Hach-Lange SONATAX sc - Manual (Page 20)

20
Installation
Very low to absolutely no interference signals through turbid water
above the separation layer. Strength of the maximum echo <0.3.
Instead of the correct measurement value, only the tank floor is
found.
Increase the adjustment of the ADV. SETTINGS > LL THRESH.
AUTO setting from 0.3 to 0.1. The threshold 0.16 finds the correct
measurement value 2.25 m.
Example 3: Thickener or other application with very high sludge
concentration up to just under the water surface; echo is absorbed
in the uppermost sludge layer:
In this application, the floor signal is no longer detected due to the
high absorption of the ultrasonic signal. The shown measurement
value 0.73 is correct. No adjustment of the ADV. SETTINGS
necessary.
If the sludge increases so far that the sludge level is above the
measurement range (the measurement range begins from 0.2 m
beneath the sensor), it can occur that no sludge level is detected
(SENSOR MEASURE error message). In this case, the application
must be checked.