Setting Temperatures For The Nickel Catalyst Tube - Agilent Technologies 7890 Series Advanced Operation Manual

4
Columns and Oven
C A U T I O N

Setting temperatures for the nickel catalyst tube

166
Table 41 Gas flows for a TCD/FID series installation
Gas
Carrier (helium)
TCD switching flow
FID hydrogen
FID air
Hydrogen flow is pressure-controlled, where an FID provides a
known resistance. The nickel catalyst tube increases flow
resistance, so that the calibration is no longer valid. You must
measure hydrogen flow with a bubble or similar meter.
The nickel catalyst can be damaged by exposure to air.
The nickel catalyst tube is usually mounted in the back inlet
position and controlled by the back inlet temperature
setpoint. For most analyses, set these temperatures:
• Nickel catalyst tube—375 °C
• FID—400 °C
Flow rate, mL/min
30
25
45 (see Caution)
500
Advanced Operation Manual