What Target ID Numbers Actually Tell You
Every modern metal detector assigns a number to each target it senses underground. This number — usually displayed on an LCD screen — represents the detector's best estimate of the target's conductivity, which is a physical property of the metal. High-conductivity metals like silver and copper produce high numbers, while low-conductivity metals like gold, lead, and nickel register lower. Iron and ferrous trash typically read at the bottom of the scale or in negative numbers.
The catch is that target ID is an estimate, not a definitive identification. Depth, target orientation, nearby iron, soil mineralization, and the target's shape all influence the number. A deep silver dime can read lower than expected, and a pull tab can mimic a gold ring. Understanding these limitations is what separates productive detectorists from frustrated ones.
How Target ID Scales Work
Different detector manufacturers use different numerical scales, but the underlying physics is the same. Here is how the major platforms map their ranges:
| Brand | Scale Range | Iron/Ferrous Zone | Silver Coin Zone |
|---|---|---|---|
| Minelab (Equinox, Manticore) | -9 to 50 | -9 to 0 | 26–36 |
| Nokta (Legend, Simplex) | 0 to 99 | 0–15 | 70–90 |
| Garrett (AT series, APEX) | 0 to 99 | 0–20 | 75–95 |
| XP (Deus II) | 0 to 99 | 0–15 | 80–95 |
| Fisher (F75, F44) | 1 to 99 | 1–15 | 75–90 |
Regardless of the specific numbers, the concept is consistent: the scale runs from ferrous (iron) on the low end to highly conductive non-ferrous metals on the high end. The middle of the scale is the messy zone — pull tabs, zinc pennies, nickel coins, gold jewelry, and aluminum foil all cluster in overlapping ranges that require experience to interpret.
The Problem Zone: Mid-Range Targets
The most valuable finds in metal detecting — gold rings, early copper coins, old buttons, and colonial-era artifacts — often read in the same range as the most common trash targets. Here is where confusion lives:
Pull tabs read in the mid-to-upper range on most detectors, often overlapping with gold rings and zinc pennies. If you discriminate out pull tabs, you will also reject gold jewelry. Most experienced detectorists accept this overlap and dig everything in the gold ring zone.
Nickel coins read lower than other US coins because nickel is less conductive than copper or silver. On many machines, nickels sit right next to pull tabs and gold rings on the target ID scale. This is why "digging nickels" is a running joke in the hobby — and also why experienced hunters never skip them.
Gold jewelry varies wildly depending on karat, size, and alloy composition. A 14K gold band might read similarly to a pull tab, while a heavy 18K gold bracelet might read closer to a zinc penny. There is no single "gold ring number" — only a range you learn to recognize with experience.
When to Trust Your Numbers — and When Not To
Shallow targets in clean ground produce the most reliable IDs. The closer the target is to the coil and the less interference from surrounding metal, the more accurate the number. A silver quarter at 3 inches will lock on its expected reading consistently.
Deep targets produce unreliable IDs. As depth increases, the signal weakens and the detector has less information to analyze. A deep silver dime might bounce between several numbers or read lower than expected. If a deep target gives you a consistent repeatable signal but the number seems off, consider digging it anyway.
Iron masking distorts everything. When a non-ferrous target sits near iron, the combined signal can confuse the target ID system. The detector might read lower than expected, bounce between iron and non-ferrous numbers, or produce a "blended" number that does not match any known target. Sites with heavy iron contamination require more digging and less reliance on numbers.
Target orientation matters. A coin lying flat presents its full surface to the coil and gives the most accurate reading. A coin on edge presents a thin profile that reads differently — often lower or jumpier. Deep coins migrate to vertical orientations over time, which is why old coins often produce inconsistent IDs.
Experienced detectorists listen to the audio response at least as much as they watch the screen. A clean, crisp, repeatable audio signal that sounds the same from multiple swing directions is a strong dig signal regardless of what the number says. Numbers lie more often than audio does.
Building Your Own Target ID Reference
The fastest way to learn your detector's target ID behavior is to build a test garden. Bury known targets — modern coins, a pull tab, a piece of aluminum, a brass button, a piece of iron — at known depths (2 inches, 4 inches, 6 inches, 8 inches) and practice reading them. Document the numbers each target produces at each depth, and you will quickly develop an intuition that no chart or manual can replicate.
In the field, keep a log of your first 50–100 digs. Write down the target ID number, the depth, and what you actually recovered. After a few sessions, patterns emerge: you will know exactly which numbers produce coins, which numbers produce trash, and which numbers require judgment calls in your specific ground conditions.
Discrimination: When to Use It and When to Dig Everything
Target ID enables discrimination — the ability to tell your detector to ignore targets in certain numeric ranges and only alert on others. This is useful for cherry-picking silver coins in a modern park, but dangerous at historic sites where valuable relics read all over the scale.
The general rule: discriminate when you are hunting a specific target type in a known environment (coins in a modern park), and run in All-Metal or minimal discrimination when exploring new or historic sites where anything could be valuable. Iron rejection is usually safe to leave on, but even that should be reduced at heavily ironed sites where good targets hide behind nails.
Frequently Asked Questions
Target ID numbers represent the detector's estimate of a buried target's electrical conductivity. Higher numbers indicate more conductive metals like silver and copper. Lower numbers indicate less conductive metals like gold, nickel, and lead. Iron and ferrous trash typically read at the bottom of the scale. The numbers help you decide what to dig, but they are estimates, not definitive identifications.
Bouncing or unstable target ID usually means the target is deep, oriented on edge, near iron, or composed of mixed metals. It can also indicate multiple overlapping targets. A signal that bounces but produces a consistent audio response from multiple swing directions is often still worth digging — many valuable old finds produce jumpy IDs.
There is no single gold ring number. Gold jewelry varies widely in target ID depending on karat, size, thickness, and alloy composition. On most detectors, gold rings read in the mid-range — often overlapping with pull tabs, zinc pennies, and nickel coins. Experienced hunters dig the mid-range rather than discriminating it out.
It depends on the site. At modern parks where you are hunting coins, discrimination helps filter trash and speeds up your hunt. At historic sites, relic fields, or any new-to-you location, run with minimal discrimination because valuable finds can read anywhere on the target ID scale. Many experienced detectorists run All-Metal mode most of the time.
Build a test garden with known targets at known depths and practice reading them. Slow your swing speed, keep the coil close to the ground, and listen to the audio response in addition to watching the screen. Check targets from multiple swing directions — a real non-ferrous target should produce a consistent response regardless of approach angle.