Siemens sitrans LU01 - Manual (Page 98)

Page 92 SITRANS LU01 – INSTRUCTION MANUAL 7ML19985BE02
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When the dust settles (and the echo is regained) the reported level advances toward the
actual level. When the reported level reaches 25.55 m (5% of Span less than the high high
alarm trip point), the high high alarm goes off, restarting the infeed and filling the vessel
to 27.00 m.
Material Volume
To perform a volume conversion for the preceding example, we'll assume:
• the vessel is cylindrically shaped with a flat bottom.
• the vessel volume for Empty to 29.01 m (Span) is 1457 m3.
Volume Parameter Settings
Now in the RUN mode the Reading represents material volume in m 3 .
Example 2 - Space Measurement
This mode of operation is commonly used when remaining vessel capacity is of more
importance to the installation than the actual material level.
Space
For this example we'll assume the following:
• the vessel is a 3 ft diameter by 15 ft long cylinder (including the parabolic ends of 1.5
ft each).
• the maximum vessel filling rate is 1 ft per minute (slower at mid level).
• a mA output scaled from 4 mA at Full to 20 mA at Empty is required for PLC
operation.
• in the event of a measurement difficulty, failsafe operation is to be activated in 6
seconds.
• if the difficulty doesn't subside, the mA output must immediately assume 22.00 mA.
• an XCT-8 transducer is mounted in a standpipe so that the face is 18 in. above the
vessel top.
• a TS-3 temperature sensor is mounted in the vessel to monitor liquid temperature.
Number Description Instructions
P050 Tank Shape Enter "1" for vertical cylinder with flat bottom .
P051 Max Volume Enter "1457" for 1457 m 3 .
1.5ft
(P052)
12.00 ft
(P053)
3.00ft
(P007)
3.00ft
(P007)