Thermo Scientific 074114, Руководство оператора

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3 • Operation and Maintenance
Doc. 065378-01 1/12
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These settings calculate the absorbance by the following equation:
Where:
I
K
= Light intensity
Offset = Absorbance offset at autozero
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.
Figure 3-8. Caffeine Spectrum
AU = log
avg I
K
300 to 350
> @
avg I
K
270 to 274
> @
--------------------------------------------------- offset in AU (at autozero at 272 nm)
–
1.02
-200
0
250
500
750
1000
1200
220 238 250 263 275 288 300 313 325 338 350 363 375 388 400 413 425 438 450
mAU
nm
mAU
nm
272 nm
Sample Wavelength
Bandwidth = 5 nm
(270 nm to 274 nm)
Reference Bandwidth = 51 nm
(300 nm to 350 nm)
325 nm
Reference Wavelength