Thermo Scientific 074114, Руководство оператора

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3 • Operation and Maintenance
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Reference Wavelength
The reference wavelength is the center wavelength of the reference intensity
determination. Absorbance is measured by comparing the reference intensity to
the sample intensity. Selecting a reference wavelength implies a reference mode
for each of the single wavelengths being collected. There are two types of
reference mode: “active” or “off.”
•
To select the active reference mode, enter a wavelength within the selected
sample scanning range of the Dionex PDA. The selected wavelength will be
used as the reference wavelength. The reference intensity will vary over time,
as the signal intensity changes.
For maximum compensation, select a reference wavelength from the same
lamp as the sample wavelength. For example:
If the sample wavelength is 272 nm, you might select a reference
wavelength of 325 nm because both wavelengths are within the UV
spectrum (190 to 380 nm) of the deuterium lamp.
Figure 3-6. Effect of Bandwidth on Baseline Noise
-0.0500
-0.0400
-0.0300
-0.0200
-0.0100
0.0000
0.0100
0.0200
0.0300
0.0400
0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00
mAU
min
1
2
3
3
2
1
WVL:254 nm
Bandwidth = 1
Noise = 26
P
AU
Bandwidth = 4
Noise = 16 AU
P
Bandwidth = 8
Noise = 14
P
AU