Dynasonics TFX Ultra Transit Time Flow Meters - Manual (Page 23)

½ in.
(12 mm)
Figure 12: Application of couplant
Transducer Positioning
1. Place the upstream transducer in position and secure with a mounting strap. 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 and adjust as necessary. Tighten the transducer strap securely.
2. Place the downstream transducer on the pipe at the calculated transducer spacing. See Figure 13 . Apply firm hand
pressure. If signal strength is greater than five, secure the transducer at this location. If the signal strength is not 5 or
greater, using firm hand pressure slowly move the transducer both towards and away from the upstream transducer while
observing signal strength.
Signal strength can be displayed on the flow meter’s display or on the main data screen in the software utility. See Part
five of this manual for details regarding the software utility. Clamp the transducer at the position where the highest
signal strength is observed. The factory default signal strength setting is five, however there are many application specific
conditions that may prevent the signal strength from attaining this level. Signal levels less than five will probably not be
acceptable for reliable readings.
OTE:
N Signal strength readings update only every few seconds, so it is advisable to move the transducer 1/8 inch, wait, see if
signal is increasing or decreasing and then repeat until the highest level is achieved.
3. If after adjustment of the transducers the signal strength does not rise to above five, then an alternate transducer
mounting method should be selected. If the mounting method was W-Mount, then re-configure the transmitter for
V-Mount, move the downstream transducer to the new spacing distance and repeat Step 4.
Transducer
Spacing
Figure 13: Transducer Positioning
OTE:
N
Mounting of high temperature transducers is similar to
mounting the DTTN/DTTL transducers. High temperature
installations require acoustic couplant that is rated not to “flow”
at the temperature that will be present on the pipe surface.
OTE:
N
As a rule, the DTTL should be used on pipes 24 inches and larger
and not used for application on a pipe smaller than 4 inches.
Consider application of the DTTL transducers on pipes smaller
than 24 inches if there are less quantifiable aspects such as –
sludge, tuberculation, scale, rubber liners, plastic liners, thick
mortar liners, gas bubbles, suspended solids, emulsions, and
smaller pipes that are perhaps partially buried where a V-Mount
is required or desired.
V-MOUNT AND W-MOUNT INSTALLATION
Page 23 March 2014