Doc No.
4
November 2018
III.
Troubleshooting Tips
Flow restriction or blockage from detector cell or backpressure coils should be eliminated
first to avoid irreversible damage to the suppressor.
Detector Cell Backflush:
Bypass the suppressor and connect the column
outlet
tubing to the detector
cell
outlet
port and direct the detector cell
inlet
tubing to waste.
□
Turn on the pump and flow eluent at the application flow rate for 10 minutes.
Turn off the pump. Re-measure the detector cell backpressure by following
the steps in
Section I
above.
□
Note:
Repeat the backflush procedure if the backpressure remains high. If the
backpressure of the detector cell doesn’t come below
70 psi after multiple attempts,
replace the detector cell.
Backpressure Coil Adjustment:
If the pressure is greater than 40 psi for carbonate eluent or other eluents,
trim the backpressure coil and repeat the backpressure coil test in
Section I
.
□
If it is less than 30 psi for carbonate eluent or less than 10 psi other eluents,
add more tubing and repeat the backpressure coil test in
Section I
.
□
Note:
Backpressure coils help to prevent gases generated during AutoSuppression from
out-gassing by compressing the bubbles. The bubbles can be occasionally trapped in the
detector cell causing noise. For example, carbonate eluent is suppressed to carbonic acid,
which is CO
2
gas in equilibrium with DI water, and CO
2
gas can come out of solution if
adequate pressure is not applied. Therefore, we highly recommend the addition of 30-40
psi for carbonate eluent or 10-40 psi for other eluents.
Suppressor Backflush with DI Water:
Turn off the pump and disconnect the column
outlet
and cell
inlet
tubing from
the suppressor eluent ports (if not already disconnected).
□
Connect the DI water tubing from the pump
outlet
directly to the suppressor
eluent
out
port and direct the
eluent in
tubing to waste. (Effectively plumbing
the eluent ports backwards to reverse flow through the eluent chamber).
□
Turn on the pump and flow DI water at 1.0 mL/min for 4 mm suppressor and
0.25 mL/min for 2 mm suppressor for 10 minutes. Turn off the pump. Re-
measure the suppressor backpressure by following the steps in
Section II
.
□
Note:
Repeat the backflush procedure if the backpressure remains high. If the
backpressure of the suppressor doesn’t come below 200 psi after multiple attempts,
replace the suppressor or contact your Service Engineer or Technical Support team.
