User guide

Chromatographic Checkout 4
Advanced User Guide 79
5
Display the signal output. A stable output at any value
between 12.5 and 750 µV (inclusive) is acceptable.
• If the baseline output is < 0.5 display units (< 12.5 µV),
verify that the detector filament is on. If the offset is still
< 0.5 display units (< 12.5 µV), your detector requires
service.
• If baseline output is > 30 display units (> 750 µV), there
may be chemical contamination contributing to the signal.
Bakeout the TCD. If repeated cleanings do not give an
acceptable signal, check gas purity. Use higher purity
gases and/or install traps.
6 If using a data system, prepare the data system to perform
one run using the loaded checkout method. Make sure that
the data system will output a chromatogram.
7 Start the run.
If performing an injection using an autosampler, start the
run using the data system or press [Start] on the GC.
If performing a manual injection (with or without a data
system):
a Press [Prep Run] to prepare the inlet for splitless injection.
b When the GC becomes ready, inject 1 µL of the checkout
sample and press [Start] on the GC.
8 The following chromatogram shows typical results for a new
detector with new consumable parts installed.
Plunger speed (7683) Fast, for all inlets except COC.
PreInjection dwell 0
PostInjection dwell 0
Manual injection
Injection volume 1 µL
Data system
Data rate 5 Hz
Table 10 TCD Checkout Conditions (continued)