Micro-Cell Electron Capture Detector (Μ-Ecd) Theory Of Operation; Epc Detector - Agilent Technologies 6890 Series Service Manual

341 Micro-cell Electron Capture Detector (µ-ECD)
Theory of operation

EPC detector

The EPC version of the µ-ECD detector has one flow line for the anode purge/
makeup gas. After an initial filter frit, the line has a proportional valve
controlled by a pressure sensor. The line splits into two paths, each containing
a non-adjustable restrictor frit. The makeup gas line sweeps past the end of
the column and carries the column effluent into the ECD micro-cell. The
anode purge flow sweeps the upper part of the µ-ECD and cleans sample
deposition from the detector.
Filter
frit
Proportional
valve
Figure 341-2
2 of 26
Anode gas
Pressure
restrictor
control
loop
PS
Makeup gas
restrictor
Pressure
sensor
EPC µ-ECD flow diagram
Detectors
Agilent 6890 Gas Chromatograph Service Manual
Capillary
adapter
Column
Jun 2001