320
Nitrogen Phosphorus Detector (NPD)
Theory of operation
sensor, and a non-adjustable restrictor frit. The makeup gas and hydrogen
lines merge before entering the detector.
Air in
H
in
2
Makeup in
Figure 320-2
2 of 32
Filter
Proportional
Pressure
frits
valves
sensors
PS
PS
PS
Pressure
control loops
EPC detector flow
Detectors
Agilent 6890 Gas Chromatograph Service Manual
Restrictors
Vent
Electrically
heated
bead
Jun 2001