[Acoustics] ADCP Head cracking

[Victor A Levesque]

Hello Nathan,

After looking at the photos, I have to ask...have you let the transducer 
faces be exposed to sun light on a regular basis? Do you regularly cover 
the  transducers with the yellow protective cap? How old is the unit, and 
what kind of water have you used it in?

The blue plastic looks a little bleached out. I'm not a urethane expert, 
but you may have sun damage. It sort of looks like there has been a 
"drying out" of the urethane. The urethane (or is it polyurethane?) faces 
are susceptible to sunlight damage (not sure what wavelength!). The RDI 
manual even notes that you should minimize the transducer face's exposure 
to sun light. If the crazing doesn't penetrate too deeply, you could 
probably continue to use the ADCP (not liable for damages if I'm wrong), 
but you may be looking at urethane replacement (if that's possible) at the 
end of your season.

Perhaps someone at RDI would be more qualified to comment.

Good luck and let us know what you find.

Victor Levesque

U.S. Geological Survey
Center for Coastal and Watershed Studies
Tampa, FL
813-975-8620 extension 167
FAX: 813-975-0839
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