Metal detecting has its own language — and it matters. Pick up a manual, spend ten minutes on a forum, or read a product description, and you'll run into terms like ground balance, discrimination pattern, and time constant before you've even turned the machine on. Knowing what they actually mean changes how you set up your detector, how you read its signals, and ultimately what you dig.
This glossary covers 107 terms across the full spectrum of the hobby: the underlying technology (VLF, Pulse Induction, BBS, FBS, MPS), coil types and how they shape your search pattern, ground conditions and how to compensate for them, battery chemistry, discrimination methods, and the audio and visual target ID systems built into modern detectors. Terms specific to gold prospecting, relic and coin hunting, and beach detecting are included too — each discipline has its own concepts and trade-offs that don't always overlap.
Entries run alphabetically. Cross-references connect related terms so you can follow a concept through — understanding time constant makes more sense once you've read eddy currents, for example. Where a term ties directly to a type of detector or piece of equipment, there's a link to the relevant part of the store or a more detailed guide.
A · B · C · D · E · F · G · H · I · J · L · M · N · O · P · Q · R · S · T · U · V · Z
A
ACCU-TRAK
ACCU-TRAK is a continuous automatic ground tracking system that measures ground mineralisation in real time as the coil is swept. Any changes in mineralisation are analysed instantly and the ground balance level is adjusted accordingly.
This ensures the detector is always correctly ground balanced, operating at maximum depth and sensitivity with minimum operator intervention — particularly valuable in ground with rapidly varying mineral content.
Learn more: How Do Metal Detectors Work?
Air Test
An air test is a bench test performed by passing a target through the coil's field while the detector is held off the ground. It is used to gauge approximate detection depth and observe target ID responses in a controlled, interference-free environment.
Air test results are always optimistic. Real-world performance in mineralised soil will be shallower due to ground attenuation and signal cancellation effects. Use air tests for comparison purposes, not as an absolute depth predictor.
New to detecting? Getting Started Guide
Alkaline Batteries
Alkaline batteries are non-rechargeable single-use batteries available in standard sizes (AA, C, D) at 1.5 V per cell. They are the most widely available battery type globally, making them a practical choice when detecting in remote locations where recharging is not possible.
Performance degrades gradually as voltage drops, which can affect detector sensitivity toward the end of a set. Many detectors include a low-battery indicator for this reason.
Shop: Metal Detector Batteries
All Metal
All metal mode operates with no discrimination active. Every conductive and ferrous target produces a response regardless of its properties, maximising detection depth at the expense of selectivity.
All metal mode is useful for locating deeply buried targets that discrimination might miss, and is the standard operating mode for most gold prospecting detectors.
Amplifier
An amplifier is an electronic circuit that increases the amplitude (strength) of an electrical signal — either an audio signal (sound) or a radio-frequency signal (electromagnetic). In metal detectors, amplifiers boost the faint received signal from the coil before it is processed by the discrimination and target ID circuitry.
Analogue
Analogue refers to signals in which information is encoded as a continuously variable voltage or current level. Early metal detectors were entirely analogue. Modern detectors convert analogue coil signals to digital as early as possible in the signal chain for more accurate processing, though the audio output is always converted back to analogue before reaching the speaker or headphones.
See also: Digital
Auto Tune
Auto Tune is a feature that shifts the detector's operating channel to reduce the effect of environmental electromagnetic noise. When an external noise source produces frequencies that coincide with the detector's operating channel, the detector becomes prone to falsing. Auto Tune shifts the channel up or down to avoid this overlap.
See also: Noise Cancel, EMI
Arm Cuff / Armrest
The arm cuff (also called an armrest) is the padded forearm support near the top of the detector shaft. It distributes the weight of the detector across the forearm rather than the wrist, reducing fatigue on long detecting sessions. Many detectorists add aftermarket cuffs for better padding or a more ergonomic fit.
See also: Shaft / Stem
B
BBS (Broad Band Spectrum)
BBS simultaneously transmits, receives, and analyses a broad band of multiple frequencies. Providing the electronics with information across a range of frequencies allows better target identification accuracy and greater depth than single-frequency VLF, and significantly reduces false signals from ground minerals — even on saltwater beaches.
See also: FBS, Multi-frequency
Learn more: Metal Detector Technologies Explained|Shop Multi-Frequency Detectors
C
Cache
A cache is a deliberately hidden hoard of valuables — coins, jewellery, precious objects, or artefacts — buried together, often in a container. Caches can date from any historical period and typically produce an unusually strong, wide, or repeating signal over a small area. Finding a cache is considered one of the most significant discoveries a detectorist can make.
Learn more: Where To Go Metal Detecting
CO (Conductivity)
CO is the abbreviation for conductivity as displayed on two-dimensional discrimination screens. The CO axis typically runs horizontally, with higher values to the right indicating more conductive targets such as large silver coins.
