Abstract
Modified least squares method (LSM) is developed that take into account errors in input standard signals for calibration of measuring devices. Calibration of the differential pressure gage by the standard control-point setting mechanisms is demonstrated in the paper as an example. The accuracy of the coefficient estimates changes when the errors of the control-point setting mechanisms are taken into account. Using the LSM in the classic form for the mentioned case gives wrong estimation errors in the final estimations of calibration curve coefficients. Therefore, for estimation of errors, characteristics of fractional errors are proposed use and as a variance of estimations errors guarantee the stability of the final estimation values.