Transfer of Near-Infrared Multivariate Calibrations without Standards

A novel approach to the transfer of multivariate calibration is proposed. This method is based on the finite impulse response (FIR) filtering of a set of spectra to be transferred, using a spectrum on the target instrument to direct the filtering process. Often, the target spectrum is the mean of a calibration set. The method is compared against direct transfer and piecewise direct transfer on near-infrared reflectance spectra in two representative data sets. Results from these studies suggest that FIR transfer compares favorably with piecewise direct transfer in terms of accuracy and precision of the match of transferred spectra to the predictive calibration models developed on the target instrument. Unlike piecewise direct transfer, FIR transfer requires no measurement of standard samples on both the source and target spectrometers. Details and current limitations of the FIR transfer method are presented.