Metal Detector Terms Part ii

Faint Signal: A sound characteristic of metal detector targets that are sometimes deeply buried or very small in size.

False Signal: An erroneous signal created by over shoot, ground voids or highly mineralized hot rocks. See also Back-Reading.

Faraday-Shield: A metal foil wrapping of the searchcoil windings or metallically painted searchcoil housing interior for the purpose of eliminating electrostatic interference caused by wet vegetation.

Ferrous: Descriptive of any iron or iron bearing material.

Ferrous Oxide: An oxidized particle of iron which generally becomes nonconductive and makes up the natural negative ground mineral matrix. Hematite, which is also iron oxide (Fe203) will respond as positive or metallic. See also Black Sand.

Frequency: The number of complete alternating current cycles produced by the transmit oscillator per second. Measured in cycles per second. VLF Very Low Frequency = 3 to 30 kHz; LF Low Frequency = 30 to 300 kHz;MF Medium Frequency = 300 to 3000 kHz; HF High Frequency = 3 to 30 MHz.

Frequency Shift: A feature which suppresses the audio interference (cross-talk) between two detectors using identical transmit frequencies in close proximity.

DetectionNet Metal Detectors

Eddy Currents: Small circulating currents produced on the surface of metal by the transmitted electromagnetic field. These currents then produce a secondary electromagnetic field which is then detected by the search coil receiver windings resulting in inductive imbalance between the windings.

Electromagnetic Field: An invisible force extending from top and bottom of the searchcoil created by the flow of alternating oscillator frequency current around the transmit winding. See also Detection Pattern.

Electronic Pinpointing: An automated detuning feature which narrows signal response for the purpose of target pinpointing.

Elliptical Coil: A searchcoil with an ellipse shape. This coil can be either concentric or widescan type.

Ground Balance: A state of operation using specialized circuitry to ignore the masking effect that iron ground minerals have over metal targets.

Ground Balance – Factory Preset: A feature which eliminates the manual ground balance control and its adjustment from the operator’s setup procedure. This adjustment is performed internally by the factory to optimize operation over an average range of nonconductive soils.

Ground Balance – Manual Adjusted: A feature requiring a manual control adjustment procedure to neutralize the effects of negative minerals in the search matrix.

Ground Balance – Self Adjusting: A feature which senses change in ground mineral content and continuously readjusts the ground balance while in operation. Sometimes called Ground Tracking or Automatic Ground Balance.

Ground Filter: Complex circuitry found in motion-type detectors which separates mineral signal from the metal signal allowing it to be further processed by the discrimination circuitry.

Matrix: Refers to the total volume of ground penetrated by the transmitted electromagnetic field, which may contain varying amounts and combinations of minerals, metals, salts and moisture.

Metal: Metallic substances such as iron, foil, nickel, aluminum, gold, brass, lead, copper, silver, etc.

Metal Detectorist: A person operating a metal detector in the field. This name is preferred by many over Treasure Hunter.

Meter: A detector component that provides visual information to aid in target identification. Meters feature either an LCD or needle indicator which may display intensity of signal, target depth, target identification, type of metal, or battery condition.

Mineral-Free Discriminator: Any metal detector that can reject or ignore trash metals while simultaneously balancing ground mineralization.

Mineralized Ground: Any soil that contains conductive or nonconductive components.

Mode: A condition of operation, selected by the operator, for specific desired function(s).

Motion Discriminator: A detector type that requires searchcoil motion to activate its simultaneous ground balance and discriminate functions. See also Mineral-Free Discriminator and VLF/TR.

Hand Held: A metal detector configuration whereby the operator holds a shaft or handle which supports the searchcoil and control housing. Also called pole mount.

Head: See Searchcoil.

Hz or Hertz: Cycles per second. See also Frequency.

Hip Mount: See Body Mount.

Hot Rock: A rock which contains a higher concentration of nonconductive ground minerals than the surrounding matrix to which the detector is balanced. A metallic (positive) response will be heard in the motion and non-motion modes and a null or negative drop in threshold is heard in the all-metal, ground balance mode over these rocks.

Isolator: A nonmetal stem which attaches the searchcoil to the control shaft eliminating metallic interference in the detection pattern. On some detectors, the entire lower shaft is made of a nonmetal substance.

kHz or Kilohertz: 1000 cycles per second. See also Frequency.

LCD or Liquid Crystal Display: Used on a metal detector as a graphic visual indicator same as a meter/needle indicator.

LED or Light Emitting Diode: A semiconductor which produces an illuminated visual response.

Loop: See Searchcoil.