Teledyne GC-Pro/TCD - Gas Chromatograph - Manual (Page 26)

Operational Theory GC-Pro TCD
Teledyne Analytical Instruments 12
Figure 2-1: Internal Temperature Controllers
The sample chamber contains the 10-port GC switching valve and 2
sample loops. The ‘TC Sensor’ chamber contains the thermal
conductivity sensor. The ‘COLUMN’ is housed in a separate
‘COLUMN’ enclosure and maintained at a temperature of 70° C.
Chamber temperatures have been set at the factory however they can be
changed by the user from the Settings/Thermocouple/Settings screen as
described in Section 4.5.7.2. The actual temperature setpoint for your
instrument may be different depending on the application. It is listed in
the Addendum and Testing Results section of Appendix C.
2.3.2 Gas Flow Control System
The analyzer is equipped with ports for the introduction of carrier
gas, span, and sample gas. Depending on the application and the options
chosen, some instruments may have a separate port for admitting a purge
gas.
It is imperative that the sample, carrier and span gases be supplied at
constant pressure using two stage stainless steel diaphragm gas
regulators. The recommended pressure range is 30 to 80 psig for sample
and carrier gas; the span gas should be supplied at a pressure of 20 psig