Function And System Design; Measuring Principle - Endress+Hauser Levelflex FMP51 Technical Information

Measuring principle

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Function and system design

Basic principles
The Levelflex is a "downward-looking" measuring system that functions according to the ToF method
(ToF = Time of Flight). The distance from the reference point to the product surface is measured.
High-frequency pulses are injected to a probe and led along the probe. The pulses are reflected by
the product surface, received by the electronic evaluation unit and converted into level information.
This method is also known as TDR (Time Domain Reflectometry).
R
LN
 1 Parameters for level measurement with the guided radar
LN Probe length
D Distance
L Level
R Reference point of measurement
E Empty calibration (= zero)
F Full calibration (= span)
If, for rope probes, the DC value is less than 7, then measurement is not possible in the area of
the straining weight (0 to 250 mm (0 to 9.84 in) from end of probe; lower blocking distance).
D
E
L
Levelflex FMP51, FMP52, FMP54
20 mA
100%
F
4 mA
0%
Endress+Hauser
A0011360