PerkinElmer CLARUS 680 GC User Manual

Setting Up the Detectors
4-28
Setting up a TCD
NOTE: The PPC pneumatics detector gas modules have been set to OFF at the factory.
TCD Overview
The Thermal Conductivity Detector (TCD) is a dual-channel detector that measures
the difference in thermal conductivity between carrier gas flowing through a
reference channel and carrier gas plus sample flowing through an analytical channel
(see the following figure).
Four tungsten-rhenium filaments are connected in a bridge circuit, two in each
channel. The TCD is set up with the same amount of carrier gas flowing through
both channels. The presence of a sample component in the carrier gas flowing
through the analytical channel changes the resistance of the filaments in that
channel. This unbalances the bridge and produces a signal proportional to the
amount of sample.
Figure 4-10. Thermal Conductivity Detector (TCD).

PerkinElmer CLARUS 680 GC Specifications

General

Brand	PerkinElmer
Model	CLARUS 680 GC
Category	Laboratory Equipment
Language	English