10
8.2.2 Recommended value of depth direction measuring point within flow range(Table 2):
Table 2
Depth
（
m
）
Point
number
＜
1
3-4
1-3
4-6
4-7
5-8
＞
7
6-10
8.2.3 Multi-point average velocity method classical formula:
Mode
Measuring Point Position
Average Velocity
1-poin
t
0.6*h
V
m
=V
0.6
2-poin
t
0.2/0.8h
V
m
=
(
V
0.2+
V
0.8)
/2
3-poin
t
0.2/0.6/0.8h
V
m
=0.25(V
0.2
+2 V
0.6
+ V
0.8
)
4-poin
t
0.2/0.4/0.7/0.9h
V
m
=0.25(V
0.2
+ V
0.4
+ V
0.7
+ V
0.9
)
5-poin
t
Close to surface/0.2/0.6/0.8h/Riverbed
V
m
=0.1(V
0
+3V
0.2
+ 3V
0.4
+ 2V
0.8
+ V
S
)
6-poin
t
Close to
surface/0.2/0.4/0.7/0.9h/Riverbed
V
m
=0.1(V
0
+2V
0.2
+ 2V
0.4
+
2V
0.7+
2V
0.9
+ V
S
)
Note: The sensor must be flooded about 10cm when close to surface. Please according to
the actual need to choose.
8.2.4 Flow calculation
8.2.4.1 Flow calculation between measuring point line
8.2.4.2 Line flow calculation
