Dynasonics DXN Portable Ultrasonic Measurement System - Manual (Page 23)

Alignment
Marks
Figure 25: Transducer Alignment Marks
V-Mount and W-Mount Installation
Application of Couplant
For DTTN, DTTH and DTTL transducers, place a single bead of couplant, approximately 1/2" (12 mm) wide, on the flat face
of the transducer. See Figure 26 . Generally, a silicone-based grease is used as an acoustic couplant, but any grease-like
substance that is rated not to flow at the temperature that the pipe may operate at will be acceptable.
½”
(12 mm)
Figure 26: Application of Couplant
Installation & Operation Manual
Page 23 February 2013