Detectors; Introduction - ABB PGC2000 Operation And Service Manual

The carrier gas has three purposes: to purge the columns and cell prior to introducing a sample, to
sweep the sample into the detector cell, and to backflush the backflush column. An externally
mounted pressure regulator and gauge regulate the input flow.
The sample system, together with the GCC, controls the calibration sample input. The sample
system flow and pressure control depend on the sample system configuration.

DETECTORS

Introduction

Standard detectors are the Flame Ionization Detector (FID), the Thermal Conductivity Detector
(TCD), and the Flame Photometric Detector (FPD). These detectors may be used separately, in
combination, or as dual detectors. FID and TCD cell subassemblies are located in the upper half of
the oven chamber; the FPD is mounted in a panel on the left side of the analyzer.
The Manual Control Mode screen provides access to detector information and adjustment, as follows:
1. On the Background screen press the F2 (Manual Control) soft key.
2. On the Manual Control Mode screen press the F2 (Detector and Graphics) soft key.
3. The Chroma Board screen (see Figure 4-2) shows detector status and adjustments.
4. For FID and FPD equipped analyzers, operate the ignitor manually by pressing the F4 (Manual
Ignitor On) soft key.
5. For TCD equipped analyzers, set the baseline by adjusting TCD Zero Adjust on the TCD
Amplifier Board (inside the GCC) while watching the Detector Reading on the screen. Turn the
adjustment screw until you reach the minimum value for the Detector Reading.
6. When you finish the detector adjustments and have verified them, press the F1 soft key as
necessary to return to the Background screen.
If an analyzer with an FPD has the FLAME OUT LED illuminated on the front panel, it can be ignited
either automatically or manually. When the Chroma Board screen has Auto or Auto Timeout
highlighted, the ignitor operates as follows:
1. If the temperature zone associated with the FPD is greater than 110 deg C (or the temperature
zone number is set to "0"), the ignitor is turned on for three seconds.
2. The analyzer waits 15 seconds, then checks the state of the flame. If the flame is lit the ignition
sequence is complete.
3. If the flame is not lit, the analyzer repeats steps 1 and 2 (up to six times).
2000-OSM, F1 4-2