Agilent Technologies 7890A Troubleshooting Manual page 98

8
Troubleshooting Tasks
To Measure a Detector Flow
Measuring FID, TCD, uECD, and FPD flows
WA R N I N G
C A U T I O N
N O T E
98
Hydrogen (H ) is flammable and is an explosion hazard when
2
mixed with air in an enclosed space (for example, a flow meter).
Purge flowmeters with inert gas as needed. Always measure
gases individually. Always turn off detectors to prevent
flame/bead autoignition.
1 Gather the following:
• Appropriate flowmeter adapter tube (can be found in
the GC ship kit)
• Electronic flowmeter calibrated for the gas and flow
rates of concern
To avoid damaging the column, cool the oven before turning off the
column flow.
Set the oven temperature to ambient (35 °C).
2
3 Turn off the column flow and pressure.
4 Turn off (where applicable): the FID flame, FPD flame,
and TCD filament.
Cool the detector.
5
Connect the appropriate adapter to the detector exhaust.
6
Flowmeter tube diameters vary by model; modify the adapter to the
flowmeter tubing as needed.
A rubber adapter tube attaches directly to a uECD, or
TCD exhaust vent.
A separate adapter (19301- 60660) is supplied for the FID.
Insert the adapter into the detector exhaust vent as far as
possible. You will feel resistance as the adapter O- ring is
forced into the detector exhaust vent. Twist and push the
adapter during insertion to ensure a good seal.
Troubleshooting