Technical data

152 Understanding Your Agilent ChemStation
7 Calibration
Types of Calibration
Quadratic calibration point weightings, for example, can be used to adjust for
a spread in calibration points. It makes sure that calibration points closer to
the origin, which can normally be measured more accurately, get a higher
weight than calibration points further away from the origin, which may be
spread.
You should base your decision, which kind of calibration point weighting to
use, on your method requirements.
Weight Description
Equal All calibration points have equal weight in the curve.
Linear (Amnt) A calibration point with the amount x has the weighting 1/x normalized to the
smallest amount so that the largest weight factor is 1. Normalization is done by
multiplying the weight with the smallest amount. For example the weight of a
calibration point with the amount x is (1/x) × a where a is the smallest amount
of the calibrated compound prepared in the calibration standards.
If the origin is included it is assigned the mean of the weightings of the other
calibration points.
Linear (Resp) A calibration point with the response y has the weighting 1/y normalized to the
smallest response so that the largest weight factor is 1. Normalization is done
by multiplying the weight with the smallest response. For example the weight
of a calibration point with the amount y is (1/y) × b where b is the response
corresponding to the smallest amount of the calibrated compound prepared in
the calibration standards.
If the origin is included it is assigned the mean of the weightings of the other
calibration points.
Quadratic (Amnt) A calibration point with the amount x has the weighting 1/x
2
normalized to the
smallest amount so that the largest weight factor is 1. Normalization is done by
multiplying the weight with the smallest amount. For example the weight of a
calibration point with the amount x is (1/x²) × a² where a is the smallest
amount of the calibrated compound prepared in the calibration standards.
Quadratic (Resp) A calibration point with the response y has the weighting 1/y
2
normalized to
the smallest response so that the largest weight factor is 1. Normalization is
done by multiplying the weight with the smallest response. For example the
weight of a calibration point with the response y is (1/y²) × b² where b is the
response corresponding to the smallest amount of the calibrated compound
prepared in the calibration standards.
# Calibrations A calibration point is weighted according to the number of recalibrations of the
point. No normalization is done.