See also: Conductivity, Smartfind, FE
Coil Cover / Skidplate
A coil cover (also called a skidplate) is a replaceable protective plastic shield fitted to the underside of the search coil. It prevents abrasion and scratching from rocks and rough terrain, extending the coil's working life. Coil covers should be checked regularly and replaced when worn thin, as a cracked cover can allow moisture ingress and coil damage.
Shop: Coil Covers & Skidplates
Coin, Jewellery & Relic Hunting
Coin, jewellery, and relic hunting is the most common form of metal detecting, focused on recovering historical and modern metal objects from the soil rather than gold nuggets. Detectors optimised for this discipline prioritise discrimination accuracy, clear target ID displays, and balanced performance across a range of target conductivities.
See also: Gold Prospecting, Discrimination
Concentric Coil
A concentric coil has an inner circle and outer circle wire winding arrangement producing a cone-shaped detection field centred beneath the coil. This shape makes target pinpointing intuitive, as the signal peak is directly under the coil's centre.
Concentric coils require more sweep overlap than Double-D coils for thorough ground coverage and can be noisier in heavily mineralised soil. They are generally better suited to milder ground conditions.
See also: Double-D Coil, Monoloop Coil
Shop: Search Coils|Learn more: Understanding Metal Detector Coils
Conductivity
Conductivity measures how freely electrical current flows through a target. Highly conductive targets (low resistance) such as large silver coins produce strong, long-duration eddy currents and high target ID numbers. Poorly conductive targets (high resistance) such as thin gold jewellery produce weaker, shorter-duration currents and lower target IDs.
Conductivity is one of the two main axes used in discrimination — the other is ferrous content.
See also: Time Constant, Resistance
Continuous Wave
Continuous wave is a metal detecting technology in which the search coil transmits a continuously alternating sine-wave electromagnetic field into the ground. VLF (Very Low Frequency) is the most common implementation. The received signal is analysed for phase shift and amplitude change caused by nearby metal targets.
See also: VLF, Pulse Induction
Learn more: Metal Detector Technologies Explained
Control Box
The control box houses the detector's electronic circuitry. It generates the transmit signal sent to the search coil and processes the received signal to produce audio tones, target ID numbers, and discrimination responses. Settings controls, a display screen, and battery compartment are typically integrated into the control box.
Current
Current is the flow of electrical charge, measured in amperes (A). Battery and charger specifications quote current output in milliampere-hours (mAh). Within a metal detector's operation, eddy currents are induced into metal targets by the transmitted electromagnetic field — it is these eddy currents that the receive coil ultimately detects.
See also: Voltage, Eddy Currents
Classifier / Sifter
A classifier is a mesh screen — available in multiple hole sizes — used to separate material by particle size before processing it in a gold pan, sluice box, or concentrator. Removing oversized gravel and rocks reduces the volume of material to process, speeds up recovery, and prevents large rocks from disturbing fine gold during panning. Classifiers can be stacked from coarsest to finest for progressive sizing, though most field prospectors use a single mesh size matched to their recovery method.
See also: Gold Panning, Sluice Box, Trommel
Concentrator
A concentrator is a device that uses water flow, vibration, or centrifugal force to separate heavy minerals (including gold) from lighter waste material. Common types for small-scale prospecting include vibrating bowl concentrators (such as the Blue Bowl, which uses a gentle upwelling of water and vibration) and spiral wheel concentrators (a rotating wheel that spins through a water bath). In both cases, the high specific gravity of gold causes it to settle and be retained while lighter material is carried away. Concentrators are typically used as a secondary cleanup step after sluicing or panning to further refine the concentrate.
See also: Gold Panning, Sluice Box, Riffle
D
Depth
Depth in metal detecting refers to how far below the surface a target is buried. Detection depth is influenced by target size and conductivity, soil mineralisation level, coil size, detector technology, and sensitivity settings. As a general rule: larger coils, lower operating frequencies, and pulse induction technology achieve greater depth than smaller coils and higher frequencies.
Detectorist
A detectorist is a person who uses a metal detector, either as a hobby or professionally. The term is preferred within the hobby community over the more sensationalised "treasure hunter," reflecting the responsible and often historically significant nature of the pursuit.
Just starting out? Getting Started With Metal Detecting|Best Beginner Detectors (2026)
Digital
Digital signals use only two discrete states — high (1) and low (0) — processed in binary. Modern metal detector designs convert analogue coil signals to digital early in the processing chain, enabling complex filtering algorithms, precise target ID calculation, lighter circuits, and greater noise rejection compared to purely analogue designs.
See also: Analogue
Discrimination
Discrimination is a detector's ability to classify buried targets by their conductive and ferrous properties so the operator can decide whether to dig. The four main types are:
- Variable discrimination — a continuous knob that rejects increasingly valuable target ranges as it is turned up.
- Iron Mask / Iron Reject — used primarily in gold prospecting to silence ferrous junk.
- Notch discrimination — accepts or rejects specific target ID ranges.
- Two-dimensional (Smartfind-style) — the most advanced form; targets are plotted by both ferrous and conductive properties on a 2D display, enabling highly selective discrimination patterns.
