Computing absorbance data points
1-13
Reference wavelength compensation
A compensated reference wavelength collects wide-band absorbance data in a
region of the spectra where no known analytes exist. It is used to reduce
detector drift and wander, which can affect integration quality.
The detector calculates the compensation value by averaging the absorbance
values within a range of wavelengths that you select. It then subtracts that
value from the absorbance value:
Abs-Comp(
t
) = Abs(
t
) - CRef(
t
)
where
Abs-Comp = absorbance-compensated
Abs = absorbance
CRef = compensation reference
t = elapsed time after start of injection
A starting and ending wavelength defines the compensation reference. CRef
bandwidth must be
≥
40 nm and
≤
100 nm, and fall within a range of 190 to
800 nm.
Tip:
Select a compensation reference range where no analytes are expected to
appear. Since responses are subtracted from the absorbance value, any
responses within the compensation reference range can erroneously affect
quantitative data.
Summary of Contents for 2998
Page 12: ...xii Table of Contents...
Page 26: ...1 14 2998 PDA Detector Optics Principles...
Page 62: ...3 12 Maintaining the Detector...
Page 82: ...5 10 Spectral Contrast Theory...
Page 96: ...A 14 Safety Advisories...
