Siemens SITRANS FUH1010 Product Instruction Manual page 30

Flow Calibration Factor
Normally, the flow stream is parallel to the axis of the pipe. On this basis, the calibration
factor of a clamp-on ultrasonic flow meter is proportional to the cosine of the beam angle
relative to the pipe axis. However, this reveals that if the angle of flow stream is not in line
with the pipe axis, the flow calibration factor could be compromised. This most often occurs
when the sensor mounting location is within close proximity of a bend or other pipe
obstruction.
①
②
③
④
Reflect mounting automatically corrects for non-axial flow or cross flow since the 2 vectors in
a reflected beam are affected in opposite directions, such that the individual cross flow errors
cancel each other.
FUH1010 IP65 NEMA 4X Precision Volume
Operating Instructions, 01/2013, A5E32122003-AA
Upstream Sensor
Downstream Sensor
Flow Direction
WideBeam transmissions exchanged between the Upstream and Downstream sensors
Description
3.4 Theory of Operation
29