Tcd Pneumatics; Tcd Carrier, Reference, And Makeup Gas - Agilent Technologies 7820A Advanced User's Manual

TCD pneumatics

Frit
Valve
PS = Pressure Sensor

TCD carrier, reference, and makeup gas

Advanced User Guide
The figure below shows the pneumatics design of the TCD.
Makeup Reference gas
Frit
Valve
PS
Frit
Reference and makeup gas must be the same as the carrier gas,
and the gas type must be specified in both the inlet and detector
parameter lists.
When using packed columns, we recommend a small makeup
gas flow (2 to 3 mL/min) to get the best peak shapes.
Use the next figure to select a value for reference gas flow for
either capillary or packed columns. Any ratio within ±0.25 of
that in the figure is suitable.
EPC/EPR Module
Frit
Valve
PS PS
Frit
5
Detectors
Vent
Reference
switching valve
Column
73