KROHNE BM 70 A_P EN - Manual (Page 56)

Installation and operating instructions BM 70 A/P Page: 56 11/00
8.8 Pointers and error messages during measurement
8.8.1 Different kinds of messages
a) Pointers (operating conditions) during measurement provided by 6 markers
6
in the 3rd (bottom) line of
the display, see Sect. 8.8.2.
b) Application errors, indicating an application error condition in which no valid measured values are
currently established. By changing the tank conditions (e.g. filling) this error can usually be remedied, see
"Error list" in Sect. 8.8.3.
c) Minor errors, indicating the failure of functions that usually do not affect measurement, see "Error List" in
Sect. 8.8.3.
d) Correctable errors, which can be remedied by operator action (manual) at the BM 70 A/P, or possibly by
KROHNE Service, see "Error List" in Sect. 8.8.3.
e) FATAL ERROR renders operation of the BM 70 A/P impossible; occurs only when the device is switched
on (powered) or after special test functions have been executed, when the self-test identifies an error in
the
electronics of the BM 70 A/P, see "Error List" in Sect. 8.8.3.
8.8.2 Pointers provided by 6 markers
6 6
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.