KROHNE BM 90 EN - Manual (Page 25)

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Pr. 64 to Pr. 67 Unspecified
Pr. 68 Echo Processing Algorithm
Pr. 70 Echo Velocity
Pr. 69 Check Search (D=1)
Pr. 71 Correction Value (D=0.00)
Each system has two echo extraction techniques, which
are capable of determining the "true" echo for the majority
of applications where an echo is present.
For Level-Sonic BM90: (D=2)
Enter 1 = All vessel viewing. This technique con-
tinuously looks for echoes over the complete vessel. It is
suited to applications that have very rapid level changes
but it is more sensitive to parasitic echoes.
Enter 2 = Windows. This technique positions a nar-
row ’window’ around the target it is tracking to enable it to
ignore a large amount of spurious noise.
For Level-Sonic BM90E: (D=1)
Enter 1 = For solids applications. This technique
looks for the highest level within the transducer view.
Enter 2 = For liquids. This technique positions a
narrow ’window’ around the target it is tracking to enable
it to ignore a large amount of spurious noise.
Only available if Pr.68 is set to 2. It enables the instru-
ment to look outside its window at intervals to check that
there are no other relevant echoes within the transducers
view.
Enter 1 = Not used
2 = Included
Check search should be used where fill rates can some-
times be greater than that entered at Pr.6, or if the trans-
ducer is liable to be submerged.
(D=344.1 i.e. speed of sound in air at 20 C)
If operating through any medium other than air, enter the
velocity of sound through that medium in metres per
second.
2. It can be used to prevent loss-of-echo when
the target can go further away from the transdu-
cer than the desired span.
e.g. a) When a channel floor is lower than the
zero point of a "V" notch weir.
b) To set an elevated zero level in a ves
sel which is not normally completely
emptied.
Add the extra depth to Pr.3 and enter minus the extra
depth at Pr.71 in the units selected at Pr.2.
Pr.72 Parameter Display (D=0)
The system will display continually the value of:
Gain - by entering 67
Temperature - by entering 38
Analogue output - by entering 34.
It can be used only for commissioning as it will be lost on
power down. It cannot be used in OCM mode.
Displays the revision number of the software
(e.g. LA.14).
Pr. 74 Reset Counter
This count value gives the number of times that the sys-
tem has been powered down or reset since the last time
the counter was zeroed. It is useful for checking if the
power supply is erratic.
Pr. 73 Software revision number
Both negative and positive values can be input. This
value must be entered in the units selected at Pr.2.
This parameter has two uses:
1. It can be used to correct minor reading errors
on the display
Pr. 75 Digital Outputs (D=0)
To aid commissioning and the testing of external wiring, it
is possible to define the status of all five relays when in
’PROG’ mode.
Press ’DSP’ then:
Enter 0 - To de-energise all relays
A D D 1 - To energise relay 1
ADD 2 - To energise relay 2
ADD 4 - To energise relay 3
ADD 8 - To energise relay 4
ADD 16 - To energise relay 5
e.g. To energise relays 2 and 5 enter ’18’
The defined relay state will be maintained until over-writ-
ten or until ’PROG’ mode times out (6 minutes). The time
period can be extended by pressing a key during this
period to reset the time-out counter.