
AquaProbe FEA100 / FEA200
Electromagnetic flowmeter – insertion-type flow sensors
6 Specification
26
OI/FEA100/200–EN Rev. D
Limits of Upstream Disturbance
Note.
This Table is an extract from ISO7145 (BS 1042): Section 2.2: 1982 and is reproduced with the permission of BSI.
Complete copies of the standard can be obtained by post from BSI Publications, Linford Wood, Milton Keynes, MK14
6LE.
On
Centre Line
On
Cent
re
L
ine
5
Diameters
See
Table Below
Type of Disturbance Upstream from
the Measuring Cross-Section
Minimum Upstream Straight Length*
For a measurement at the point of
mean axial velocity
For a measurement on the
axis of the conduit
90° Elbow or a T-bend
50
25
Several 90° Coplanar Bends
50
25
Several 90° Non-coplanar Bends
80
50
Total Angle Convergent 18 to 36°
30
10
Total Angle Divergent 14 to 28°
55
25
Fully Opened Butterfly Valve
45
25
Fully Opened Plug Valve
30
15
*Expressed in multiples of the diameter of the conduit.
Downstream from the measurement cross-section, the straight length must be at least equal to five duct diameters whatever the type of
disturbance.