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

摘要

A conduit survey apparatus having a carriage capable of movement axially down a conduit. The carrier includes a radio frequency (RF) signal generator and an RF signal detector positioned on the carriage along with a controller controlling the signal generator and signal detector. The carrier further includes a waveguide with an open throat transmitting signals from the signal generator and directing received signals to the signal detector. Finally, the carrier includes 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.

主权项

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; andiv. 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.