14
TRANSDUCER MOUNTING POSITIONS
Mounting Ultrasonic Transducers
The pipe must always be filled completely
at the mounting positions of the ultrasonic
transducers. It is not possible to take
measurements on partially filled pipe.
CAUTION
The ultrasonic transducer can be operated in any mount-
ing position. However, conforming with the mounting
positions shown below is mandatory. The drawing shows
the side view of the piping.
Mounting Ultrasonic Transducers On
Horizontal Pipe
FIGURE 23:
Preferable mounting positions for ultrasonic
transducers (1)
On horizontal piping, mount the transducer with an offset
of about +/-45% to the horizontal plane. Otherwise, there
is a risk of the accumulation of bubbles in the upper sec
-
tion and sedimentation in the lower section of the pipe.
FIGURE 24:
Preferred mounting positions for ultrasonic
transducers (2)
UFM uses the cross section of the pipe to calculate
the flow. The cross section is calculated from the inner
diameter setup (user setting). If there is sedimentation
in the pipe, which decreases the real inner diameter, a
small amount of uncertainty may result. The same hap-
pens when the inner diameter is not known/estimated.
π
α
⋅
⋅
⋅
⋅
−
=
4
cos
2
2
1
)
1
2
(
2
D
T
T
T
T
L
Q
i
To measure pipes with unknown wall thicknesses
a wall thickness gauge is avaiable from GPI. Ask
GPI Customer Service Representative for more
information or visit www.GPImeters.net.
Ultrasonic Transducers On Non-Planar
Surface
Never mount the transducers on non-planar surfaces such
as welding seams or deformations. Always try to remove
thick and uneven protective paint coating from the piping
area where the ultrasonic transducers will be mounted.
Mounting Ultrasonic Transducers
Following are the options for mounting the ultrasonic trans-
ducers. The V-mode is standard for most applications.
V-Mode
FIGURE 25:
Mounting of transducers in V-mode
Transducer 1 Transducer 2
In the V-mode, both ultrasonic transducers are mounted
onto the same side of the pipe. This mode is the standard
for small and medium pipe dimensions. The ultrasonic
signals are reflected from the pipe wall.