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Quantum Tunneling Composite

  1. Dec 30, 2014 #1
    Is it possible to build a fast, accurate scale using QTC? If so, could someone explain the basics or point me toward a good resource? Thanks!
     
  2. jcsd
  3. Dec 31, 2014 #2

    Baluncore

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    What do you mean by “scale”? Are you measuring a force, such as weighing a mass?
    Accuracy usually requires a linear sensor, QTCs are exponential. I guess they will also be sensitive to temperature.
     
  4. Dec 31, 2014 #3
    Sorry - yes, weighing a mass. I read that the QTC output is exponential although a relatively simple formula? Temp would be stable/indoors. Ideally Needs to be accurate to within ~1%. Seems to be VERY little info out there on this material.

    I ask primarily because I read that this stuff can take up to 40 seconds to produce a final weight measurement and can produce variable/inaccurate readings. However given the importance of precision in some of qtc's current applications this seems unlikely..
     
  5. Dec 31, 2014 #4

    Baluncore

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    What current applications are you referring to that require precision?

    A composite will have typical bulk properties. If the force is applied to the material in a slightly different way then you can expect different results. To be accurate, QTC sensors would need to be very small and mounted within a fixed geometry structure.

    As I see it, QTCs are being used with an AC coupled front-end to extract dynamic signals that can then be fed into a signal processor.

    Before designing a new product that employs QTCs, you should specify your requirements and consider off-the-shelf earlier technologies that have been proven reliable. Focusing on an unproven new technology is a distraction, it will delay product launch and lead to failure in the market place. Dreams are ten a penny.
     
  6. Jan 3, 2015 #5
    Depends on the nature of your product. Some people make their living making scales and others make a living selling sensors to the scale makers. Being a "me too" translates too poor margins and filled marketplaces. This country didn't make it to the moon by shooting down ideas, but it's doubtful that it will make it back while waiting for others to solve each problem.
     
  7. Jan 3, 2015 #6

    Baluncore

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    It is clear that FinanclEngr wants to build the scales.

    There is a way to make an accurate scale using QTC. You build a mechanical oscillator with a spring and the mass to be measured. Then use a QTC sensor to measure the forces in the system as it oscillates, digitise that signal then extract the frequency of oscillation, from which the mass can be computed, Freq α Sqrt(1/mass). That should eliminate the majority of amplitude and phase effects from the measurement.
     
  8. Jan 3, 2015 #7
    Do you know how labor and machine intensive it is to build a load cell? If this man has conceived a notion to produce the replacement device in a more producible fashion, then why not allow him the dignity of at least working through the thought experiment?
     
  9. Jan 3, 2015 #8

    Baluncore

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    Yes, I designed and built load cells in the 1980s.
     
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