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APPENDICES
A1 Testing the Flow Profile for Symmetry
If there is any doubt as to the symmetry of the flow profile (see
Section 3.2), a Partial Velocity Traverse should be carried out.
This procedure involves comparing the value of velocity at two
points at equal distances from the centre line.
It is normal to compare the flow velocities at insertion depths of
1
⁄
and
7
⁄
of the pipe diameter as these points are always on the
8
8
'knee' of the profile.
A1.1 Partial Velocity Traverse
Determine the internal diameter D of the pipe, in millimetres,
by the most accurate method available. If the AquaProbe
insertion length is greater than the internal diameter of the
pipe, proceed with the Single Entry Point Method detailed in
Section A1.2. If the AquaProbe insertion length is less than the
internal diameter of the pipe, proceed with the Dual Entry
Point Method detailed in Section A1.3.
A1.2 Single Entry Point Method
a) Insert the probe to a depth of
3.14 on page 9.
Note. Due to software configuration, all calculations
are in metric units. Therefore if using an imperial pipe, the
diameter
be converted into millimetres (1in =
MUST
25.4mm) i.e. a 36in pipe = 914mm.
b) Calculate the insertion factor F
c) Refer to the AquaProbe Transmitter Configuration Manual
and enter a Blockage Factor (BL) of value equal to F
d) Record the flow velocity reading.
e) Insert the probe to a depth of
f) Calculate the insertion factor F
g) Refer to the AquaProbe Transmitter Configuration Manual
and enter a Blockage Factor (BL) of value equal to F
h) Record the flow velocity reading.
i) Calculate the ratio of the two values recorded.
18
1
⁄
the pipe diameter – see Fig.
8
12.09
1.3042
=
.
1 +
+
√D
i
D
.
i
7
⁄
the pipe diameter.
8
12.09
1.3042
=
1 +
-
i
√D
D
.
i
If the ratio is between 0.95 and 1.05 the flow profile is
acceptable and the procedure detailed in section 5.2 can be
used. If outside this ratio the AquaProbe should be resited for
optimum accuracy.
A1.3 Dual Entry Point Method
Refer to Section 3.5 and fit a second mounting boss directly
opposite the one already fitted.
Note. Due to software configuration, all calculations
are in metric units. Therefore if using an imperial pipe, the
diameter
be converted into millimetres (1in =
MUST
25.4mm) i.e. a 36in pipe = 914mm.
a) Insert the probe to a depth of
the original mounting boss.
b) Calculate the insertion factor F
c) Refer to the AquaProbe Transmitter Configuration Manual
and enter a Blockage Factor (BL) of value equal to F
d) Record the flow velocity reading.
e) Insert the probe to a depth of
the second mounting boss.
f) Record the flow velocity reading.
g) Calculate the ratio of the two values recorded.
If the ratio is between 0.95 and 1.05 the flow profile is
acceptable and the procedure detailed in Section 5.2 can be
used. If outside this ratio the AquaProbe should be resited for
optimum accuracy.
.
1
⁄
the pipe diameter through
8
12.09
1.3042
=
.
1 +
+
√D
i
D
.
i
1
⁄
the pipe diameter through
8
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