Universal impedence probe for detection of side-connections through thermoplastic, thermosetting and cementitious liners

1. A method of locating side connections in a conduit having a plastic liner previously positioned in the conduit, the method comprising the steps of:

a. positioning a waveguide probe within the conduit, the probe comprising:

i. an RF signal generator;

ii. an RF signal detector;

iii. a controller controlling the signal generator and signal detector;

iv. an open-ended rectangular waveguide transmitting signals from the signal generator and to signal detector;

v. a probe carriage capable of movement axially down the conduit and positioning the waveguide adjacent to a liner surface and moving the waveguide in a generally circumferential direction along the liner surface; and

iv. a rolling surface offsetting the waveguide a distance of less than about one inch from the liner surface;

b. moving the waveguide along the liner surface with the rolling surface engaging the liner surface;

c. transmitting an RF signal through the wave guide toward the liner surface;

d. measuring a reflected signal from the RF transmission;

e. analyzing the reflected signal to determine a change in at least one electro-magnetic property in a space behind the liner.

2. The method of claim 1 wherein the change in electro-magnetic property is dielectric constant.

3. The method of claim 2 wherein the controller determines a change in the dielectric constant by detecting a change in power of the reflected signal.

4. The method of claim 3 wherein the decrease in power is quantified as a change in voltage.

5. The method of claim 1 wherein the transmitted RF signal is within the range of about 3 GHz to about 20 GHz.

6. The method of claim 1 wherein the waveguide is rectangular in cross-sectional shape.

7. The method of claim 6 wherein the waveguide has a cross-sectional area of about 0.25 in 2 to about 2.5 in 2 .

8. The method of claim 1 wherein the probe carriage further includes a cutter device capable of forming an aperture in the liner.

9. The method of claim 1 wherein the conduit in which the probe is positioned has a first dielectric constant and a side conduit forming the side connection has a material with a second dielectric constant positioned within the side conduit.

10. The method of claim 9 wherein the material with a second dielectric constant is water.

11. The method of claim 9 wherein the second material is a plug containing a saline solution or conductive metal salt crystals.

12. The method of claim 1 wherein the wave guide is rectangular and the short dimension of the wave guide is between 30% and 100% of than the diameter of a side connecting member intersecting the conduit.

13. The method of claim 1 wherein a long dimension of a rectangular wave guide is 90% to 140% of the diameter of the side connecting member.

14. The method of claim 1 , further taking a first series of circumferential readings at a first radial increment where the increment is equal to or less than a diameter of an expected side connection.

15. The method of claim 14 , wherein once the approximate location of the side connection is detected, taking a second series of circumferential readings at a second radial increment smaller than the first radial increment.

16. A conduit survey apparatus comprising:

a. a carriage capable of movement axially down the conduit;

b. an RF signal generator and an RF signal detector positioned on the carriage;

c. a controller controlling the signal generator and signal detector;

d. a waveguide with an open throat transmitting signals from the signal generator and directing received signals to the signal detector, and

e. a waveguide positioner mounted on the carrier and adapted to selectively engage an interior wall of the conduit, wherein the waveguide guide is connected to the positioner such that the open throat of the waveguide is within about 1 inch of the interior wall when the positioner engages the interior wall.

17. The conduit survey apparatus of claim 16 wherein the waveguide positioner is disc-shaped and both the waveguide positioner and the waveguide are positioned on an adapter body.

18. The conduit survey apparatus of claim 16 wherein the waveguide positioner comprises at least two rollers attached to the waveguide.

19. The conduit survey apparatus of claim 16 wherein a support arm extends from the carriage and an adapter body is positioned on the support arm, and wherein the RF signal generator, the RF signal detector, the controller, the waveguide, and the waveguide positioner are mounted on the adapter body.

20. The conduit survey apparatus of claim 19 wherein support arm is capable of moving the adapter body in a rotative direction relative to a conduit inner surface.