KROHNE BM 70 M - Manual (Page 67)

BM 70 M 67
Group A: Signal output
No.
Fault / Symptom Cause Corrective action
DA6 When the empty tank
is being filled, the
measured value
initially stays at
"zero" and then, at
20...100 cm level,
suddenly skips to the
correct value. The BM 70 M is receiving
an additional signal from the
tank bottom. Activate "tank bottom tracking
system",
see Sect. 8.6.15 (Fct. 3.5.7 -
3.5.8)
DA7 Display and signal
output do not
respond to changes
in level. Digital input is activated,
marker 6 is ON,
measurement is suspended
(frozen). Deactivate the digital input, see
Sect. 4.8.
Device is within block
distance detection range,
marker 6
 is ON;
level too high or antenna
contaminated.
Reduce level and/or clean
antenna, or deactivate Fct. 3.5.6
BD-DETECT (see Sect. 8.6.14)
or reduce size of Fct. 3.1.2
BLOCKDIST.
(see Sect. 8.6.3).
Foaming in vessel,
inadequate reflectivity of the
WDQNSURGXFW0
R
too small;
additionally, markers 1+3
may be ON.
On tall storage tanks, mount the
BM 70 M farther away from the
tank wall. Select distance as
recommended in Sect. 6.1.2.
DA8 Display and signal
output indicate "zero"
measured value,
marker 5
 is ON.
Tank with dished bottom:
tank is more than 20% full,
the BM 70 M is mistakenly
located in the "tank bottom
detection" range. Drain tank or switch the BM 70
M off for a short while. If
unsuccessful, please consult
KROHNE Service.
DA9 Display and signal
output indicate max.
level but tank is
empty. Tank with dished bottom:
the
BM 70 M has stored an
incorrect or incomplete
empty spectrum. Record new empty tank
spectrum, see Sect. 8.6.12 (Fct.
3.5.2), or enlarge block distance
(Fct. 3.1.2) as described in Sect.
8.6.3.
Group DA: Display and signal output
No.
Fault / Symptom Cause Corrective action
DA10 Display and signal
output frequently
indicate the
maximum level. Excessive amounts of
vapour, condensate or dust
in the tank, or heavy
contamination (deposits
thicker than approx. 3 - 7
mm or 0.1" - 0.3") on the
antenna. Clean antenna (install cleaning
device if necessary). If
unsuccessful, enlarge
BLOCKDIST. under Fct. 3.1.2
(see Sect. 8.6.3) or deactivate
Fct. 3.5.6 BD-DETECT
(see Sect.8.6.14).
Antenna cleaning
operations cause strong
reflections.
Activate digital input during
cleaning
(marker 6

is ON),
measurement suspended
(frozen), see Sect. 4.8.