초록 ▼

A magnetic domain strain gage and method of digitally measuring strain or fatigue within a ferromagnetic material by measuring the time required for an increasing magnetizing force to cause magnetic domains to flip orientation in a ferromagnetic material as a function of strain or stress within the

A magnetic domain strain gage and method of digitally measuring strain or fatigue within a ferromagnetic material by measuring the time required for an increasing magnetizing force to cause magnetic domains to flip orientation in a ferromagnetic material as a function of strain or stress within the material. The magnetic domain\s maximum rate of flip is measured as a time differential by a high frequency digital oscillator which provides a digital signal indicative of the strain thereby providing increased compatibility with digital data acquisition systems and having a superior signal to noise ratio in comparison with present low signal level analog resistance strain gages.

대표청구항 ▼

A strain gage comprising: a ferromagnetic conductive element having a plurality of magnetic domains; conductors attached to opposite ends of said ferromagnetic conductive element adapted for connection to a means for generating an electric biasing current; means for initiating a changing magnetic fi

A strain gage comprising: a ferromagnetic conductive element having a plurality of magnetic domains; conductors attached to opposite ends of said ferromagnetic conductive element adapted for connection to a means for generating an electric biasing current; means for initiating a changing magnetic field proximate to one end of said ferromagnetic conductive element, said magnetic field reversing the magnetic orientation of a majority of said plurality of magnetic domains, said means for initiating adapted for connection to an external power source; means for producing a signal indicative of the reversing of said plurality of magnetic domains, said means proximate to said ferromagnetic conductive element, and carrier means carrying at least said conductive element for securely positioning at least said conductive element, and for allowing attachment to a substrate. A fatigue gage comprising: a ferromagnetic conductive element having a plurality of magnetic domains; conductors attached to opposite ends of said ferromagnetic conductive element adapted for connection to a means for generating an electric biasing current; means for initiating a varying magnetic field proximate to one end of said ferromagnetic conductive element, said varying magnetic field causing the reversal of the magnetic orientation of said plurality of magnetic domains, said means for initiating adapted for connection to an external power source; means for producing a signal indicative of the reversal of a majority of said magnetic domains, said means for producing a signal located proximate to said ferromagnetic conductive element, and spaced apart from said means for initiating; and carrier means carrying at least said conductive element for securely positioning at least said conductive element, and for allowing attachment to a substrate.