Metrohm 2.850.9110, Manual, Page: 22 / 44

3.3 Putting the amperometric detector into operation ￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
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2.850.9110 IC Amperometric Detector
3.3.3 Testing the preheating capillary
The amperometric detector is equipped with a preheating capillary in its
interior to ensure that the eluent flows through the measuring cell at a
constant temperature. The preheating capillary need not, however, always
be connected. If the ambient conditions are optimal, then the measuring
results can be sufficiently accurate, even without the use of the preheating
capillary.
CAUTION
The preheating capillary may not be used when working with highly
flammable liquids.
The preheating capillary must be free of both leaks and blockages.
To check whether the preheating capillary is free of both leaks and block-
ages, proceed as follows:
Testing the preheating capillary
1 Connecting the detector inlet capillary
Use a pressure screw (6.2744.014) to fasten the detector inlet capil-
lary to the
Eluent in connector on the detector.
2 Adjusting the settings in MagIC Net
￭
In the program part Manual of MagIC Net, set the maximum
pressure of the high-pressure pump to 5 MPa.
￭
Set the flow rate to 0.1 mL/min.
￭
Start the high-pressure pump.
3 Observe the Eluent to cell connector
After a while, liquid must emerge from the Eluent to cell connector
(wipe up fluid with paper towel).
If no liquid emerges at the Eluent to cell connector, then the pre-
heating capillary is likely to be blocked. To eliminate the problem, see
Chapter Preheating capillary maintenance, page 22 .
4 Observe the pump pressure
Observe the pump pressure display in the program part Manual of
MagIC Net.
A constant pressure should establish itself after a while.