NUS-4
NUS-4 K05/0216
Seite 5
5. Operating Principle
The sensor emits an ultrasonic pulse train and receives the echoes reflected. The
intelligent electronic device processes the received signal by selecting the echo
reflected by the surface and calculates from the time of flight the distance between
the sensor and the surface. A Norm signal output is available for remote transfer
whereas a relay contact is available for monitoring purpose.
A narrow beam angle ensures a reliable measurement in narrow silos with uneven
side walls as well as in process tanks with various protruding objects. Furthermore,
as a result of the narrow beam angle - the emitted ultrasonic signals have an
outstanding focusing - deep penetration through gases, vapour and foam is
ensured.
6. Mechanical connection
6.1 Block distance
Due to signal characteristics of the sensor, there is an area directly below the
sensor, where no pulses can be received (Dead Zone).
The so called Block distance (minimum measuring distance) is very important for
error free functioning of the level meter. It determines the minimal distance
between the sensor and maximum level. This distance can be extended by
programming in order to avoid disturbing effects of possible disturbing echoes
coming from fixed objects (Close-end Blocking).
Mount the sensor high enough that even with maximum filling of the container,
the block distance is not violated. Violation of the block distance may lead to
device-malfunction.
Model Block
distance
NUS-4x04
0,20 m
NUS-4x06
0,25 m
NUS-4x08
0,35 m
NUS-4x10
0,35 m
NUS-4x15
0,45 m
NUS-4x25
0,60 m
