Method for nondestructive/noncontact microwave detection of electrical and magnetic property discontinuities in materials
AssigneeThe John Hopkins University
InventorsJohn C. Murphy, Robert Osiander, Jane W. Maclachlan Spicer
Life of this patent
Estimating the term…
Abstract
Nondestructive/noncontact evaluation of a material for electrical and magnetic property discontinuities, e.g., a dielectric loss or the presence of a conducting contaminant, is accomplished by using microwaves to heat microwave-absorbing regions of the material caused by such discontinuities; monitoring the change in temperature of the material's surface due to the heating of the microwave-absorbing region as a function of time; and detecting the electrical and magnetic property discontinuities, e.g., the dielectric loss or the conducting contaminant, using the change in the material's surface temperature.
Claims29
A method for noncontact detection of electrical and magnetic property discontinuities, the discontinuities each comprising a subsurface microwave-absorbing region in a material, the method comprising the steps of:
- heating directly the subsurface microwave-absorbing regions of the material with microwaves;
- monitoring changes in the temperature of the surface of the material as a function of time, the changes due to the heating of the microwave-absorbing regions;
- and
- detecting the electrical and magnetic property discontinuities in the material using the changes in surface temperature.
A method for noncontact detection of an electrical property discontinuity, the discontinuity comprising a subsurface microwave-absorbing region in a material, the method comprising the steps of:
- heating directly the subsurface microwave-absorbing region of the material with microwaves;
- monitoring a change in the temperature of the surface of the material as a function of time, the change due to the heating of the subsurface microwave-absorbing region;
- and
- detecting the electrical property discontinuity in the material using the change in surface temperature.
A method for noncontact detection of a magnetic property discontinuity, the discontinuity comprising a subsurface microwave-absorbing region in a material, the method comprising the step of:
- heating directly the subsurface microwave-absorbing region of the material with microwaves;
- monitoring a change in the temperature of the surface of the material as a function of time, the change due to the heating of the subsurface microwave-absorbing region;
- and
- detecting the magnetic property discontinuity in the material using the change in surface temperature.
Dependencies are inferred from the claim text.