LESS THAN ¼” (6 mm)
Figure 22: Paper template alignment
Line Marking
Circumference
Edge of
Paper
Fold
Pipe Circumference
Crease
(Center of Pipe)
Transducer
Spacing
Figure 23: Bisecting the pipe circumference
5 . For DTTR, DTTN, DTTL and DTTH transducers, place a single bead of
couplant, approximately 1/2 inch (12 mm) thick, on the flat face of the
transducer . See
. Generally, a silicone-based grease is used
as an acoustic couplant, but any good quality grease-like substance
that is rated to not flow at the operating temperature of the pipe is
acceptable .
6 . Place the upstream transducer in position and secure with a stainless
steel strap or other fastening device . Straps should be placed in the
arched groove on the end of the transducer . A screw is provided to help
hold the transducer onto the strap . Verify that the transducer is true to
the pipe, adjust as necessary . Tighten transducer strap securely . Larger
pipes may require more than one strap to reach the circumference of
the pipe .
TOP VIEW
OF PIPE
Figure 24: Z-Mount transducer placement
7 . Place the downstream transducer on the pipe at the calculated transducer spacing . See
. Using firm hand
pressure, slowly move the transducer both towards and away from the upstream transducer while observing signal
strength . Clamp the transducer at the position where the highest signal strength is observed . A signal strength percentage
between 10…98 is acceptable .
The factory default signal strength setting is 10% . However, there are many application-specific conditions that may
prevent the signal strength from attaining this level . A minimum signal strength of 5% is acceptable as long as this signal
level is maintained under all flow conditions .
On certain pipes, a slight twist to the transducer may cause signal strength to rise to acceptable levels . Certain pipe and
liquid characteristics may cause signal strength to rise to greater than 98 . The problem with operating this flow meter with
very high signal strength is that the signals may saturate the input amplifiers and cause erratic readings . Strategies for
lowering signal strength would be changing the transducer mounting method to the next longest transmission path . For
example, if there is excessive signal strength and the transducers are mounted in a
Z
-Mount, try changing to
V
-Mount or
W
-Mount . Finally, you can also move one transducer slightly off-line with the other transducer to lower signal strength .
8 . Secure the transducer with a stainless steel strap or other fastener .
Transducer Installation
Page 25
November 2016
HYB-UM-00090-EN-04