Learn more: Metal Detector Technologies Explained|Metal Detecting FAQ & Tips
Discrimination Pattern
A discrimination pattern is a graphical representation of accepted and rejected target zones on a one- or two-dimensional display. Shaded areas represent rejected targets; unshaded areas represent accepted targets. Operators customise patterns to block common junk (pull-tabs, foil) while keeping the zones that correspond to desirable finds.
See also: Discrimination, Smartfind
Double-D Coil (DD Coil)
A Double-D coil uses two overlapping D-shaped wire windings. The overlapping arrangement creates a narrow, blade-shaped detection field running through the centre of the coil rather than the cone-shaped field of a concentric coil.
Benefits include improved stability in mineralised and saltwater beach conditions, less overlap required for thorough coverage, and the ability to discriminate ferrous targets when iron reject is active. The blade field pattern also makes it harder for iron objects to mask adjacent non-ferrous targets.
See also: Concentric Coil, Monoloop Coil
Shop: Search Coils|Learn more: Understanding Metal Detector Coils
DVT (Dual Voltage Technology)
DVT is an advanced Pulse Induction technology that transmits pulses at two voltage levels in combination with Multi Period Sensing. The dual voltage levels increase total power transmitted into the ground while also allowing more of the ground response to be removed from the received signal, delivering greater depth and sensitivity in extremely mineralised soils.
See also: MPS, Pulse Induction
Learn more: Metal Detector Technologies Explained
Digging Tool / Digger
A digging tool (also called a digger, trowel, or hand pick) is the hand tool used to excavate targets once their location has been determined. Good detecting diggers are serrated on one edge for cutting through roots and turf, narrow enough to make a small plug, and robust enough to handle compacted soil. Purpose-made detecting diggers (such as the Lesche and King of Spades) are specifically balanced and sharpened for this use. Using the right tool minimises ground damage and speeds up recovery significantly.
See also: Pinpointing, Pinpointer
Shop: Shovels, Diggers & Picks
E
Eddy Currents
Eddy currents are small electrical currents induced into a conductive target when it enters the alternating electromagnetic field produced by a metal detector's search coil. These currents flow in loops within the target and generate their own secondary magnetic field, which the receive coil picks up and the detector's circuitry analyses to determine target properties.
Electromagnetic Field
An electromagnetic field is the physical field produced by alternating electrical current flowing through a conductor. The search coil generates a transmit electromagnetic field that extends into the ground. When this field intersects a metal target, the target generates a secondary field that the coil receives. The illustration shows the transmit field (blue) and the received target field (yellow).
Learn more: How Do Metal Detectors Work?
EMI (Electromagnetic Interference)
Electromagnetic Interference (EMI) is unwanted electrical noise from external sources that disrupts a metal detector's operation. Common sources include high-voltage power lines, radio and cell towers, airport radar, agricultural electrical fencing, and other nearby detectors. EMI typically manifests as random falsing, threshold instability, or erratic target IDs.
Managed via Noise Cancel or Auto Tune functions, and by physically relocating away from interference sources where possible.
See also: Noise Cancel, Auto Tune, Environmental Noise
Environmental Noise
Environmental noise originates from power lines, underground cables, radar installations, other metal detectors, or natural electrical events such as lightning storms. It produces electrical signals that can interfere with a detector's operation, causing false target responses or threshold instability.
See also: EMI, Falsing, Noise Cancel
F
Falsing
Falsing is a false detection response produced in the absence of a genuine metal target. Common causes include electromagnetic interference, poorly compensated ground mineralisation, physical bumping or knocking of the search coil, and highly mineralised hot rocks. Reducing sensitivity, improving ground balance, and using noise cancel reduces falsing.
FBS (Full Band Spectrum)
FBS is an advanced multi-frequency technology that simultaneously transmits, receives, and analyses a full band of frequencies, providing even more target and ground information than BBS. Key advantages include:
- High sensitivity across a wide range of target types and sizes
- Automatic ground compensation for maximum depth even in mineralised and saltwater beach conditions
- Precise separation of target signals from ground signals
- Two-dimensional Smartfind discrimination for simultaneous ferrous and conductivity classification
See also: BBS, Multi-frequency
Learn more: Metal Detector Technologies Explained|Shop Multi-Frequency Detectors
FE (Ferrous)
FE is the abbreviation for the ferrous axis on two-dimensional discrimination displays. A high FE value indicates the target contains significant iron content. Combined with the CO (conductivity) value, FE enables more precise target identification than single-axis systems.
Ferrous
Ferrous describes materials that contain iron and are therefore attracted to a magnet. Most ferrous targets found while detecting are junk (nails, bolts, wire, cans), though corroded iron artefacts can have significant historical value. Ferrous targets typically produce low, negative, or unstable target IDs on most detectors.
