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Thread: Which is better for an Ultrasound proof hat(.2-8.0kHz, 135-140dB) Polymethylmethacrylate or Polycarbonate, and how thick must the helmet be?

  1. #1 Which is better for an Ultrasound proof hat(.2-8.0kHz, 135-140dB) Polymethylmethacrylate or Polycarbonate, and how thick must the helmet be? 
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    Will a normal motorcycle helmet be sufficient to keep the Federal Aliens from balding me, or do I need to construct something myself? What about a hard hat?


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    Forum Professor astromark's Avatar
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    Protection from Ultra sound radiations are not a mater of ear protections or a crash helmet.. A vacuum chamber or other means of screening is required.. Ultra sound can rearrange molecular structures.. Just like a microwave..
    but that it does require a transmission medium.. air works, water is even better.
    A vacuum stops it dead. Led lined and double Glassing.. Polystyrene transmits it so the helmets do not work well..

    but what federal aliens are we talking of ?


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    Quote Originally Posted by astromark View Post
    Protection from Ultra sound radiations are not a mater of ear protections or a crash helmet.. A vacuum chamber or other means of screening is required.. Ultra sound can rearrange molecular structures.. Just like a microwave..
    but that it does require a transmission medium.. air works, water is even better.
    A vacuum stops it dead. Led lined and double Glassing.. Polystyrene transmits it so the helmets do not work well..

    but what federal aliens are we talking of ?
    You didn't answer my question. You didn't mention what type of screening. I also didn't say any type of helmet. I specifically said 100 percent polycarbonate. Actually I noticed my arm disrupts it, why? And what screening do you suggest?
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    Again, .2 to 8KHz is within the range of normal audible sound frequencies. It is not ultrasound. Hence earplugs will work, as will earmuffs.
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    Quote Originally Posted by billvon View Post
    Again, .2 to 8KHz is within the range of normal audible sound frequencies. It is not ultrasound. Hence earplugs will work, as will earmuffs.
    I already stated that was an error, over 20kHz. You didn't read what I wrote, and have made no attempt to answer what materials could provide shielding. My reading has stated polycarbonate, not all thermoplastic though have it's shielding properties just going off what I read.
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