Endress+Hauser Micropilot FMR56 - Expert → Sensor → Echo Tracking

Micropilot FMR50/FMR51/FMR52/FMR53/FMR54/FMR56/FMR57 FOUNDATION Fieldbus The "Expert" menu
Endress+Hauser 109
3.2.15 Expert → Sensor → Echo tracking
Basic principles of the echo tracking
Three types of echo evaluation can be selected in the Evaluation mode parameter:
Evaluation mode "History off"
The envelope curve is evaluated statically. First echo criteria are taken into consideration
(see the Expert → Sensor → First echo factor submenu).
Evaluation mode "Short time history"
The static envelope curve evalauation is taken as a starting point.
The position of the individual echoes is tracked. The track contains the position, the
velocity, the relative and the absolute echo amplitude. Normally the strongest echo within
a search window is selected and allocated to the track.
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aA
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 18 Definition of a track: In a new envelope curve, the echo is searched for in a window of width "a" centered
around the echo position in the previous envelope curve. The change of the echo position in the course of
time defines the track.
Evaluation mode "Long time history" (only available for level measurements)
A so-called tank history is used for the determination of the level and a consistency check
of the echoes. For a given tank with a given medium, the positions of the level, interface,
multiple and end-of-probe or tank bottom echoes are in a defined relation to each other.
This relationship is recorded during the operation of the device and stored in the tank
history. On the basis of this tank history, echoes can be reliably allocated, even if one echo
is lost temporarily or if the device was switched off for a while.