Thermo Scientific Dionex ICS Series Operator's Manual page 59

These settings calculate the absorbance by the following equation:
AU = log
Where:
I
Offset = Absorbance offset at autozero
1.02
1200
mAU
1000
750
mAU
500
250
0
-200
220 238 250
Sample Wavelength
Bunch Width
The bunch width setting determines how many nanometers are averaged when
collecting 3D data. The default is 1 nm. Selecting a bunch width above 1 nm will
reduce the required data storage by approximately the reciprocal. Do not select a
bunch width when the spectrum of the compound has a fine structure; the bunch
width will reduce the spectral resolution.
Doc. 065378-01 1/12
avg I 300 to 350
K
-------------------------------------------------- - offset in AU (at autozero at 272 nm)
avg I 270 to 274
K
= Light intensity
K
Bandwidth = 5 nm
(270 nm to 274 nm)
263 275 288 300 313
272 nm 325 nm
Reference Wavelength
Figure 3-8. Caffeine Spectrum
3 • Operation and Maintenance
–
Reference Bandwidth = 51 nm
(300 nm to 350 nm)
325 338 350 363 375 388
nm
nm
400 413 425 438 450
51