See also: Non-ferrous, Iron Mask
Frequency
The frequency of a metal detector is the number of complete signal cycles transmitted per second, measured in hertz (Hz) or kilohertz (kHz). Frequency is one of the most important performance characteristics:
- Low frequency (below ~10 kHz): deeper penetration, better on large high-conductivity targets (silver coins, large gold), reduced sensitivity to small targets
- High frequency (above ~15 kHz): greater sensitivity to small low-conductivity targets (fine gold, thin jewellery), reduced depth on large targets
- Multi-frequency: simultaneously combines the benefits of low and high frequencies
See also: VLF, Multi-frequency, BBS
Learn more: Metal Detector Technologies Explained|How Do Metal Detectors Work?
Frequency Domain
The frequency domain is a way of viewing or analysing a signal by plotting its energy against frequency rather than against time. Viewing a signal in the frequency domain reveals its fundamental frequency and all harmonic components, which is useful for understanding EMI sources and detector behaviour.
See also: Time Domain, Harmonic Frequencies
Finds Pouch / Belt Pouch
A finds pouch is a bag worn on the belt or clipped to clothing to hold recovered targets during a detecting session. Most detectorists use a two-compartment pouch — one side for keepers (coins, jewellery, interesting items) and one side for junk to be disposed of responsibly. A good finds pouch keeps hands free, prevents losses in long grass, and avoids mixing good finds with trash.
G
GeoZVT
Minelab's next-generation evolution of ZVT (Zero Voltage Transmission), introduced in the GPZ 8000. GeoZVT builds on ZVT's depth and small-gold sensitivity by adding enhanced ground signal processing, improved rejection of highly mineralised and conductive soils, and better EMI handling in challenging field environments. The result is greater usable depth in the difficult ground conditions common to serious gold prospecting — deeply weathered laterite, wet salt, and heavy ferrite mineralisation — without sacrificing sensitivity to fine or deeply buried nuggets. See also: ZVT, Pulse Induction.
Gold Prospecting
Gold prospecting is detecting specifically aimed at finding natural gold — nuggets, flakes, or specimens — in mineralised soils and creek beds. Gold prospecting detectors require superior ground balance capability to handle highly mineralised (often iron-rich) soils, high transmit frequency or PI technology for sensitivity to small low-conductivity gold, and robust weatherproof construction for use in remote terrain.
See also: Coin, Jewellery & Relic Hunting, Pulse Induction
Shop: Gold Metal Detectors|Gold Prospecting Equipment|Best Gold Detectors Guide
Ground Balance
Ground balance is a calibration setting that cancels the electromagnetic response from mineralised soil so that only genuine metal targets produce a signal. Without correct ground balance, soil minerals cause continuous false signals that mask real targets.
Three main types:
- Manual — operator adjusts a control until ground noise is minimised
- Automatic (single-point) — detector samples the ground and sets the correct value automatically
- Tracking — detector continuously resamples and adjusts as ground conditions change
See also: Ground Mineralisation, Ground Tracking, ACCU-TRAK
Learn more: How Do Metal Detectors Work?
Ground Mineralisation
Ground mineralisation refers to naturally occurring minerals in the soil that respond to a detector's electromagnetic field in a way that mimics metal targets. Two main types:
- Iron mineralisation — fine iron oxide particles (common in red soils) make the ground magnetically responsive
- Salt mineralisation — dissolved salts (common on wet beaches) make the ground electrically conductive
Both types can produce false signals and reduce detection depth if not compensated by a proper ground balance setting.
Ground Noise
Ground noise is the erratic false signalling produced when a detector is not properly ground-balanced for the soil. As the coil sweeps over variations in mineralisation, soil type, or terrain irregularities, the uncompensated ground signal produces random audio responses and unstable target IDs.
Ground Phase
Ground phase is a numeric value representing the phase angle of the eddy currents induced in the soil by the detector's transmitted field — not the shift of the transmitted signal itself. It is used internally by the detector to set the correct ground balance compensation point. Many auto-ground-balance detectors display the ground phase reading, which gives the operator useful information about soil type and mineralisation level.
See also: Ground Balance
Ground Tracking
Ground tracking is a continuous automatic ground balance mode in which the detector constantly resamples the soil and adjusts its ground balance compensation as the coil is swept. It eliminates the need to stop and re-balance as soil conditions change, ensuring consistent performance across varying terrain.
See also: Ground Balance, ACCU-TRAK
Gold Pan
A gold pan is a shallow, wide circular pan — typically plastic in modern use — used to separate gold from gravel and sand using water. The pan's angled inner ridges (riffles) assist in retaining dense gold particles, though the primary separation mechanism is the swirling motion and the high specific gravity of gold — many effective pans have minimal riffles and rely primarily on technique. Gold pans come in various sizes (10–16 inches is common) and colours — dark green or black provide the best contrast for spotting fine gold flakes and small nuggets. Gold panning is one of the oldest and most accessible forms of gold prospecting.
See also: Gold Panning, Riffle, Classifier
Gold Panning
Gold panning is the process of using a gold pan and water to separate alluvial (water-deposited) gold from gravel, sand, and lighter mineral material. Material is loaded into the pan, submerged, and agitated with a swirling motion that causes the heavier gold to sink to the bottom while lighter material washes off. The process is repeated progressively until only the densest concentrate remains, which is then carefully inspected for gold. Panning requires no power, is highly portable, and is an excellent tool for sampling an area before setting up larger equipment like a sluice or highbanker.
