Guide·Metal Detecting

How to Read Your Metal Detector’s Signals (Tones and Target ID)

A metal detector does not just beep, it tells you what is likely buried, if you know how to read it. Learning the tones and target ID is what separates finding treasure from digging up bottle caps. Here is how.

HobbyStack EditorialJune 4, 2026Updated July 13, 20261 min read

Part of the Metal Detecting hobby guideSee the full overview — what it involves, what it costs, and how to start.

Key takeaways

A detector communicates through tone (pitch of the beep) and a target ID number. Together they hint at what kind of metal is below and how deep.
Higher tones and higher target-ID numbers usually mean high-conductivity metals (silver, copper, large coins); low tones/IDs often mean iron, foil, or trash.
"Discrimination" lets you tell the detector to ignore certain (usually low, junky) signals, but beginners should dig a wide range to learn what each signal really is.
A repeatable signal, one that beeps consistently from multiple directions, is far more likely to be a real target than a one-off blip.
The only way to truly learn your machine is to dig. Digging "trash" signals early teaches you what your detector is telling you.

Tones and target ID: your detector talking

A metal detector gives you two main pieces of information about what is under the coil. The first is the tone, the pitch of the beep: most detectors beep low for some metals and high for others, so you learn to associate a high, sweet tone with desirable targets and a low grunt with likely junk. The second is the target ID, a number (often on a screen, roughly 0 to 99) that estimates the target’s conductivity. As a rough rule, high-conductivity metals like silver and copper (and larger coins) read as higher tones and higher numbers, while iron, foil, and pull-tabs tend to read low. The detector may also indicate depth. None of this is perfectly reliable, a rusty nail or a bottle cap can fool the machine, but reading tone and target ID together is how you make an educated guess about what is worth digging before you put a shovel in the ground.

Discrimination: filtering, and why not to over-filter

Modern detectors let you "discriminate", tell the machine to stay silent on certain signal ranges, usually the low, trashy ones like iron and foil, so you only hear the promising targets. It sounds ideal: filter out the junk and only dig treasure. But there is a catch for beginners, and it is important: discrimination is imperfect and can make you miss good finds, because some valuable targets read in ranges near trash, and a bottle cap or a gold ring can sit in surprising places on the scale. Early on, it is far better to run low discrimination and dig a wide variety of signals, because every dig teaches you what a given tone and number actually turned out to be. You are training your ear and your judgement. Crank up discrimination too soon and you never learn what your machine is really telling you, and you may leave good targets in the ground.

Reading a real target, and digging responsibly

Beyond the numbers, experienced detectorists listen to the quality of the signal. A good target usually gives a clear, repeatable beep, sweep the coil over it from several different directions and it responds consistently each time. A signal that only beeps from one angle, or sounds broken and erratic, is more often junk, deep iron, or ground mineralisation. So when you get a hit, sweep it from multiple directions and check whether the tone and ID hold steady before deciding to dig. When you do dig, do it responsibly: cut a neat plug, retrieve the target, and fill the hole back so the ground looks undisturbed, this is basic etiquette that keeps land open to detectorists. And know the rules where you are: always get permission for private land, and be aware many places have laws about where you can detect and what you must report. The real learning, though, comes from digging: the more signals you dig and identify, the better you get at reading your detector before the shovel comes out.

Note

Always get permission before detecting on land you do not own, and check local laws, many areas restrict detecting on protected sites or require you to report certain finds. Responsible detectorists get permission, fill their holes neatly, and follow the rules, which is what keeps land accessible for everyone in the hobby.

Common questions

How do you read metal detector signals?

Two things: the tone (pitch of the beep) and the target ID number. Higher tones and higher ID numbers generally point to high-conductivity metals like silver, copper, and larger coins, while low tones and low numbers often mean iron, foil, or trash. The detector may also estimate depth. None of it is perfectly reliable, but reading tone and target ID together lets you make an educated guess about what is buried before you dig. Digging and checking teaches you what your specific machine’s signals mean.

What does the target ID number mean?

The target ID is your detector’s estimate of the target’s conductivity, shown as a number (often around 0 to 99). Higher numbers usually indicate high-conductivity metals such as silver and copper or big coins, while lower numbers tend to mean iron, foil, and pull-tabs. It helps you guess what a signal is, but it is not foolproof, corroded, oddly shaped, or deep items can read misleadingly. Use the number alongside the tone and signal quality, and confirm by digging, especially while you are still learning your machine.

What is discrimination on a metal detector?

Discrimination is a setting that tells the detector to ignore certain signal ranges, usually the low, junky ones like iron and foil, so it only beeps on more promising targets. It reduces digging trash, but it is imperfect: some valuable finds read in ranges near junk, so heavy discrimination can cause you to miss good targets. Beginners are usually better off running low discrimination and digging a wide range of signals, because doing so teaches you what each tone and number actually is.

Should beginners dig every signal?

Not literally every one, but far more than you might think. Digging a wide variety of signals early, including "trashy" ones, is how you learn what your detector’s tones and numbers really correspond to, which makes you much better at judging targets later. If you only ever dig the "perfect" signals (or over-use discrimination), you never build that experience and you will miss good finds that read unexpectedly. Think of early digs, even the junk, as training your ear and judgement.

How do I know if a signal is a good target?

Beyond the tone and target ID, listen to the signal’s quality and repeatability. Sweep the coil over the spot from several different directions: a good target usually gives a clear, consistent beep from every angle, while junk or deep iron often sounds broken, erratic, or only responds from one direction. A repeatable signal with a stable tone and ID is much more likely to be worth digging. Checking a hit from multiple angles before digging saves you from a lot of unnecessary holes.

Bottom line

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