User's Manual

5-11
Edition 1. Ref. No: 307010E
Using the Display Panel
5.7 Disturbance Echo Handling
5.7.1 Setting up a Noise Threshold Table
If the transmitter has locked to a disturbing echo you can create a Noise Threshold
Table in order to suppress the disturbing echo:
1. Do the following to check where the disturbing echo is located and the corre-
sponding radar signal amplitude:
1. Choose sub menu [1-1] and set the Output Parameter to Ullage.
2. Note the Ullage value.
3. Choose sub menu [1-1] and set the Output Parameter to Amplitude.
4. Note the Amplitude value.
5. Choose sub menu [1-1] and set the Output Parameter to the desired
value (see the Key Parameter list).
Now you can start creating the noise table.
2. Choose sub menu [6-1].
3. Specify the number of points you want to use for the Noise Threshold Table.
In order to suppress a single peak signal four points is sufficient. For more
complicated noise tables you can use up to ten points.
4. Choose sub menu [6-2] and enter the ullage values that correspond to the
desired noise table break points. The points must be added in consecutive
order. Use a margin of ± 0.3 meter, see illustration below.
5. Choose sub menu [6-3] and enter the amplitude threshold values that corre-
spond to the desired noise table break points. A margin of + 5 dB is suffi-
cient in most cases.
+ 5 dB
Signal Amplitude
Ullage
Point 1
Point 2 Point 3
Point 4
6. Return to measuring mode and check that the transmitter detects the product
surface.