See also: Gold Pan, Classifier, Sluice Box, Gold Prospecting
H
Halo Effect
The halo effect occurs when a target has been buried undisturbed for an extended period. Minerals leached from the corroding target migrate into the surrounding soil, creating a zone of elevated mineralisation. The detector responds to this larger mineralised area rather than the object itself, producing a stronger and wider signal than the target's actual size would normally generate — and sometimes making a deeply buried target easier to detect than a freshly buried one of the same size.
Harmonic Frequencies
Harmonic frequencies are frequency components at integer multiples of a fundamental frequency. A 15 kHz signal has harmonics at 30, 45, 60 kHz, and so on, diminishing in amplitude with each step. Square waves are rich in harmonics, while pure sine waves produce none. Harmonic emissions from external equipment can coincide with a detector's operating frequency and cause interference.
See also: Frequency Domain, EMI
Hot Rocks
Hot rocks are rocks with a mineralisation level significantly different from the surrounding soil matrix. A highly mineralised rock in mildly mineralised soil will produce a false signal because the detector's ground balance is set for the background soil, not the rock. Hot rocks are common in gold prospecting areas and are a major source of falsing for PI detectors without good ground compensation.
See also: Ground Mineralisation, Falsing
Headphones
Headphones allow the detectorist to hear audio target signals clearly without disturbing others nearby, and improve signal audibility in windy conditions. Wired headphones connect directly to the detector's audio jack. Wireless (Bluetooth) headphones eliminate the cable entirely — a significant advantage in the field — and are standard on platforms like the XP DEUS II where the whole system is cable-free. Key specifications include connector compatibility (¼ inch, ⅛ inch, or proprietary), volume sensitivity, and whether the headphones are waterproof for beach or water detecting use. Impedance matching — a consideration on older detectors — is not a significant practical concern on modern machines, which work well with a wide range of consumer headphone impedances.
See also: Ohm, Tone Identification
Highbanker
A highbanker (also called a power sluice) is a sluice box elevated on legs and fed with water via a pump and hose, allowing prospecting away from a natural water source. The pump draws water from a bucket or nearby water source and pumps it through the sluice, washing material across the riffles and matting to capture gold. Highbankers process significantly more material per hour than hand panning and are a practical step up for prospectors working dry or semi-dry locations. Most systems are modular — the sluice box itself can often be detached and used directly in a stream without the elevated frame.
See also: Sluice Box, Riffle, Classifier
I
Iron Bias
Iron bias is a setting that controls how strongly the detector weighs ferrous (iron) indicators when a target produces a mixed or ambiguous response — for example, a corroded iron object or a non-ferrous target lying close to iron junk. Higher iron bias causes the detector to classify borderline signals as iron more readily, reducing false non-ferrous IDs on junk at the cost of occasionally masking genuinely good targets near iron.
See also: Discrimination, Target Masking
Iron Mask
Iron mask is an operating mode in which the detector discriminates out ferrous targets, producing a response only to non-ferrous or low-iron objects. Widely used in gold prospecting to ignore iron junk such as nails and wire, allowing the operator to focus on non-ferrous gold signals.
See also: Discrimination, Ferrous
J
Junk / Trash
Junk (also called trash) refers to unwanted metal targets in the ground. Ferrous junk includes nails, screws, wire, and tin cans. Non-ferrous junk includes aluminium foil, ring pulls, bottle caps, and lead fragments. Junk is typically far more abundant than desirable targets and is the primary reason discrimination settings exist. In highly trashy ground, even good target signals can be masked by nearby junk.
See also: Discrimination, Trashy Ground, Target Masking
L
Li-ion Battery (Lithium-Ion)
Lithium-ion batteries are rechargeable batteries that offer significant advantages over older technologies: higher energy density (more capacity for less weight), no memory effect, and very low self-discharge rates. Increasingly the standard in modern metal detectors, often integrated as non-removable packs with USB charging.
See also: NiMH, NiCd, SLA Battery
Shop: Metal Detector Batteries
M
Monoloop Coil
A Monoloop coil uses a single winding around the coil's circumference that acts as both the transmit and receive antenna. Used primarily on Pulse Induction detectors, it produces a cone-shaped detection field requiring greater sweep overlap than a Double-D coil. In heavily mineralised ground, the monoloop's simpler single-winding field design can deliver marginal depth advantages. In moderate mineralisation, Double-D coils are typically comparable or superior due to their better inherent ground rejection. Monoloop coils can be harder to ground-balance in the most extreme mineralisation.
See also: Double-D Coil, Concentric Coil, MPS
Shop: Search Coils|Learn more: Understanding Metal Detector Coils
MPS (Multi Period Sensing)
MPS (Multi Period Sensing) is an advanced Pulse Induction technology that transmits pulses of different time periods and samples the received signal at multiple corresponding time windows. By comparing responses across different periods, the electronics can isolate and remove the ground mineralisation signal while retaining target signals — delivering superior depth in extremely mineralised soils.
