350 Flame Photometric Detector (FPD)
Theory of operation
2 of 36
Jun 2001
Detectors
Agilent 6890 Gas Chromatograph Service Manual
Figure 350-1 Schematic of a flame photometric detector
Single wavelength FPD
The single wavelength FPD is a single burner module with one PMT housing.
Either sulfur or phosphorus can be detected by installing an appropriate
optical filter in the PMT housing.
The sulfur filter is blue/purple and transmits at 393 nanometers.
The phosphorus filter is yellow/green and transmits at 525 nanometers.
Makeup
H
2
Air
Filter
frits
Proportional
valves
Pressure
sensors
Restrictors
Shield
Vent
PMT
Wavelength filter
Window
Emission zone
PS
PS
PS
Pressure
control loops