Setting Parameters For The Tcd - Agilent Technologies 7890 Series Advanced Operation Manual

5
Detectors

Setting parameters for the TCD

180
Press [Front Det] or [Back Det].
1
Set the detector temperature. Do not set higher than the
2
maximum temperature allowed for the column because part of
the column passes through the heated block and into the cell.
Verify that makeup gas type is the same as that plumbed
3
to your instrument (next to Makeup line in the parameter
list). Change the gas type, if necessary.
Set the reference gas flow rate.
4
If you are using packed columns, turn off the makeup gas
5
(or proceed to step
carrier, reference, and makeup gas"
proceed to step 7
6 If you are using capillary columns:, choose a flow mode
and set the makeup gas flow or combined flow.
Turn on the filament. Allow about 30 minutes for thermal
7
stabilization. A longer period may be needed for the
highest sensitivity.
If necessary, turn Negative polarity [On/Yes] to invert
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negative- going peaks. When a sample contains
components giving both positive- and negative- going
peaks, Negative polarity can be switched on and off during
a run as a timetable event.
Example: Packed mode (packed and large capillary columns)
Column flow is 15 to 60 mL/min. Set the reference flow to
1.5 times the sum of column flow + makeup flow.
Makeup gas is recommended with all capillary columns. It
allows the column to be inserted all the way into the
detector and withdrawn 1 mm. If makeup is not used, the
column must be no more than 3 mm above the ferrule.
Minimum makeup flow is 1 mL/min.
1/8-inch stainless steel column If column flow is 30 mL/min,
set the reference flow to 30 × 1.5 = 45 mL/min. Total
detector flow is 30 + 45 = 75 mL/min.
10 m × 0.53 mm column If column flow is 15 mL/min and
makeup flow = 2 mL/min, set the reference flow to 1.5 × (15
+ 2) = 25.5 mL/min. Total detector flow is 17 + 25.5 =
42.5 mL/min.
6 and enter 2 to 3 mL/min, see
on page 176) and
Advanced Operation Manual
"TCD