See also: DVT, Pulse Induction
Learn more: Metal Detector Technologies Explained
Multi-frequency
Multi-frequency technology transmits and processes more than one frequency simultaneously. Because lower frequencies offer deeper penetration and higher frequencies offer better sensitivity to small targets, a multi-frequency detector simultaneously achieves both — outperforming any single operating frequency for the widest range of detecting conditions and target types.
Shop: Multi-Frequency Metal Detectors|Learn more: Metal Detector Technologies Explained
Multi-IQ
Minelab's simultaneous multi-frequency platform, used in the Equinox and Vanquish series. Unlike switchable multi-frequency systems (which run one frequency at a time), Multi-IQ transmits, receives, and processes multiple frequencies concurrently. This gives target ID accuracy at depth that no single-frequency detector can match, because each frequency contributes phase and conductivity data independently — the processor then combines them into a single stable target ID readout. Multi-IQ also handles salt beach conditions and mineralised soil better than single-frequency VLF, since the simultaneous processing can separate ground noise from target signal more effectively. See also: VLF, BBS, FBS, Multi-IQ+.
Multi-IQ+
The enhanced version of Multi-IQ used in the Minelab Manticore. Multi-IQ+ transmits more power through the coil and uses revamped signal processing for higher target ID resolution and improved discrimination — particularly useful for separating low-conductivity targets (hammered silver, fine gold) from iron in dense trash. Where standard Multi-IQ gives a single-axis target ID, Manticore's Multi-IQ+ produces a two-dimensional target ID plot (iron probability on one axis, conductivity on the other), giving significantly more information per signal. See also: Multi-IQ, SmartFind.
N
NiCd Battery (Nickel-Cadmium)
Nickel-cadmium batteries are rechargeable cells at 1.2 V with good high-drain performance. However, they suffer from memory effect — capacity degrades if consistently recharged before fully discharged — and have a relatively high self-discharge rate. Largely superseded by NiMH and Li-ion technologies in modern detector designs.
NiMH Battery (Nickel-Metal Hydride)
Nickel-metal hydride batteries are rechargeable cells at 1.2 V per cell that offer higher energy density than NiCd without the memory effect problem. Available in standard AA sizes, making them a practical rechargeable replacement for alkaline cells in AA-powered detectors.
Shop: Metal Detector Batteries
Noise Cancel
Noise Cancel scans available operating channels or frequencies and selects the one least affected by electromagnetic interference from power lines, towers, or nearby detectors. The process typically takes a few seconds and should be run at the start of each detecting session or when entering a new location.
Non-ferrous
Non-ferrous materials contain no iron and are not attracted to a magnet. Desirable non-ferrous targets include gold, silver, copper, and bronze. Non-ferrous junk includes aluminium foil, pull tabs, and lead. Non-ferrous targets typically produce stable, positive target IDs on most detectors.
See also: Ferrous
Notch Filter Discrimination
Notch filter discrimination accepts or rejects a specific narrow band of target IDs on the conductivity scale. For example, a notch can be set to reject the pull-tab target ID range while accepting coins of similar conductivity either side of it — though in practice, overlap between pull-tab and ring IDs makes precise notching challenging.
See also: Discrimination
O
Ohm
The ohm (symbol Ω) is the SI unit of electrical resistance. In metal detecting, ohm ratings appear primarily in headphone and speaker specifications. Impedance-matched headphones help the detector's audio circuit operate efficiently.
See also: Resistance, Current, Voltage
P
Period
The period is the time required for one complete cycle of a wave, equal to the reciprocal of frequency: period = 1 ÷ frequency. A 10 kHz signal has a period of 0.1 milliseconds (100 microseconds). Relevant in PI detectors where pulse timing (measured in microseconds) directly affects performance characteristics.
Pinpointing
Pinpointing is the process of locating the exact position of a buried target before digging. Most detectors offer a dedicated pinpoint mode. The technique involves entering pinpoint mode over the signal, making a slow sweep to find the peak response, then rotating 90° and sweeping again. Where the two peaks intersect is directly above the target.
See also: Pinpointer (Probe)
Pinpointer / Probe
A pinpointer is a handheld probe-shaped secondary detector used inside the excavated hole to find the exact location of a target within loose soil or debris. Without a pinpointer, recovery can involve extensive searching through soil by hand. Most pinpointers vibrate and/or emit a tone that increases in intensity as the probe approaches the target.
See also: Pinpointing
Pulse Induction (PI)
Pulse Induction is a metal detecting technology that operates by transmitting short, powerful bursts (pulses) of voltage to the search coil, generating a brief magnetic field that collapses rapidly at the end of each pulse. Any metal target nearby retains residual magnetism for a short period after the pulse ends. This decaying magnetism is detected by the coil in the quiet period between pulses.
