3 mounting and installation, 1 general installation instructions, Measuring range – VEGA VEGAPULS 51K…54K Profibus PA User Manual
Page 13: False echoes
VEGAPULS 51P … 54P
13
24890-EN-041227
Mounting and installation
Measuring range (operating range) and max. measuring distance
Note: Use of the sensors for applications with solids is limited.
full
Meas. range
max. meas. distance 20 m
3 Mounting and installation
3.1 General installation instructions
Measuring range
The reference plane for the measuring range
of the sensor is the lower edge of the flange
or the seal shoulder of the thread
(VEGAPULS 51 … 52). The measuring range
is 0 … 20 m. For measurements in surge or
bypass tubes (pipe antenna) the max. meas-
uring distance is reduced.
Keep in mind that in measuring environments
where the medium can reach the sensor
flange, buildup may form on the antenna and
later cause measurement errors.
Note: The series 50 sensors are suitable for
measurement of solids only under certain
conditions.
False echoes
Flat obstructions and struts cause strong
false echoes. They reflect the radar signal
with high energy density.
Interfering surfaces with rounded profiles
scatter the radar signals into the surrounding
space more diffusely and thus generate false
echoes with a lower energy density. Hence,
those reflections are less critical than those
from a flat surface.
Reference plane
empty
Profiles with flat interfering surfaces cause large
false signals
Round profiles diffuse radar signals
Cover smooth, flat surfaces with deflectors
If flat obstructions in the range of the radar
signals cannot be avoided, we recommend
diverting the interfering signals with a deflec-
tor. The deflector prevents the interfering
signals from being directly received by the
radar sensor. The scattered signals are then
so low-energy and diffuse that they can be
filtered out by the sensor.
4 m
16 m
max.
max.
max.
max. filling