Verifying Performance
TCD Checkout
Released: March 2004 6850 Series II GC User Information page 58 of 256
Offset checkout
Display the signal output to determine background offset. A stable offset at any
value between 0.5 and 30 display units (inclusive) is acceptable.
• If the offset is < 0.5 display units, verify that the detector filament is on. If
the offset is still < 0.5 display units, your detector requires service.
• If offset is > 30 display units, there may be chemical contamination con-
tributing to the signal. Perform a thermal cleanout (see “Thermal cleaning
(bakeout)” on page 185 for details). If repeated cleanings do not give an
acceptable signal, check gas purity. Use higher purity gases and/or install
traps.
Noise, wander and drift
1. Make these settings on the ChemStation:
2. Press Start to make a blank run and wait until it is finished.
Oven
Initial temp 40°C
Initial time 0 min
Rate 1 25°C/min
Final temp 90°C
Final time 0 min
Rate 2 15°C/min
Final temp 170°C
Final time 2 min
Path Setting
View Full menu
View/Data Analysis/Report/Specify Report Performance + noise, OK
System Suitability, Edit Noise Ranges, enter sev-
eral ranges that >1.01 min plus one at
5 minutes, OK
View/Method/Save Method As Method name
Instrument Menu/Edit Parameters Oven, verify oven temp = 40°C
Initial time = 12 min, Rate 1 = 0°C/min, OK
View/Run Control/Sample Information Enter directory and file names
Table 17. TCD Checkout Conditions (Method TCDCKO) (Continued)
To Next Page
Loading...
