Bio-Rad BioLogic LP System - Manual (Page 72)

5.3.5.2 Threshold Collection Mode
Threshold Collection mode allows you to only collect peaks by defining a threshold value in absorbance
units (AU). When the absorbance is above the threshold value the Diverter Valve sends the fluid to the frac-
tion collector and the collector advances as programmed. When the absorbance is below the threshold
value the Diverter Valve sends the fluid to waste. To prevent air bubbles and noise from being collected as
peaks there is an optional Bubble Filter. This filter can be set to High, Medium, Low, or Off. As the setting is
increased broader peaks are considered air bubbles or noise and are not collected. When the filter is Off,
all peaks are collected. The units used for the fraction size are either time (minutes) or volume (ml),
depending upon the choice made when the method was created. Table 19 describes how to program
Threshold Mode.
Table 19.
Program Mode’s Fraction Collector Table: Threshold Collection
Reference Description
Fraction Size: Enter the fraction size desired using the number
keys. The OK softkey confirms the fraction size entered and
continues to the threshold and bubble filter entry screen. The
Cancel softkey displays the Select Collection Mode screen.
Threshold and Bubble Filter: Enter the threshold using the
number keys. The Set BF softkey will increment the bubble fil-
ter setting through a circular list. The OK softkey confirms the
threshold and bubble filter entered and softkeys display the
Fraction Collection Table for Threshold mode. The Cancel soft-
key displays the Select Collection Mode screen.
Fraction Collection Table for Threshold mode: This table
shows the current fraction mode and the collection parameters.
To change the parameters press the Edit softkey. To display
the Method List press the OK softkey.
Note: To program the Pump Table or the Alarm Table without
returning to the Method List press the Pump and Alarm keys
respectively while viewing the Fraction Collector Table.
65
System Operation
Method: Volume: 1.00 ml
Enter Fraction size: 1.00ml
CANCEL OK
F3
F3a
(return
to F1)
Method: name Volume: 1.00 ml
THRESHOLD MODE Frac size: 1.00 ml
Thresh: 1.5000 AU Bubble Filter: Off
EDIT OK
F3b
P5
(return
to F1)
Method: name Volume: 1.00 ml
Threshold: 2.0000 AU
Bubble Filter: Medium
SET BF CANCEL OK
F3a
F3b
(return
to F1)
Press to select
between Low,
Medium, High, and Off