Patent ID: 7296475

Claim:
A displacement instrument for determining a modulus of a material, comprising: a vertically oriented casing having an interior therein; a horizontally oriented support member in said interior of said casing divides said casing into an upper chamber and a lower chamber; said support member having a top surface and a bottom surface; a bore hole extends vertically down through said support member from said top surface to said bottom surface; a vertically oriented air cylinder having a top end, a bottom end, and a piston in said air cylinder that can travel reciprocally up and down in said air cylinder; said bottom end of said air cylinder having an air outlet port; said bottom end of said air cylinder being connected to said top surface of said support member with said air outlet port being in communication with said bore hole of said support member; a vertically oriented piston rod has a bottom end connected to said top end of said piston; said piston rod having a top end that extends upwardly through said top end of said air cylinder; a mass is located in said upper chamber and it has a bottom surface; a first connector for connecting said top end of said piston rod to said bottom surface of said mass; an air pressure transducer located in said lower chamber; said air pressure transducer having an air inlet port; a second connector for connecting said air inlet port of said air pressure transducer to said bottom end of said bore hole in said support member thereby forming an air pressure chamber that extends from said bottom end of said air cylinder into said air pressure transducer; an electrical circuit connected to said air pressure transducer capable of creating an electrical voltage output signal in response to said piston in said air cylinder being driven downwardly by said mass that compresses the air in said air pressure chamber; and a third connector capable of delivering the output signal to a computer adapted to determine the modulus of the material.