Coating a piezoelectric transducer...

Discussion in 'The Projects Forum' started by Externet, Feb 12, 2016.

  1. Externet

    Thread Starter AAC Fanatic!

    Nov 29, 2005
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  2. Bernard

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    Aug 7, 2008
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    I would use several coats of clear Krylon spray, or as I still have a little left. Permalac, spray lacquer which
    " We " have used for exterior metal artwork for several years.
    I read & thought I had hard copy of how to make an under water microphone, but my search turned up zilch.Will try to recall parts if desired.
     
  3. RichardO

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    May 4, 2013
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    Since the body is mostly water... In my long ago days in diagnostic ultrasound I saw transducers with epoxy, urethane and silicone rubber on the face that contacted the skin.

    Also, don't forget the backing material. If the transducer uses a pulse to get an echo then the backing must damp the transducer so it does not ring for too long a period.


    Note that these are tidbits I picked up in passing and may or may not have value. ;)
     
  4. Externet

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    Thanks.
    My concern is mostly oriented to discern if a soft or a hard coating, to avoid impairing/blocking/absorbing its vibration response. Seems so far I will go with a thin layer of silicone. Will see...
     
  5. Alec_t

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    Sep 17, 2013
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    To maximise transmission and minimise spurious reflection at interfaces the acoustic impedance of the coating should be intermediate between that of the transducer and that of water. Tables of acoustic impedance for various materials can be found here.
     
  6. Bernard

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    Might try Google- DIY Hydrophone.
     
  7. hp1729

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    Nov 23, 2015
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    How deep under water are we talking about? Salt water or fresh water? Toilet water?
     
  8. hp1729

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    Nov 23, 2015
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    Deep water? Maybe something like this would be better?
     
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