Patent ID: 8314608
Filing Date: 2012-11-20
Classification: G01R

Abstract:
1. A method of determining a distance to a ferrous material comprising: providing a plurality of magnetometers spaced at varying distances from a ferrous material; detecting a ferrous material with each of the plurality of magnetometers individually; establishing one of the plurality of magnetometers as a primary magnetometer; obtaining sensor readings from each of the plurality of magnetometers; forming a first ratio between the difference in the sensor reading of the primary magnetometer and a sensor reading from a first magnetometer of the plurality of magnetometers and the difference in the sensor reading of the primary magnetometer and a sensor reading from a second magnetometer of the plurality of magnetometers; forming a second ratio between the difference of a distance to a ferrous material from the primary magnetometer inversely cubed and the distance to a ferrous material from the first magnetometer inversely cubed and the difference of the distance to a ferrous material from the primary magnetometer inversely cubed and the distance to a ferrous material from the second magnetometer inversely cubed; setting the first ratio and the second ratio equal to each other; and calculating a distance to the ferrous material from the plurality of magnetometers.