PI detectors excel in highly mineralised soils and saltwater environments where VLF detectors struggle. Early PI designs offered limited discrimination, but modern PI technologies (MPS, DVT) have largely closed that gap — high-end PI detectors now match or exceed VLF discrimination accuracy in many conditions.
Learn more: Metal Detector Technologies Explained|How Do Metal Detectors Work?
Q
QuickMask
QuickMask is a feature available on certain advanced detectors that provides rapid access to edit and customise the active discrimination pattern without navigating through the full menu system, allowing fast on-the-fly adjustments when site conditions change.
See also: Discrimination Pattern
R
Receive (RX)
The receive function is the process by which the search coil's receive winding picks up the secondary electromagnetic field generated by a target's eddy currents. The receive circuit amplifies this tiny signal and passes it to the detector's processing electronics for analysis.
See also: Transmit (TX), Eddy Currents
Recovery Speed
Recovery speed is how quickly a detector's circuitry resets between consecutive targets and becomes ready to respond to a new signal. In trashy ground, fast recovery speed is critical: a slow-recovering detector may still be processing the response from a nearby iron nail when the coil passes over a coin, causing the coin to be missed entirely. Higher recovery speed generally comes with a slight reduction in depth on single targets.
See also: Target Masking, Trashy Ground
Resistance
Resistance is the opposition to electrical current flow in a conductor, measured in ohms (Ω). In metal detecting, resistance is the inverse of conductivity — low resistance targets are highly conductive and produce high target IDs; high resistance targets are poorly conductive and produce low IDs.
See also: Conductivity, Ohm
Riffle
Riffles are the raised ridges or bars on the floor of a sluice box, gold pan, or recovery mat that create turbulent eddies in the water flow. These eddies cause dense heavy minerals — including gold — to drop out of suspension and settle behind the riffles, while lighter material continues downstream. Riffle design (height, spacing, shape) significantly affects gold recovery efficiency. Shallow riffles work better for fine gold; deeper riffles handle coarser material. Most modern sluice mats combine rubber riffles with textured backing matting to maximise fine gold capture.
See also: Sluice Box, Gold Pan, Concentrator
S
Search Coil (Loop / Head)
The search coil is the circular or elliptical housing swept above the ground during detecting. It contains the transmit (TX) and receive (RX) wire windings. The coil transmits the electromagnetic field into the ground and receives the response signals from targets. Coil size affects both depth and sensitivity: larger coils cover more ground and reach deeper but are less sensitive to small targets; smaller coils are better for small targets and trashy ground.
See also: Concentric Coil, Double-D Coil, Monoloop Coil
Shop: Search Coils|Learn more: Understanding Metal Detector Coils
Sensitivity
Sensitivity is a user-adjustable control governing how responsive the detector is to small or faint signals. Higher sensitivity increases depth and small-target detection ability but also amplifies responses to ground mineralisation and EMI, increasing falsing and ground noise. Optimal sensitivity is the highest stable setting for the conditions — typically below maximum in mineralised soil.
SETA (Smart Electronic Timing Alignment)
SETA is an advanced timing technology that matches each individual timing's characteristics with continuous measurements from the surrounding electromagnetic environment, including the earth's magnetic field. The result is complete removal of noise across all timing settings, increasing sensitivity and detection ability across all operating conditions.
Learn more: Metal Detector Technologies Explained
Signal
In metal detecting, signal refers both to the transmitted electromagnetic field from the search coil and to the received electromagnetic response from a metal target. Detectors convert the received signal into an audio tone and/or a visual target ID for the operator to interpret.
Sine Wave
A sine wave is a smooth, continuously curving waveform that mathematically follows the sine function. VLF metal detectors transmit a pure or near-pure sine wave. Unlike square waves, pure sine waves produce no harmonic frequency components, making them less likely to cause interference with other equipment operating at those harmonic frequencies.
See also: Square Wave, Continuous Wave
SLA Battery (Sealed Lead-Acid)
Sealed lead-acid batteries are rechargeable batteries packaged in 6 V or 12 V packs. They offer low internal resistance and high discharge current capability, making them suitable for high-power detector designs. The main disadvantage is weight — SLA batteries are significantly heavier than NiMH or Li-ion alternatives of equivalent capacity.
Shop: Metal Detector Batteries
Smartfind
Smartfind is a two-dimensional discrimination display that plots both a target's ferrous (FE) content and its conductivity (CO) value simultaneously on a single screen. This provides far more target identification information than one-dimensional target ID systems, allowing the operator to make more informed digging decisions — for example, distinguishing a gold ring from a pull-tab at a similar conductivity level by their different ferrous characteristics.
See also: Discrimination, CO, FE
Square Wave
A square wave is a waveform that transitions rapidly between two voltage states. Used extensively in digital electronics for clocking and control signals. Square waves generate many harmonic frequencies — relevant in metal detecting when external equipment producing square wave signals radiates harmonics at the detector's operating frequency.
