Product description
FLOWSIC60 · Operating Instructions · 8014241/YTG9/V1-0/2016-02 · © SICK Engineering GmbH
15
Su
bj
ec
t t
o c
han
ge
w
ith
ou
t n
ot
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2.1.2
Determinig the gas velocity
Measuring path L is equal to the active measuring path, that is, the area through which the
gas flows. Given measuring path L, sound velocity c, and angle of inclination
α
between the
sound and flow direction, the sound transit time in the direction of the gas flow (forward
direction) when the signal is transmitted can be expressed as:
i.e. a relation in which, except for the two transit times measured, only the active
measuring path and the path angle exist as constants.
Valid against the flow is:
After the resolution to v:
v =
·
(
)
t
BA
=
t
AB
=
L
1 1
2 · cos
α
t
AB
t
BA
L
c - v · cos
α
L
c + v · cos
α
(2.1)
(2.3)
(2.2)