Agilent Technologies 6850 Series II User Information page 78

4.
Noise, wander and drift
1.
Path
View
View/Data Analysis/Report/Specify Report
View/Method/Save Method As
Instrument menu/Edit Parameters
View/Run Control/Sample Information
2.
3.
4.
5.
6.
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8.
9.
Released: March 2004
With the flame lit, observe the FPD signal at the display. This is the
flame-on background offset. A stable value < (Flame off + 85) display units
is acceptable.
If the value is < 5 display units, verify that the electrometer is on. If it was
off, recheck the flame-off background offset. If it was already on, your
detector requires service.
Make these settings on the ChemStation:
Press Start to make a blank run, then wait until it is finished.
Select View/Data Analysis. Load the data file for the blank run just
completed.
Select Report/ Specify Report. Choose printer and screen.
Select Integration/ Integrate.
After integration is completed, Select Report/Print Report. The
report will list measurements for noise (peak to peak, % standard
deviation, and ASTM) and for drift and wander.
Base signal should be:
Flame off
Flame on
ASTM noise should be < 5 display units.
Wander (for a 2-minute time window) should be < 2.5 display units.
6850 Series II GC User Information
Setting
Full Menu
Performance + noise, OK
System Suitability, Edit Noise Ranges, enter sev-
eral ranges that >1.01 min plus one at 5 min,
OK
Supply name
Oven, initial temp 60°C
Initial time = 12 min, Rate 1 = 0°C/min, OK
Enter directory and file names, close window
≤ 40 display units
≤ Flame off + 85 display units
Verifying Performance
FPD Checkout
page 78 of 256