Preventive Maintenance
Electron capture detector (ECD)
remove the column to the ECD. If a capillary column was installed, remove also the makeup gas adapter in the detector base.
2.Disconnect the carrier gas source line at its fitting on the HP 5890.
3.Using a Vespel ferrule, and adapters as necessary, connect the carrier source line to the detector base, including any traps in the line.
4.Set carrier pressure to about 7 kPa (1 psi) and check for flow through the detector.
5.Leaving the oven door open, enter any temperature for the detector up to 250^C.
6.Enter the following:
DET | A ( or B ) ON |
SIG 1 
( or 
SIG 2 
) ( 
A 
or 
B 
)
7.Within 15 minutes, displayed signal values should be within the range 40 to 100 (400 to 1000 Hz); there may be downward drift.
8.If displayed values are greater than this range, trap(s) may be at fault. Connect the carrier gas supply line directly to the detector base and repeat the test.
If values are now within range, trap(s) are likely at fault; if still out of range, the carrier gas supply itself may be contaminated.
Leaks
Note: This test assumes that flow system components upstream from the detector (inlet, column) are leak•free.
1.Set inlet, oven, and detector temperatures to ambient and allow time for cooling. Turn off the detector, and turn off its carrier flow.
2.Use a vent plug (Part No. 5060•9055)to cap the ECD exhaust vent.
3.Set carrier gas pressure at the inlet to the instrument to 103 kPa
(15 psi). Open the carrier gas mass flow controller fully to ensure that
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