Thermo Scientific 074114, Руководство оператора

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Dionex PDA Operator’s Manual
54
Doc. 065378-01 1/12
1. Open the Chromeleon 7 Command window (see page 31 ) or the Chromeleon
6.8 Commands dialog box (see page 32 ), and select UV .
2. Select NegativeAbsorptionLevel , enter a new setting, and execute the
command.
3. Select Autozero and execute the command to run the autozero routine.
4. Select the LampIntensity command to check the intensity of the deuterium
lamp. The reading should be above 10 million counts for a standard or semi-
preparative cell or above 3 million counts for a semi-micro cell.
If the reading is lower than it should be, select UV_Calibration Intensity and
execute the command to calibrate the intensity of the deuterium lamp.
Afterward, check the lamp intensity again. If the reading is still too low, clean
the flow cell (see
Section 5.2 ) or replace the lamp (see Section 5.7 ).
5. You may continue increasing the negative absorbance level if the range is
required; however, be aware that baseline noise may increase as the negative
absorbance increases.
Negative
Absorbance
Level Approximate Negative
Absorbance at 210 nm Approximate Negative
Absorbance at 240 nm Approximate Negative
Absorbance at 254 nm
0 –2200 mAU –50 mAU –300 mAU
1 (default) –2300 mAU –100 mAU –350 mAU
2 –2600 mAU –200 mAU –450 mAU
3 –2600 mAU –300 mAU –550 mAU
4 –2700 mAU* –400 mAU –630 mAU
5 –2700 mAU* –500 mAU –660 mAU
6 –2700 mAU* –600 mAU –760 mAU
* These signals are saturated and will not report a further negative value.