FLOWCERT LITE (UL) INSTRUCTION MANUAL
48
Point of Measurement
The transducer must be above the
maximum head P704
by at least the
near
blanking distance P107
.
For
Suppressed/Contracted Rectangular
,
Trapezoidal
and
V-notch
, weirs,
the head is measured
upstream
at a minimum distance of
3 times
maximum head
from the weir plate to ensure the surface of the liquid is not
affected by turbulence or drawdown. (
See DRWG. 1
)
In the case of a
Venturi
flume the point of measurement should be
150 mm
upstream
from the beginning of the
converging section
and for a
Parshall
flume
2/3 the length of the converging section
upstream of the
throat
section. (
See DRWG 2 and 3
).
3 x Hmax
minimum
FLOW (q)
DRWG. 1
DRWG. 2
DRWG. 3
FLOW (q)
FLOW (q)
2/3 L
L
VENTURI FLUME
PARSHALL FLUME
