How to read metal detector tones, Target ID and depth.
Listen, compare the display, then check the same spot from another direction. A detector response is evidence to investigate, not a guaranteed identification.
Begin with your exact model and firmware
Find your original manual, select the matching mode and note any custom tone settings. Add your owned detector and coil to your member locker. Different ID scales and control names cannot be compared as if their numbers were interchangeable.
Use tones, ID and depth together
On EQUINOX 700/900, Target ID runs from −19 to 99; its iron region is −19 to 0. Tone-break settings are separate controls. That example is specific to those models, not a universal iron, gold or silver chart. The depth gauge is approximate and assumes a coin-sized target. Minelab manual: depth gauge, tone break and Target ID sections.
FORS CoRe can report different IDs for one object because of orientation, depth, corrosion or ground conditions. A deep or small signal may have no ID. Nokta manual: Target ID and ID masking, printed pp. 22–23.
Check a signal before deciding what it means
- Mark the repeatable center without starting to dig.
- Keep your coil control consistent, then sweep again across the spot from another direction.
- Write down repeatability, tone changes and the range of IDs, including a missing ID.
- Compare with a known target under safe, permitted conditions. Keep ambiguous findings unknown.
Aluminum foil and aluminum pull tabs are non-ferrous. A non-ferrous response does not establish a precious metal. Never use a high ID as a depth measurement or assume tone pitch alone tells you depth.
If the detector chatters, diagnose one cause at a time
Check the exact manual’s interference procedure and coil connection first. Noise cancel addresses electrical interference; ground balance addresses ground response. Sensitivity affects responsiveness and can also expose more noise. They are different controls. Avoid changing them all at once. EQUINOX 700/900 manual: sensitivity, noise cancel and ground balance.
Follow the model-specific settings guide and keep a baseline note. Discrimination may silence wanted signals as well as unwanted ones; record no-detection outcomes too.
Manufacturer sources checked October 6, 2026. These are original learning steps, not an SSL physical test or an authenticity assessment. Obtain permission before searching or recovering a target.