Emerson Rosemount 5708, Справочное руководство

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112
Reference Manual
00809-0100-4570, Rev DA
Operation
November 2017
Operation
7.5.7 False Echo Mapping
Selecting this option allows performing False Echo Mapping on any of the beams to ignore false echoes
inside the vessel cause by internal object or interferences.
To open the False Echo Mapping option:
On the Device menu, select Device False Echo Mapping… .
Figure 7-73. False Echo Mapping
Device – select the device to perform False Echo Mapping function on.
Beams’ check-boxes – it is possible to perform any of the actions on all beams or any combination of the
beams.
Action Type:

Reset User and Auto False Echoes – delete all false echoes done by the Auto False Echo algorithm and
in the False Echoes Mapping created by the user.

Reset User False Echoes – delete all false mapping done by the user.

Reset Auto False Echoes – delete all false echoes done by the Auto False Echo algorithm.

Scan – automatic False Echo Mapping between the set ranges From/To distance.

Manual Scan – set a constant level at the defined threshold between the From and To distances.

Start Scanning (or Reset Mapping ) – select to start the calculation.
Suggested steps for Echo Curve Analysis and False Echo Mapping
1. Measure the distance from the device to the material below it with a second reference, such as a tape
measure equipped with a weight on the end, or a laser. Record the distance measurement for further
reference.
2. Perform the Echo Curve Analysis, see “Echo curve analysis” on page 62 . Once completed, the Echo
Curve window opens (same as in “Viewing Echo Curve Analysis” on page 110 ).
3. Determine if the location of the echoes (vertical lines) are close to the manual measurement taken
earlier. Note that the Rosemount 5708 is taking measurements of multiple points and may not match
up with the manual measurement exactly.
4. Figure 7-74 is an example of the representation of false echo in the Echo Curve window. A manual
measurement and reads 2.5 m. When comparing to the Echo Curve Analysis, echoes appear in the
first 1m. These are clearly false echoes and will need to be mapped out.