Detectors 5
Advanced Operation Manual 181
Example: Capillary mode (small capillary columns)
If combined column plus makeup flow is between 5 and
10 mL/min, set the reference flow at 3× the combined flow.
For a combined flow between 10 and 15 mL/min, use a
multiplier of 2. This will bring the TCD within 25% of the
maximum response. For further optimization, adjust the
reference flow.
2 m × 0.2 mm capillary column If column flow is 0.75 mL/min,
the makeup must be at least 4.25 mL/min. Set it = 5.
Reference flow will then be 3 × 5.75 = 17.25 mL/min. Total
detector flow = 5.75 + 17.25 = 22.5 mL/min.
25 m × 0.32 mm capillary column If column flow = 10 mL/min,
set makeup low to minimize sample dilution. Set it =
2 mL/min. Reference flow will then be 12 × 2 = 24 mL/min.
Total detector flow = 12 + 24 = 36 mL/min.