Metrohm 896 Professional Detector – Amperometry - Manual (Page 28)

4.4 Testing the detector output capillary
￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
20 ￭￭￭￭￭￭￭￭
2.896.0020 896 Professional Detector – Amperometry
To check whether the preheating capillary is free of both leaks and block-
ages, proceed as follows:
Testing the preheating capillary
1 Connect the detector input capillary
Use a pressure screw (6.2744.014) to fasten the detector input capil-
lary to the connector Eluent in on the detector.
2 Adjust 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 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 29.
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.
4.4 Testing the detector output capillary
The detector output capillary must be of a certain length in order to be
able to generate sufficient backpressure. The required length is dependent
on the flow that has been set. The table 1 shows the recommended
lengths, as determined by the set flow.
Table 1 Recommended lengths for the detector output capillary
Flow Capillary length ( ⌀0.25 mm)
2.0 mL/min 0.5…1.5 m
0.5…1.0 mL/min 1.0…2.5 m
0.25 mL/min 3 m