Bomem-GRAMS User's Guide

Appendix D
Glossary
preprocessing
Mathematical treatment applied to a spectrum before the calibration model
is applied to it. There are a number of standard preprocessing algorithms
commonly used in spectroscopy.
primary method
The accepted standard laboratory technique for measuring the properties of
samples. When developing a calibration model, the “known” property
values of the training set samples are determined by measurement using
the primary method.
property
A single, measurable characteristic of a sample, whether it be a physical
property such as temperature or a chemical property such as concentration.
raw spectrum
1. A spectrum that has not undergone any mathematical alterations.
2. A single-beam spectrum.
reference spectrum (also called background spectrum or zero spectrum)
A single-beam spectrum that only contains information about the analyzer,
including the sample accessory and the air present in any part of
the modulated beam optical path. This is required in order to obtain
a transmittance or absorbance spectrum of the sample.
A reference spectrum is obtained by removing the sample from the sample
accessory or by filling the sample accessory with a blank sample and
acquiring a spectrum.
repeatability
The precision of repeated measurements on the same instrument.
reproducibility
The precision of repeated measurements on different instruments.
resolution
The smallest frequency interval that can be distinguished over a spectral
range. The lower the resolution setting on the spectrometer, the more data
points there are in the spectrum.
54 Bomem-GRAMS User's Guide