OPERATION
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95
OPTIFLEX 1300 C
www.krohne.com
01/2008 • 4000172301 - HB OPTIFLEX 1300 R02 en
How to use thresholds
If there is a parasite above the level and the threshold is too low, the instrument can incorrectly
use it as the level signal.
If the parasite is smaller than the correct level, you can manually change the threshold to find
the signal. This procedure tells you how to change the level threshold to find the correct signal:
•
Look at the signal screen in operator mode.
i
Find the likely position of the parasite and the level signals. Make a note of the ampltitude
of each signal in volts.
•
Go to supervisor mode > advanced setup > installation setup > level threshold
supervisor mode > advanced setup > installation setup > level threshold
supervisor mode > advanced setup > installation setup > level threshold
supervisor mode > advanced setup > installation setup > level threshold
i
You will see this screen:
NOTE!
Although the data that follows refers to the level threshold, it is applicable for interface
threshold and probe end thresholds.
Figure 6-10:
Voltage/distance graph: thresholds
1
Voltage amplitude of the signal in Volts
2
Distance from the process connection
3
Parasite signal (from a level switch)
4
Level signal of the tank contents
5
The level threshold is correct. The instrument ignores the parasite signal and measures level correctly.
6
The level threshold is too low. The instrument can use the parasite signal as the level signal.
+2
0
-2
0
+1
+0.5
1
2
3
4
5
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HB_OPTIFLEX1300_EN_D4_080428.book Page 95 Tuesday, April 29, 2008 2:47 PM