US 8,428,706 B2 · Sheet conductance/resistance measurement system

Abstract

An apparatus for testing of electrical or physical properties of a material include a single coil sensor mounted adjacent to a sample of the material. Sheet conductance of a wide variety of materials may be measured using the single coil to determine if the material conforms to generally accepted standards for the use to which the material will be put. In some examples, the material is a semiconductor wafer or flat panel. In other examples, the material is the body tissue of a patient. A non-invasive technique using the apparatus is also disclosed for monitoring the health of patient tissue such as musculature, and/or to determine whether healthy circulation is present, by measuring the conductance of the patient tissue in response to a magnetic field applied by the single coil. The single coil may be hand held, or it may be movable using an automated positioning system under computer control.

Claims13

Dependent claims

A system for measuring conductance of a material sample, comprising:

a coil for creating a magnetic field adjacent to a sample to be tested;
an oscillator connected to the coil for applying a voltage to the coil;
and
an automatic gain control circuit connected to the oscillator for sensing a voltage change caused by the sample when the sample is positioned adjacent to the coil and exposed to the magnetic field;
wherein the voltage change is proportional to a conductance of the sample;
and
wherein the system further comprises a movable housing, the coil, oscillator and automatic gain control circuit are contained within the housing such that a portion of the coil is positionable adjacent the sample to expose the sample to the magnetic field;
and
wherein the system further comprises an adjustment assembly connected to the movable housing to enable movement of the movable housing to adjust the position of the coil with respect to the sample along at least two mutually perpendicular axes such that multiple sample points can be measured using the coil.

6 more elements

A system for measuring conductance of a material sample, comprising:

a coil for creating a magnetic field adjacent to a sample;
an oscillator connected to the coil for applying a voltage to the coil;
an automatic gain control circuit connected to the oscillator for sensing a voltage change caused by the sample when the sample is positioned adjacent to the coil and exposed to the magnetic field, the voltage change being proportional to a conductance of the sample;
a movable housing containing the coil, oscillator and automatic gain control circuit, wherein the automatic gain control circuit and oscillator are mounted within the movable housing directly adjacent the coil;
and
an adjustment assembly connected to the movable housing to enable movement of the movable housing to selectively adjust the position of the coil with respect to the sample along three mutually perpendicular axes.

3 more elements

Dependencies are inferred from the claim text.

Sheet conductance/resistance measurement system

Life of this patent

Sheet conductance/resistance measurement system

Life of this patent

Abstract

Claims13