Patent ID: 9684090
Date: 2017-06-20
CPC Classifications: G01V

Claim:
1. A nulling utility locator, comprising: a transmitter element comprising: a signal generation circuit for generating a first transmit signal and a second transmit signal; a first transmit antenna element coupled to a first output of the signal generation circuit for generating a first magnetic field signal, based on the first transmit signal, for inducing a first current flow component in a buried conductor; and a second transmit antenna element coupled to a second output of the signal generation circuit for generating a second magnetic field signal, based on the second transmit signal, for inducing a second current flow component in the buried conductor; a sensing element comprising a magnetic field receiving antenna element to receive the first magnetic field signal, the second magnetic field signal, and a third magnetic field signal generated from the first and second current flow components in the buried conductor; and an electronic circuit for processing the received first magnetic field signal and the received second magnetic field signal to at least partially cancel each other, and determining, based at least in part on the received third magnetic field signal, information associated with the buried utility, the electronic circuit comprising an analog-to-digital converter for converting one or more output signals from the magnetic field receiving antenna element to one or more digital signals; and a processing element for processing the one or more received signals to at least partially cancel digital signal components of the first magnetic field signal and the second magnetic field signal by nulling, and to process digital signal components of the received third magnetic field signal to determine the information associated with the buried utility.