Bio-Rad BioLogic LP System - Manual (Page 85)

5.4.1.1 Errors Which Prevent the Start of Runs
The errors listed below can prevent a method from being run.
• A Required Valve is Missing: A valve which is necessary for the method to run is not present. To
resolve this error the valve indicated must be connected to the Controller, or the method must be
edited to omit any use of the valve indicated. The OK softkey returns to Manual Mode with the
Pump active.
• The Flow Rate Exceeds Pump Calibration: The flow rate programmed within at least one step in
the method cannot be reached with the current tubing and calibration. To resolve this error, one or
more of the following must be done:
1) the pump tubing must be changed,
2) the pump must be recalibrated, and/or
3) the flow rate within the method must be reduced.
The OK softkey returns to Manual Mode with the Pump active.
• The Delay Exceeds the Fraction Size: The current Delay setting is larger than the smallest
Fraction Size within the method. To resolve this error, either the delay setting must be reduced or
the fraction size must be increased. The Change softkey will display the Delay entry screen. The
Cancel softkey cancels the start of the run and returns to Manual Mode with the Pump active.
• The UV Lamp is Not On: The UV Lamp was turned off. The Change softkey turns on the lamp
and returns to the Countdown screen. The Ignore key leaves the lamp off and proceeds to the
Countdown screen. If the lamp remains off, the UV trace on the chart recorder will not reflect actual
run data; however the event marks will still be drawn.
• The Bypass Valve is set to Bypass: The Bypass Valve is currently set to bypass the column. The
Change softkey changes the valve to the Column position and proceeds to the Countdown screen.
The Ignore softkey leaves the valve in the Bypass position and proceeds to the Countdown screen.
The Ignore option allows the Bypass Valve to be used for some other purpose if desired.
Note: The BioLogic LP will run a method even if the UV Monitor Flow Cell and Conductivity Monitor Flow
Cell are not connected to the Controller. If either of these are not connected then the chart recorder trace(s)
will not reflect actual run data although the UV trace will show the event marks. The BioLogic LP cannot
determine if a fraction collector or chart recorder are connected and will assume that they are connected. To
avoid problems, check these components before starting a run.
5.4.1.2 Using the Delay Feature
The Delay feature is used to coordinate the UV Monitor signal and event marks on the chart recorder with
the fractions collected. The fluid in the UV Monitor flow cell does not actually reach the fraction collector
immediately because it has to pass through the tubing, the Conductivity Flow Cell, and the Diverter Valve
first. The Delay is defined as the period in which the fluid is moving through the path from the UV Flow Cell
to the Fraction Collector Drop Head.
When the Delay is set to a value greater than 0, each fraction advance is delayed by the value set after the
event mark is drawn to allow the fluid in the UV Monitor Flow Cell to travel to the Fraction Collector Drop
Head. In this way the fluid generating the UV Monitor signal at the time the event mark is drawn is actually
the first fluid delivered to the corresponding fraction in the collector. When the Delay is set to 0, the event
mark and the fraction advance occur simultaneously, and the first fluid collected in the fraction is not the fluid
generating the UV Monitor signal.
Determining the correct Delay setting requires that you know the volume of the fluid path between the UV
78
System Operation