Reading your target ID before you dig

Most VLF detectors give you two pieces of information about a target before you dig: a tone, and a numeric target ID (often on a scale like -95 to 95, or 0 to 99 depending on the brand). Learning to read both together, rather than either one alone, is what cuts down on wasted holes.

Tone reflects the conductivity of the target — low-conductivity targets (small gold, foil, some iron) produce low tones, high-conductivity targets (large silver and copper coins) produce high tones, with everything else in between. Numeric ID refines that further and is generally more reliable for identifying a specific target type, but it's not infallible — target depth, orientation, size, and nearby trash can all shift the number.

A few things worth knowing: a stable, repeatable number from multiple directions is far more trustworthy than a single sweep. Two overlapping targets (a coin sitting next to a nail, for instance) often produce a blended, unstable ID that doesn't match either target cleanly — that instability is itself useful information. And target ID accuracy generally drops as depth increases, so a borderline number on a deep target is worth digging on masse-detected sites even if you'd otherwise pass on that ID closer to the surface.

No target ID system replaces digging test targets in your own soil with your own detector — mineralisation, coil type and discrimination settings all shift where a given object reads on the scale.

Looking to buy? Browse our Metal Detectors range.