings and readings taken from the instrument) are used to estimate the system model parameters. The desired setting is then predicted according to the estimated system model, The search for the optimum becomes solving a linearonlinear system equation. This fast optimum search algorithm can be used in other automatic measurement systems with substantial reduction in calibration time. The automatic calibration system developed has a precision that is better than a manual calibration system, and the uncertainty of the measured relative sound pressure level is within +/- 0.1 dB, (C) 1998 Institute of Noise Control Engineering. [S0736-2501(98)00406-8]. [References: 5]