Siemens OCM III Instruction Manual page 55

SIMPLE EXPONENTIAL DEVICES, P3 = 0
TYPICAL PARSHALL FLUME
C
2/3 C
plan
transducer *
0
head
side
front
For rated flows under free flow conditions, the head is measured at 2/3 the length of
the converging section upstream of the beginning of the throat section.
* The transducer must be above the maximum head by at least the
blanking value, P47.
7ML19985AB01 OCM III 56