ABB LST400 - V-Notch

LST400 | ULTRASONIC LEVEL TRANSMITTER | OI/LST400-EN REV. E
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Shown to the right is what LST400 will display on the above
application. The relay will drive the counter for every 1000 Lt/s
and 1m³ of flow. The analogue output should be approximately
14.39 mA. Relay 2 would set at above 1.64 ft / 0.50 m and reset
at below 1.61 ft / 0.49 m. TIP: Set the relay set and reset point
further apart to avoid the relays from chattering.
Flow: 932.17Lt/s
T: 00001513408 Lt
Head: 1.48ft.
mA Output: 14.39 mA
Instant: 2.46 ft.
Temperature: 20°C
Percentage: 64.95%
V-Notch
This is an example of a V-Notch application. The transducer is
mounted 6.56 ft / 2.00 m above the Notch in the V, this is the
Empty Distance. The Span is 4.92 ft / 1.50 m and the Blanking
Distance is 1.64 ft / 0.50 m. The transducer must be fitted 3 x
maximum head-height upstream. There is an external counter
connected to the relay counter. The water flow must not dam up
and cause a build-up behind the weir.
Note: The Empty Distance is to the bottom of the V-Notch and
not the bottom of the weir.
NOTICE
Set the relay set and reset point further apart to avoid the
relays from chattering.
Below is what LST400 will display on the above application. The
relay will drive the counter for every 1000 counts. The analogue
output should be approximately 9.82 mA. Relay 2 will set above
4.76 ft / 1.45 m and reset below 4.43 ft / 1.35 m.
Flow: 444.60Lt/s
T: 00001513408 Lt
Head: 3.28ft.
mA Output: 9.82mA
Instant: 3.28 ft.
Temperature: 20°C
Percentage: 36.38%
K 10
Security code 
Mode FLOW
Empty distance 
Span 
Blanking 
Rate of change 
Fail timer 
Fail safe HOLD
Flow units Lt/sec
Maximum flow 
Flow curve V-NOTCH
Setup relays YES
 Counter
 
 HI
 
 
Totaliser reset NO
Zero offset 