Troubleshooting guide

Lab Exercise: Overview and Diagnostics
Diagnosis View
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Diagnosis View
The 1200 Series ChemStation is equipped with a view to help you: 1) diagnose
systemic problems such as poor retention time precision, 2) perform diagnostic
tests, such as the lamp intensity test, 3) record information pertaining to
instrument maintenance; and 4) provide you with a means to determine when
instrument maintenance should be performed, Early Maintenance Feedback
(EMF). This view is called Diagnosis. In this section, you will explore the
software to become acquainted with its layout and function. In later sections, you
will perform diagnostic tests and maintenance from this section of the software.
Early Maintenance Feedback (EMF)
The Early Maintenance Feedback system allows the user to schedule preventive
maintenance based upon instrument usage. For instance, seals may be replaced
based upon seal wear and the rotor seal may be replaced based upon the number
of valve switches. The analyst inputs usage limits based upon previous
maintenance experience. For instance, if the rotor seal previously failed after
20,000 injections, a limit of 18,000 valve switches might be inserted as the EMF
valve switch limit. When 18,000 injections have been made, the EMF indicator
found in the Method and Run Control or Diagnosis view would change from a
green check mark to a yellow question mark indicating that one of the EMF limits
had been reached. In this part of the laboratory, you will practice inserting EMF
limits and observe the EMF indicator.
1) From the View menu, change to the Diagnosis view. Click on the EMF tool
located near the center of the window. The Memo Pad on the right hand side
of the window will display the EMF information.
2) Select the pump in the drop-down box. To set a limit, highlight the limit
entry box. To test the EMF system, set the seal wear limit 2 units above the
actual seal wear. Note: The seal wear counter increases as a function of both
flow rate and pressure. If your system does not have a column installed, the
pressure will be quite low. In this case you may want to set the flow rate to
2-3 mL/min so that the seal wear counter will change sooner.
3) Return to the Method and Run Control view. Notice that the check mark
on the EMF indicator is currently green. Under the Instrument menu, select
System On or turn the pump on at the System Diagram. In a few moments,
the EMF indicator will change from green to yellow, indicating that one of
the set limits has been exceeded (in this case the seal wear limit).