3 General principles
FLUXUS G801 3.1 Measurement principle
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UMFLUXUS_G801V1-0EN, 2020-06-26
Fig. 3.1: Sound path of the signal in the flow direction
c – sound speed
1 – transducer (emitter)
2 – transducer (receiver)
3 – pipe wall
Fig. 3.2: Sound path of the signal against the flow direction
c – sound speed
1 – transducer (emitter)
2 – transducer (receiver)
3 – pipe wall
Fig. 3.3: Transit time difference Δt
1 – signal in the flow direction
2 – signal against the flow direction
c
β
β
α
γ
c
γ
3
21
c
α
c
α
reduction of the
sound path
flow direction of the fluid
sound path
with flow
sound path
without flow
c
β
flow direction of the fluid
sound path
with flow
sound path
without flow
β
α
γ
c
γ
increase of the
sound path
3
12
c
α
c
α
1 2
Δt