The invention relates to a noninvasive analyzer and a method of using information determined at least in part from in-vitro spectra of tissue phantoms or analyte solutions to aid in the development of a noninvasive glucose concentration analyzer and/or in the analysis of noninvasive spectra resulting in glucose concentration estimations in the body. The preferred apparatus is a spectrometer that includes a base module and a sample module that is semi-continuously in contact with a human subject and that collects spectral measurements which are used to determine a biological parameter in the sampled tissue, such as glucose concentration. Collection of in-vitro samples is, optionally, performed on a separate instrument from the production model allowing the measurement technology to be developed on a research grade instrument and used or transferred to a target product platform or production analyzer for noninvasive glucose concentration estimation.