Dakota Ultrasonics MX-5 - Manual (Page 33)

MX-5 Ultrasonic Thickness Gauge
29
APPENDIX B
Application Notes
• Measuring pipe and tubing
When measuring a piece of pipe to determine the thickness of the pipe
wall, orientation of the transducers is important. If the diameter of the pipe
is larger than approximately 4 inches, measurements should be made with
the transducer oriented so that the gap in the wearface is perpendicular (at
right angle) to the long axis of the pipe. For smaller pipe diameters, two
measurements should be performed, one with the wearface gap
perpendicular, another with the gap parallel to the long axis of the pipe.
The smaller of the two displayed values should then be taken as the
thickness at that point.
Perpendicular Parallel
• Measuring hot surfaces
The velocity of sound through a substance is dependant upon its
temperature. As materials heat up, the velocity of sound through them
decreases. In most applications with surface temperatures less than about
200
°
F (100
°
C), no special procedures must be observed. At temperatures