Dynasonics DXN Portable Ultrasonic Measurement System - Manual (Page 9)

PIPE PREPARATION AND TRANSDUCER MOUNTING
DTTN and DTTL Transit Time Transducers
1. During this procedure, observe the flowmeter’s signal quality value. This value is available on the DXN Display>Meters
where TT Quality is one of the parameters that can be shown. Signal quality value should be at least 10%.
2. The pipe surface where the transducers are to be mounted must be clean and dry. Remove scale, rust or loose paint
to ensure satisfactory acoustic conduction. Wire brushing the rough surfaces of pipes to smooth bare metal may also
be useful. Plastic pipes do not require preparation other than cleaning.
3. Apply a single 1/2" (12 mm) wide by approximately 1/8" thick bead of acoustic couplant grease to the upstream
transducer and secure it to the pipe with a mounting strap.
4. Apply acoustic couplant grease, as in step 3 above, to the downstream transducer and press it onto the pipe using
hand pressure at the calculated lineal distance.
5. Space the transducers according to the recommended values found during programming. Secure the transducers
with the mounting straps at these locations while making sure to use the alignment marks on the transducers for
proper spacing.
DTTSU Universal Small Pipe Transit Time Transducers
1. During this procedure, observe the flowmeter’s signal quality value. This value is available in Display>Meters where TT
Quality is one of the parameters that can be shown. Signal quality value should be at least 10%.
2. The pipe surface where the transducers are to be mounted must be clean and dry. Remove scale, rust or loose paint
to ensure satisfactory acoustic conduction. Wire brushing the rough surfaces of pipes to smooth bare metal may also
be useful. Plastic pipes do not require preparation other than cleaning.
3. Set the downstream transducer spacing to the value found on the Site>Transit.
4. Apply a single 1/2" (12 mm) wide by approximately 1/8" thick bead of acoustic couplant grease to the face of each
transducer and secure the unit to the pipe with attachment chains.
5. Tighten the two thumb screws located on the top of the unit evenly so that the acoustic coupling grease begins
to flow out from the edges of the transducer and from the gap between the transducer and the pipe. Do not
over tighten.
DT94 Doppler Transducers
1. In general, select a mounting location on the piping system with a minimum of 10 pipe diameters (10 ×
the pipe inside diameter) of straight pipe upstream and 5 straight diameters downstream. See Table 1 for
additional configurations.
2. The pipe surface, where the transducers are to be mounted, must be clean and dry. Remove scale, rust or loose paint
to ensure satisfactory acoustic conduction. Wire brushing the rough surfaces of pipes to smooth bare metal may also
be useful. Plastic pipes do not require preparation other than cleaning.
3. Apply a single 1/2" (12 mm) wide by approximately 1/8" thick bead of acoustic couplant grease to both transducers
and secure them to the pipe 180° apart using a mounting strap. Ensure that the transducer cable is pointing in the
downstream direction.
4. Record the value calculated and displayed as "Required Spacing" in the Site>Transit.
Installation & Operation Manual
Page 9 February 2013