In a message dated 30/01/2006, JDarwin@............. writes:

Anyone  know of a simple... quick... force gauge or force transducer...
20 - 30  grams max with a resolution of .1 gram.   that I could make or  buy?

I'm working on a wind tunnel for my grandson's science fair  project and 
we need a way to measure the lift and drag.
I  can  measure lift with a beam balance scale..

Oh... and did I say  cheap?



Hi Jan,
 
    You can buy 1 mm thick sheets of a rubbery  like material called QTC - 
Quantum Tunneling Composite. You sandwich it between  two metal plates and 
measure the resistance between them. With zero force you  have a near insulator. As 
the force increases, the electrical resistance drops.  This is a cheap way of 
making a force transducer.
 
    Regards,
 
    Chris Chapman






In a message dated 30/01/2006, JDarwin@............. writes:
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  know of a simple... quick... force gauge or force transducer...
20 - 30=
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  grams max with a resolution of .1 gram.   that I could make or=20
  buy?

I'm working on a wind tunnel for my grandson's science fair=20
  project and 
we need a way to measure the lift and drag.
I  can=
=20
  measure lift with a beam balance scale..

Oh... and did I say=20
  cheap?


Hi Jan,
 
    You can buy 1 mm thick sheets of a rubbery=
=20
like material called QTC - Quantum Tunneling Composite. You sandwich it betw=
een=20
two metal plates and measure the resistance between them. With zero force yo=
u=20
have a near insulator. As the force increases, the electrical resistance dro=
ps.=20
This is a cheap way of making a force transducer.
 
    Regards,
 
    Chris Chapman