Bio-Rad BioLogic LP System - Manual (Page 90)

5.4.2.4 Manual Override
Many of the operations which the BioLogic LP instruments can perform in Manual mode can also be per-
formed in Run mode. To access these capabilities, press the instrument which is appropriate for the desired
action. The Run Mode Manual Override screens are almost identical to the Manual mode screens and func-
tion in the same way. For a description of how to use these screens, consult section 5.2 Manual Mode.
There are some consequences of using the manual override capabilities which must be understood. The list
below describes the operations which are available, how to accomplish them, and any important information
to know about using the capabilities.
• Event Marks: Using the Event Mark key to draw an event mark on the chart recorder trace will
make an identical mark to the fraction advance marks and will make interpreting the chart recorder
trace more difficult. See section 5.4.3 for additional information.
• Flow Rate: Changing the Flow Rate can be done using the Pump override screen. The new flow
rate will take effect immediately and will last until the next pump step starts. When the next pump
step starts, the programmed flow rate will be used. To make a permanent change to the flow rate,
you must Pause and edit the method, see section 5.4.2.3.
• Fraction Size: Changing the Fraction Size can be done using the Collector override screen and the
Frac Size softkey (the Edit softkey must be used when Thresholds are used). This change is per-
manent unless Collection Windows are in use. When Collection Windows are used, the new
Fraction Size effects only the current or next window. During subsequent windows the fraction size
will be as originally programmed within the method. Since using this capability changes the number
of fractions collected, remember to consider how many tubes are available in the collector.
• Fraction Advance: The fraction collector can be advanced using the Collector override screen and
the Advance softkey. A normal fraction advance (including an event mark and any Delay set) will
occur. Since using this capability changes the number of fractions collected, remember to consider
how many tubes are available in the collector.
Note: When the Advance softkey is pressed, it cannot be pressed again until the fraction advance
actually occurs. This is only applicable and noticed when the Delay setting is greater than 0.
• Collect or Divert: The state of the Diverter Valve can be changed using the Collector override
screen and the Collect or Divert softkey (which key is available depends upon the current state of
the Diverter Valve). When using “Collect All” the override is permanent, however when using other
collection modes the override is not permanent.
In “Threshold”, “Collection Windows”, or “Threshold plus Collection Windows” modes this override
lasts until the Window or Threshold would have the opposite effect. For example, in Threshold
mode, pressing Collect while below the threshold setting causes fractions to be collected until the
UV signal passes above the threshold setting and then back below the setting again. In Threshold
mode, pressing Divert while above the threshold setting causes fraction collection to stop until the
UV signal passes below the threshold setting and then rises above it again. In Collection Windows
mode, pressing Collect before a window starts causes fraction collection to start until the next win-
dow ends. In Collection Windows mode, pressing Divert while inside a window causes collection to
stop until the next window starts. Although the situation is more complex in Threshold plus
Collection Windows, the same rules are applicable. Since using this capability changes the number
of fractions collected, remember to consider how many tubes are available in the collector.
• UV Monitor: The UV Monitor can be controlled exactly like it is in Manual mode, except that the
lamp cannot be turned off.
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System Operation