Digital processor sensor loop detector and method

A conveyor bet rip detection system for detecting damage to moving conveyor belt comprising:

• a conveyor system having a conveyor belt and associated drive operatively connected to the conveyor belt:
• conductive sensor loops adapted to be placed along a length of the conveyor belt;
• a digital excitation frequency generator providing excitation signals at a frequency and having a fixed duration:
• a master head transmitting the excitation signals to the conductive sensor loops;
• a detector head providing received signals in response to detecting currents in the conductive sensor loops corresponding to respective excitation signals;
• and
• a digital received signal analyzer analyzing received signals after expiration of the fixed duration of respective excitation signals to provide signal states representing loop present and loop not present states of the conductive senor sensor loops.

A method of determining a qualitative state of a conveyor belt comprising:

• applying a first excitation signal having a first frequency to a first sensor loop carried by a conveyor belt;
• detecting a first received signal from the first sensor loop corresponding to the first excitation signal;
• performing a fast Fourier transform on the first received signal to provide a first received signal frequency spectrum;
• identifying magnitude and phase values at the first frequency in the respective received signal frequency spectrum;
• and
• determining a qualitative state of the first sensor loop in response to the magnitude and phase values.

A method of determining a qualitative state of a conveyor belt comprising:

• applying a first fixed duration excitation signal having a first frequency to a first sensor loop carried by a conveyor belt;
• detecting a corresponding first received signal from the first sensor loop;
• after expiration of the fixed duration;
• generating magnitude and phase values for the corresponding first received signal;
• and
• determining a qualitative state of the first sensor loop in response to the magnitude and phase values.

A method of determining a qualitative state of a conveyor belt comprising:

• applying a first excitation signal having a first frequency to a first sensor loop carried by a conveyor belt;
• detecting a corresponding first received signal from the first sensor loop;
• generating magnitude and phase values for the corresponding first received signal;
• determining a qualitative state of the first sensor loop in response to the magnitude and phase values;
• selecting a second frequency having a noise magnitude less than a noise magnitude of the first frequency;
• and
• applying a second excitation signal having the second frequency to the first sensor loop, wherein the first excitation signal has a fixed duration and the method further comprises allowing the fixed duration of the first excitation signal to expire prior to generating magnitude and phase values for the corresponding first received signal.