KROHNE BM 90 EN - Manual (Page 21)

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Pr. 31 Analogue Value Options (D=1)
Pr. 32 Analogue Datum (D=0.00)
Pr. 33 Analogue Span (D=100)
Pr. 34 Analogue Output Test (D=0)
Pr. 30 Analogue Output (D=1)
Enter 1 - 4-20mA )
2 - 20-4mA ) > related to span (Pr.4)
3 - 0-20mA ) or Pr.33
4 - 20-0mA )
5 - 4-20mA ) > will over-range 0-24mA
if normal span
6 - 0-20mA ) (Pr.4) is exceeded
The output represents different variables depending on
the application mode selected at Pr.1
Limits are defined by Pr.4
Pr. 1 Entry Application Output Proportional To
1.00 Liquid Level a) Liquid Level
b) Liquid volume if Pr.40 is used
2.00 Distance a) Target distance
b) Space volume if Pr.40 is used
3.00 Differential (DLD) Differential level. (The unit can differentiate between
positive and negative differentials. (See Pr.31)
4.00 Open Channel Meter (OCM) a) If Pr.31 = 1 output proportional to head
b) If Pr.31 = 2 output proportional to flow
NOTE: Refer to Pr.34 for output test.
In differential mode (Pr.1 = 3)
Enter 1 - difference of two levels
- Pr.4 represents maximum differential in levels
2 - upstream level
- Pr.4 represents the difference between
upstream empty distance Pr.3 and maximum
upstream level.
3 - downstream level
- Pr.4 represents the difference between
downstream empty distance Pr.3 and
maximum downstream level.
In OCM mode (Pr.1 = 4)
Enter 1 - for measured head (depth of liquid)
2 - for calculated flow
If an analogue output is required with a zero different
from the measurement zero (Pr.3) then an offset defined
as a percentage of the measurement span/flow/volume
etc., can be entered here.
If an analogue output is required with a span different to
that defined for the measurement (Pr.4) then an alterna-
tive value defined as a percentage of the measurement
span/flow/volume etc., can be entered here. A value of
zero is ignored.
This parameter can be used to examine the last analogue
output value set up by the instrument. Also any value in
the analogue output range can be entered for loading to
the current output, and can be measured at the output
terminals, to test the external analogue circuitry.
Pr. 37 Temperature Sensor Enable (D=1)
Pr. 38 Compensating Temperature (D=20 C)
Pr. 39 Temperature Probe test (D=0)
1 = No sensor attached
2 = Senor attached
If no probe is fitted the vessel temperature may b entered
here.
Displays the sensor resistance in K Ohms. Typically 9.5
at 20 C.
If value shows ’0.00’ after switching ’Off’ and ’On’ then
either no sensor is connected, or there is a short circuit or
open circuit in the system.