Siemens SITRANS FUH1010 Product Instruction Manual page 28

Viscosity Compensation
Wide Beam technology is designed to utilize the resonant frequency of the pipe wall. It does
so by broadcasting signals with various frequencies with the aim of finding the frequency that
best matches the pipe wall. When found, the signal is transmitted into the flowing media with
the wall of the pipe acting as a waveguide. This method allows for a low transmit voltage of
approximately +/- 15 volts and produces a focused, coherent signal that covers a large axial
area. This Wide Beam measurement method proves valuable especially when measuring
liquid hydrocarbon and is also and applicable for a expansive range of pipeline, refinery and
terminal purposes such as line balance, interface detection, transmix metering, and liquid
loading and unloading.
Wide Beam flow meters match the resonance frequency of the pipe by sending out
numerous signals with varying frequencies so there is a greater chance that the signal will be
able to penetrate a highly viscous fluid. This decreases the likelihood of an attenuated signal
and improves the reliability of the flow readings.
Since viscosity contributes to flow measurement difficulties by changing from liquid to liquid,
it is easily affected by temperature and pressure; it impacts the ideal signal required to
penetrate a liquid, and it results in various flow profiles. To compensate for this, the resonant
frequency of the pipe wall is used and the ultrasonic signal is transmitted into the flowing
media with the wall of the pipe acting as a waveguide. This produces a very strong and
coherent signal that works in numerous upstream, midstream and downstream applications.
The Wide Beam technology generates a strong and coherent signal that enables
measurement over an extensive range of viscosities, Vs and temperatures. By using
viscosity compensation and Reynolds number tables assure reliable flow readings.
Flow Meter Types
The meter automatically conditions Installation Menu choices to suit the selected meter type.
The following paragraphs introduce the available flow meter types that include:
● Single-Path
● 2-Path
FUH1010 IP65 NEMA 4X Precision Volume
Operating Instructions, 01/2013, A5E32122003-AA
Description
3.4 Theory of Operation
27