General information – Hach-Lange SONATAX sc User Manual
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General information
) ((2)
). The graphic display (for example sc1000)
shows the profile in the measurement operation as a graphic ((1)
).
The example shows a typical profile curve of a sludge level
measurement. The Y axis in this graphic reaches from the floor
(which can be set in the probe menu SENSOR SETUP >
CALIBRATE >
) up to the water surface.
The profile strength is given on the X axis. The profile increases at
a sludge level. If the solid content below the sludge level remains
constant, the profile strength decreases again due to the absorption
of the ultrasound in the sludge. At the very bottom, the echo of the
floor is normally detected.
The vertical line represents the threshold. The sludge level is
detected by the SONATAX sc at the point at which the profile
exceeds this threshold for the first time viewed from above
(analogous to the abovementioned definition of the sludge level). In
the graphic, the detected sludge level is identified by a mark on the
Y axis.
The threshold is set automatically on the SONATAX sc (setting:
THRESHOLD AUTO = xy % in the probe menu SENSOR SETUP >
CALIBRATE > ADV.SETTINGS >
). The automatic threshold function searches for the
maximum in the detected profile. Through an exact setting of the
tank depth, a faulty measurement due to the echo of the floor is
ruled out.
The background is that the echo signal of the floor in most tanks is
the strongest in the profile. With a correct setting of the tank depth,
the floor signal is not considered by the automatic threshold
function during the determination of the sludge level.
For more information on the correct determination of the tank
depth, refer to section
.
Figure 3 Profile as graphic and list