Endress+Hauser Prosonic S FMU90, Description, Page: 53 / 216

The "flow" menu
53
"backwater detection"
"ratio B"
Use this parameter to specify the upper limit for the ratio h
2
/h
1
.
If during the measurement the ratio exceeds this limit, the backwater alarm becomes active, i.e.:
• the warning W 00 692 appears
• the backwater alarm relay is de-energized
10)
• if the backwater level continues to rise, the flow (indicated on the display and registered by the
counters) is continuously reduced to 0.
L00-FMU90xxx-19-00-00-yy-035
!
Note!
The default setting is B = 0,8.
This is the optimum value for Venturi flumes. To ensure reliable measurement it should not be
exceeded.
"dirt detection"
"ratio D"
Use this parameter to specify the lower limit for the ratio h
2
/h
1
.
If during the measurement the ratio falls below this level, the dirt alarm becomes active, i.e.
• the warning W 00 693 appears
• the dirt alarm relay is de-energized
11)
.
⇒
backw. detection F1305
ratio B:
10) In the "relay/controls" menu, one of the relays can be defined to be the backwater alarm relay.
h2
h1
h2
h1
h2/h1 > B h2/h1 < B
⇒
dirt detection F1306
ratio D:
11) In the "relay/controls" menu, one of the relays can be defined to be the dirt alarm relay