Magnetic Locating

Principles of Magnetic Locating

The locator finds ferromagnetic objects by sensing the magnetic field radiated by the object. The locator contains two sensor coil assemblies that are precisely spaced and electronically balanced to achieve a near magnetically-balanced operating condition. In a uniform magnetic field, such as the earth’s field, the two sensor coils maintain a magnetically-balanced status, because both of the coils experience the same magnetic lines of force. However, when a ferromagnetic object is approached, the field strength and angle of the magnetic lines upon each sensor is different. This difference, although minute, is enough to offset the critical balance and produce an audible indicating signal. When no ferromagnetic objects are present, the speaker emits a steady low-frequency tone. As the object is approached, the audio frequency increases until the center of the object is directly beneath the locator’s lower tip sensor. The frequency peaks and then decreases as the object is passed. The peak indicates the exact location of the object. Nonferrous objects do not affect the locator. Objects made of brass, aluminum, copper, etc. are ignored.

The range of a magnetic locator is relative to the size, orientation and mass of the iron/steel object. A quality magnetic locator is capable of detecting a large steel object like a 55-gallon drum at 15 feet deep.

How to Use a Locator

https://www.youtube.com/watch?v=sTFIUyL0-Ow

Walk slowly, sweeping the locator back & forth in front of you. If your target is small or very deep, use a higher Gain setting and walk slow, with a slower sweeping motion. Normally a medium setting on the GAIN and a little less than normal walking pace will do fine.

NOTE: Any ‘ferrous’ metal objects on your person, such as watches, pocket knives, large belt buckles, cell phones and steel-toed shoes will interfere if the locator is brought too close to them, or is operated on the higher setting.

Upon locating the target using the “Search or Survey” method, you can detect the exact location of a target such as a “PK”, “Mag Nail”, or other steel or iron target by following these steps: 1. Change the GAIN setting to the lowest setting that will still define the target, by using the “GAIN UP” or “Gain Down” button. 2. Bring the locator to a vertical position by simply allowing it to swing vertical, while you hold the unit loosely. 3. Move the locator back & forth in such a fashion as to create an imaginary “X” pattern over the target. 4. Move the center of the imaginary “X” directly over the target by positioning the crossing position of the “X” at the “Peak” of the signal response.

https://www.youtube.com/watch?v=jWwKvmCJUv0

The recommended search position is a 45° angle from the earth’s surface. Scan the locator pole from side-to-side in a slow sweeping motion while walking in a steady direction. Maintain a consistent height above the ground during the side-to-side sweeping motion. Once the object being searched is located, pinpointing the object’s location can be accomplished by holding the locator vertically and sweeping it in an “X” pattern until the absolute signal peak is found. The audio sound and visual LCD display will provide the pinpointing results. Your magnetic locator is not only sensitive to buried ferrous objects, but also to items in your possession. The locator is not affected by the presence of nonferrous objects, such as copper, aluminum pull tabs or foil, and other forms of trash that may be present in the ground. Snow, ice, water, wood, plastic, concrete, stones, and the ground itself have no effect on the performance of the locator.

*High reading from locator indicating a metal object in the ground.