Nivus NivuFlow 750, Инструкция по эксплуатации

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Instruction Manual
NivuFlow Mobile 750
page 28 NFM 750 - rev. 03 / 27.05.2020
Fig. 21-2 Situation at second signal detection
The DSP checks both received reflection patterns for similarities using the cross correlation
method. All existing signal differences (caused by new or rotated particles) are rejected so
that two similar but temporarily offset signal patterns are left for velocity evaluation.
Depending on the flow levels both patterns are subdivided into 16 measurement windows.
Fig. 21-3 Echo signal images and evaluation
Based on the beam angle, the interval between both transmitted signals and the shift of the
signal pattern therefore in each single measurement window the flow velocity can be deter-
mined.
It mathematically strings the single flow velocities together which results in the flow profile of
the acoustic path.
This velocity profile is indicated directly on the display of the NivuFlow.
Fig. 21-4 Determined flow profile
If a sufficient calming section is available on the measurement place it is possible to compute
a 3-dimensional flow distribution (see Fig. 21-4). The result is based on the geometric data of
the flume and the velocity distribution.