KROHNE BM 70 M - Manual (Page 62)

62 BM 70 M
8.8.2 Pointers provided by 6 markers during measurement
Marker Cause Explanation
1 No current
measured
value
The device is currently searching for a new measured value in which
the "measuring window" is opened. If the search for a plausible level
fails, "SIGNAL DOWN" appears in the Error List, see Sect. 8.8.3.
2 Signal too
strong
Mean of reflected microwaves is very high. Gain is automatically
stepped down. Brief showing of this marker, e.g. while tank is being
filled or drained, is insignificant. In conjunction with stilling wells, the
marker can also show for a longer time.
3 Poor
spectrum
Number of acceptable spectra is too low. Brief showing of this
marker has no significance. If permanently on, this may result in
uncertain (incorrect) measured values or the error message
"NO M.VALUE", see Sect. 8.8.3.
4 No measured
value as yet
Evaluable measured values not available after the device has been
started up. Measured value automatically set to the level of the tank
bottom. This marker disappears when the first valid measured value
is obtained.
5 Tank bottom In tanks with dished bottom, for example, the measuring signal can
"disappear" if measurements are carried out near the bottom (within
a range of 10% of the tank height, see Fct. 3.1.1, but minimum of 20
cm or 8" and maximum of 60 cm or 24"). The measured value is then
automatically set to the level of the tank bottom.
6 Measurement
frozen
The digital input is active (voltage at terminals 81,82) or the device is
in the range of the block distance detector (see Sect. 8.6.12).
Measurement is thus suspended (frozen); last measured values
present at the outputs and in the display.