Transmitter for emitting reference signal to distinguish false signals in cable locating
First Claim
1. A transmitter as part of a cable locating system for use in a region which contains at least first and second in-ground cables, each of which cables includes an electrically conductive component such that, when the first cable is driven at a locating signal frequency to emit a locating signal in an electromagnetic form, the locating signal is coupled to the second cable in a way which causes the second cable to generate a false locating signal in electromagnetic form, said transmitter comprising:
- an apparatus for generating said locating signal frequency for coupling onto the first cable and for transmitting a reference signal, which includes said locating signal frequency modulated thereon such that the reference signal includes a modulation envelope for comparison of the modulation envelope to the locating signal and to the false locating signal at a receiving location to distinguish the locating signal from the false locating signal.
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Accused Products
Abstract
A transmitter is part of a cable locating system for use in a region which contains at least first and second in-ground cables, each of which cables includes an electrically conductive component such that, when the first cable is driven at a locating signal frequency to emit a locating signal in an electromagnetic form, the locating signal is coupled to the second cable in a way which causes the second cable to generate a false locating signal in electromagnetic form. The transmitter generates the locating signal frequency for coupling onto the first cable and for transmitting a reference signal, which includes the locating signal frequency such that the reference signal includes a modulation envelope for comparison of the modulation envelope to the locating signal and to the false locating signal at a receiving location to distinguish the locating signal from the false locating signal.
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Citations
18 Claims
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1. A transmitter as part of a cable locating system for use in a region which contains at least first and second in-ground cables, each of which cables includes an electrically conductive component such that, when the first cable is driven at a locating signal frequency to emit a locating signal in an electromagnetic form, the locating signal is coupled to the second cable in a way which causes the second cable to generate a false locating signal in electromagnetic form, said transmitter comprising:
an apparatus for generating said locating signal frequency for coupling onto the first cable and for transmitting a reference signal, which includes said locating signal frequency modulated thereon such that the reference signal includes a modulation envelope for comparison of the modulation envelope to the locating signal and to the false locating signal at a receiving location to distinguish the locating signal from the false locating signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
Specification