Capacitive plate dielectrometer method and system for measuring dielectric properties

• US 7,479,790 B2
• Filed: 11/09/2006
• Issued: 01/20/2009
• Est. Priority Date: 11/09/2006
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Choi, Christopher Y.
• Primary Examiner(s): Nguyen; Vincent Q
• Application Number:
  US11/595,066
• Publication Number:
  US 20080111559A1
• Time in Patent Office: 803 Days
• Field of Search: 324/663, 324/547, 324/601
• US Class Current: 324/663
• CPC Class Codes: G01R 27/2641 of plate type, i.e. with the sample sandwiched in the middle

Abstract

A capacitive plate dielectrometer method and system is provided that is used to measure dielectric properties, such as permittivity, of a small sample test material at a low frequency. The capacitive plate dielectrometer method and system calibrates the capacitive plate dielectrometer with a plurality of standard dielectric materials and the sample test material is rotated in the capacitive plate dielectrometer to allow measurement of several electric field directions.

Claims

1. A method for measuring dielectric properties of a test material using a capacitive plate dielectrometer device, comprising the steps of:

obtaining a small sample of the test material having a size and shape that allows the sample test material to fit within the capacitive plate dielectrometer;

attaching a connecting cable to a measuring device and calibrating the connecting cable;

connecting the calibrated connecting cable to the capacitive plate dielectrometer;

calibrating the capacitive plate dielectrometer with a plurality of standard dielectric materials, wherein each standard dielectric material is inserted into the capacitive plate dielectrometer, and dielectric property data is collected by the measuring device for each standard dielectric material; and

,

inserting the sample test material into the capacitive plate dielectrometer and collecting dielectric property data using the measuring device.

2. The method of claim 1 wherein the dielectric properties of the standard dielectric materials and the sample test material are measured at a frequency in the range of from about 50 megahertz to about 600 megahertz.

3. The method of claim 1 wherein a dielectric property measured is the permittivity of the standard dielectric materials and the permittivity of the sample test material.

4. The method of claim 1 wherein the size of the sample test material is less than about five inches in height and less than about five inches in width.

5. The method of claim 1 wherein the sample test material is a three inch honeycomb cube.

6. The method of claim 1 wherein the connecting cable is a coaxial cable that is calibrated using open, short, and load standards.

7. The method of claim 1 wherein the measuring device is a combination of a network analyzer and a computer having data acquisition software.

8. The method of claim 1 wherein the standard dielectric materials are selected from the group comprising polystyrene foam, polystyrene plastic, alumina, and polytetrafluoroethylene.

9. The method of claim 1 wherein the capacitive plate dielectrometer is calibrated with three standard dielectric materials.

10. The method of claim 1 further comprising the step, prior to calibrating the capacitive plate dielectrometer with a plurality of standard dielectric materials, of leveling the capacitive plate dielectrometer with a leveling device.

11. A method of measuring the permittivity of a test material in a frequency range of from about 50 megahertz to about 600 megahertz, using a capacitive plate dielectrometer device, comprising the steps of:

obtaining a sample of the test material having a size less than about five inches in height and less than about five inches in width;

attaching a coaxial cable to a measuring device having data acquisition software and calibrating the connecting cable;

connecting the calibrated connecting cable to the capacitive plate dielectrometer;

calibrating the capacitive plate dielectrometer with a plurality of standard dielectric materials, wherein each standard dielectric material is inserted into the capacitive plate dielectrometer and permittivity data is collected by the measuring device for each standard dielectric material; and

,

inserting the sample test material into the capacitive plate dielectrometer and collecting permittivity data using the measuring device, and wherein the sample test material is rotated in the capacitive plate dielectrometer to allow measurements of three electric field directions.

12. The method of claim 11 wherein the sample test material is a three inch honeycomb cube.

13. The method of claim 11 wherein the measuring device is a combination of a network analyzer and a computer having data acquisition software.

14. The method of claim 11 wherein the standard dielectric materials are selected from the group comprising polystyrene foam, polystyrene plastic, alumina, and polytetrafluoroethylene.

15. The method of claim 11 further comprising the step, prior to calibrating the capacitive plate dielectrometer with a plurality of standard dielectric materials, of leveling the capacitive plate dielectrometer with a leveling device.

16. A system for measuring dielectric properties of a test material, the system comprising:

a capacitive plate dielectrometer device;

a measuring device with data acquisition software, such that the measuring device has a capability to measure frequency in the range of from about 50 megahertz to about 600 megahertz;

a calibrated connecting cable for connecting the measuring device to the capacitive plate dielectrometer;

a plurality of standard dielectric materials, wherein each standard dielectric material is inserted into the capacitive plate dielectrometer and dielectric property data is collected by the measuring device for each standard dielectric material; and

,

a small sample of the test material having a size and shape that allows the sample to be inserted into and fit within the capacitive plate dielectrometer, such that dielectric property data of the sample is collected by the measuring device.

17. The system of claim 16 further including a leveling device for leveling the capacitive plate dielectrometer.

18. The method of claim 16 wherein the measuring device is a combination of a network analyzer and a computer having data acquisition software.

19. The system of claim 16 wherein the sample test material is a three inch honeycomb cube.

20. The system of claim 16 wherein the standard dielectric materials are selected from the group comprising polystyrene foam, polystyrene plastic, alumina, and polytetrafluoroethylene.