YSI IFL 700 IQ - Manual (Page 33)

IFL 70x IQ What to do if...
6 - 3 ba76129e01 10/2012
Number and position of
the echoes changing
often
Intensity of the existing
echoes changing
Cause Remedy
Small temporary interfering
echoes
(e.g. sludge flakes sinking slowly)
– Check Echo selection (Top-
most echo or Strongest
echo)
– A higher value for the Mini-
mum intensity filter ignores
echoes from small, slowly
sinking sludge fields.
New sludge blankets developing
(e.g. a new sludge blanket devel-
oping on top of an old, concen-
trated sludge blanket).
– Check Echo selection (Top-
most echo or Strongest
echo)
– Follow echo
(change setting to Yes)
– Set the Evaluation range to
the range expected for the
sludge level
Cause Remedy
Temporary effect of air bubbles or
thread algae – Select a measurement loca-
tion that has permanently
few air bubbles.
– Remove any thread algae
from the sensor and its envi-
ronment
– Clean the sensor
Check the wiper
– Check Echo selection (Top-
most echo or Strongest
echo)
– Follow echo
(change setting to Yes)
– Set the Evaluation range to
the range expected for the
sludge level
The sludge blanket level is very
high, or the sedimentation behav-
ior is insufficient Check and adjust the process