KROHNE OPTIFLEX 1100C EN - Manual (Page 52)

6
OPERATION
52
OPTIFLEX 1100 C
www.krohne.com 01/2012 - 4001721801 - HB OPTIFLEX 1100 R01 en
If the parasitic signal 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 menu item 2.5.6 MEAS. AMP.
i Make a note of the amplitude of the correct level signal.
• Go to 2.5.7 MEAS. THRESH.
• Increase the amplitude of the level threshold.
i This value must be more than the incorrect signal. We recommend that you set the level
threshold at half the amplitude of the correct signal.
• Save the settings.
i The threshold increases. It ignores the parasite signal and uses the first signal it finds.
Figure 6-4: Signal intensity/distance graph: thresholds
1 Signal intensity given as a fraction of the reference pulse (measured in thousandths)
2 Distance from the process connection
3 Parasitic signal. A signal from a level switch that is in the limits of the electromagnetic field around the probe.
4 Level signal of the tank contents
5 The level threshold is correct. The device ignores the parasitic signal and measures level correctly.
6 The level threshold is too low. The device can use the parasitic signal as the level signal.