Installation; General Precautions; Mounting The Detector On The Gc - Valco Instruments Co. Inc. TCD Instruction Manual

Installation

General Precautions

Mounting the Detector on the GC

The detector is usually mounted on top of the GC column oven. The power
cord for the controller is 1.8 m (6') long; the detector cable and the signal
output cables (attenuated and unattenuated) are 1.2 m (4') long.
•
Do not turn the unit on until the carrier gas is flowing through the detector.
•
Do not shut off or disconnect the carrier gas when the detector is hot,
even if the unit is turned off. Turn off the power switch on the back of the
controller and allow the detector to cool down naturally before disconnect-
ing or shutting off the carrier gas.
•
Position the controller unit where the mains switch on the rear panel can
be reached easily.
Vertical Mounting
The detector has no particular orientation
requirements, but it should have adequate
thermal isolation from the column oven and
injection port. Most GCs have an existing
opening which will allow the TCD2 to sit
vertically on top of the column oven with the
column inlet extending into the oven. If you
are replacing an existing detector, you can
usually just remove it and set the TCD2 in its
place. If not, use a drill or chassis punch to
drill a hole of the proper size, and set the
detector in position.
While trying to match base plate mounting holes to every GC on the market
is impractical, we have located the mounting holes so that at least two of
them will coincide with existing holes on the GC. (Refer to Figure 5.)
Orient the detector to allow for easy cable and gas connections. The inlet
lines installed into the detector must enter the column oven and permit
column connection. Temperature loss between the column outlet and the
detector should be minimized to prevent possible condensation of the
sample.
CAUTION: Do not mount the detector near the column
oven cool-down vents.
Horizontal Mounting
Some older GCs have access to the column oven through the side of the
GC. This does not present a problem as far as operation of the TCD2 is
concerned. Drill a hole at the appropriate location, orient the detector for
convenient connection, and mark the position of the mounting holes. Drill the
mounting holes and secure the detector to the side of the GC with four sheet
metal screws (not supplied).
CHANNEL
A
VENT
CHANNEL
A
INLET
(gold ferrule)
Figure 6: Detector connections
9
CHANNEL
B
VENT
CHANNEL
B
INLET
(stainless ferrule)