Bomem-GRAMS User's Guide

Appendix D
Glossary
blank sample
A sample that does not absorb infrared radiation within the spectral range
where the measurement is performed.
calibration
The process of aligning analyzer measurements to agree with reference
measurements obtained using a primary method.
calibration (or model or calibration model)
The set of equations that represents the relationship between the absorbance
spectra of a set of samples and the properties of the samples.
Some common types of models are peak height, peak ratio, PLS and
autosubtract models.
calibration set (or training set)
In spectrometer calibration, a set of standard samples used in calibration
model development. The calibration set covers the expected ranges of
property values, as well as any other variations that may affect the spectra,
such as temperature. When there is more than one property, the calibration
set must include independent variations of each property.
channel
An optical channel on the spectrometer. Each channel is associated with one
sample accessory and one detector. Some spectrometers have only one
channel. This is typical of laboratory instruments.
Some spectrometers have multiple channels. This allows one instrument to
analyze several streams simultaneously.
If the sampling system is set up for stream switching, one channel can be
used to analyze two or more streams. In most cases, however, there is only
one stream (i.e. one sampling point) per channel.
channel spectrum
A spectral artifact caused by reflections in the gap between two optical
surfaces, for example, between parallel window surfaces or at the coupling
point between optical fiber ends. Also called Fabry-Perot interference.
Bomem-GRAMS User's Guide 49