Threshold Detection; Threshold Detection - Teledyne Foxy R1 Instruction Manual

3.3.5 Threshold Detection

Figure 3-13 Threshold detection cuts peaks when external
peak signal exceeds set percentage
Foxy
5. Enter the Flow Delay volume as 1 to 999 counts using the
arrow icons. The Up and Down Arrows increment or decre-
ment the numbers, the Left and Right Arrows move the
cursor position.
To calculate the number of pump counts for the delay vol-
ume:
= (  4  D
P
counts
= (0.7854  D
P
counts
Where L is the tubing length and D is the inside diameter.
P is the volume delivered for each pump count. Round to
vol
the nearest whole number.
Note
For the greatest possible flow delay volume accuracy, cut the
tubing so that it holds a multiple of the of the pump count vol-
ume.
6. Touch the Enter icon to return to the Methods Settings
menu.
Threshold detection isolates the most concentrated portion of
peaks. The threshold is set as a percentage of the maximum
input signal. When the input signal rises above this threshold
value, the fraction collector performs a tube advance to isolate
the peak.
An example of threshold peak detection and collection is shown
in Figure 3-13. The peaks on the analog signal are numbered 1
through 4. The fraction collector ignores the first peak because it
is below the 10% threshold. It isolates peaks 2 through 4 in col-
lection tubes because the peak signal exceeds the threshold.
1
Time
® ®
R1 and Foxy R2 Fraction Collectors
Section 3 Programming
2  L)  P
, otherwise expressed as:
vol
2  L)  P
vol
2
3
Isolated Peaks (grey)
4
3-15