Hach-Lange SONATAX sc - Manual (Page 19)

19
Installation
Example 1: Pre-thickener with clear separation layer, but
sporadically empty.
The image shows a thickener with a clear profile. The signals above
the sludge level caused by turbid water do not disrupt the
measurement.
The same thickener is empty in this image. The threshold now
adjusts itself automatically to the signals of the turbid water. The
recorded measurement value at 0.63 m is incorrect.
Recommended measure:
Increase the adjustment of the ADV. SETTINGS > LL THRESH.
AUTO setting from 0.3 to 1.0.
Note: LL THRESH. AUTO gives the smallest possible value that the
threshold can accept.
The image shows the empty thickener after the adjustment. The
result 3.18 m is correct.
Example 2: Application with clear separation layer, but weak
signal.
Very low to absolutely no interference signals through turbid water
above the separation layer. Strength of the echo 0.61 is above the
LL THRESH. AUTO (pre-setting 0.3) and leads to correct
measurement value 2.28 m.