See also: Sine Wave, Harmonic Frequencies
Sweep Speed
Sweep speed is the rate at which the search coil is moved across the ground. Most VLF detectors require a consistent, moderately slow sweep (roughly 1 metre per second) to process target signals fully. Sweeping too fast can cause the processor to miss short time-constant targets or reduce depth; sweeping too slowly on some designs can cause threshold instability. PI detectors are generally more tolerant of variable sweep speeds.
Sand Scoop
A sand scoop is a perforated metal or plastic scoop used to retrieve detected targets from beach sand or shallow water. The holes allow wet sand to drain quickly while retaining the target. Scoops come in various sizes and hole patterns — smaller holes for fine gold and jewellery, larger holes for coins in coarse sand. Long-handled scoops let the detectorist retrieve targets from waist-deep water without having to crouch. Material matters: stainless steel handles salt and abrasion better than aluminium over long periods; plastic is lighter for dry sand use.
See also: Pinpointing, Pinpointer
Shaft / Stem
The shaft (also called the stem or rod) is the telescoping pole that connects the search coil to the control box and provides the arm support structure of the detector. Most shafts consist of an upper section (which typically incorporates an S-bend elbow), a lower rod, and a camlock or twist-lock adjustment mechanism, telescoping to fit the detectorist's height. Shaft material affects overall detector weight and balance: standard shafts are fibreglass or aluminium; aftermarket carbon fibre shafts are significantly lighter and stiffer, reducing arm fatigue on long sessions. The lower rod attaches directly to the search coil and takes most of the wear, so replacement lower rods are a common accessory purchase.
See also: Arm Cuff, Control Box, Search Coil
Shop: Detector Shafts & Rods
Sluice Box
A sluice box is a long trough placed in a stream or fed by a pump, through which water carries gold-bearing gravel. The current washes lighter material over a series of riffles and matting on the sluice floor, while the weight of gold causes it to drop and be trapped. Sluice boxes process far more material than hand panning — larger pump-fed setups can handle hundreds of kilograms per hour, while a typical portable sluice hand-fed by one person will process considerably less. Key variables are water flow rate, angle of incline, riffle design, and backing mat texture. After a run, the sluice is cleaned out and the concentrated material from the riffles is panned to recover the gold.
See also: Riffle, Highbanker, Classifier, Gold Panning
Snifter Bottle / Sniffer Bottle
A snifter bottle (also called a sniffer or sucker bottle) is a small squeeze bottle with a narrow tip used to suck up fine gold particles, flakes, or small nuggets from a gold pan, crevice, or tray. The tip is placed over the gold and the bottle is squeezed then released, creating suction that draws the gold inside. An essential tool for recovering fine gold that is too small to pick up by hand without losing it, and for clearing gold from tight bedrock crevices.
See also: Gold Panning, Gold Prospecting
Specimen Vial
A specimen vial is a small glass or plastic tube with a tight-fitting cap used to store and display recovered gold — flakes, fine gold dust, or small nuggets. Glass vials are preferred over plastic for their optical clarity and scratch resistance — soft plastics can cloud over time, making fine gold harder to see. Vials are typically carried in the field to safely store gold as it is recovered rather than risking losing fine particles in a pocket or pouch.
See also: Snifter Bottle, Gold Panning
T
Target
A target is any metal object detectable by a metal detector. Targets can be desirable (coins, jewellery, gold, historical artefacts) or undesirable junk (nails, foil, bottle caps). The entire workflow of metal detecting — discrimination, target ID, and pinpointing — is oriented around distinguishing desirable targets from junk before committing to a dig.
Target ID
A Target ID is a numerical value assigned by the detector's electronics to represent a target's conductive and ferrous properties. IDs allow the operator to estimate the probable target type before digging. Different detector brands use different ID scales, but generally higher numbers indicate more conductive (e.g. silver) targets and lower numbers indicate less conductive or ferrous targets.
| Target | Typical Target ID |
|---|---|
| US Quarter (silver) | ~75–80 |
| US Penny (zinc) | ~65–72 |
| Gold ring (10k) | ~20–45 (varies by size/karat) |
| Aluminium pull tab | ~35–55 |
| Bottle cap (steel) | ~40–60 (variable) |
| Iron nail | ~−10 to 10 |
Note: ID numbers vary significantly between detector brands and models. Always refer to your specific detector's ID chart.
Target Masking
Target masking occurs when the signal from one metal object — typically a large iron target — overwhelms or cancels out the response from a nearby desirable target, making the good target effectively undetectable. It is one of the primary reasons valuable finds are missed in trashy ground. Using a small coil, increasing recovery speed, and slowing sweep speed all help reduce masking effects.
See also: Recovery Speed, Trashy Ground
Threshold
The threshold is a continuous low-level audio tone used as a baseline reference. Changes in threshold — a dip (null) indicating a discriminated target, or a rise indicating a non-discriminated one — provide additional information beyond the main target signal. The threshold is essential for all-metal and PI detecting, where subtle threshold variations are the primary detection signal.
Time Constant
The time constant measures how long eddy currents persist in a target after the transmit field is removed. It is determined by the target's combined conductivity and inductance. High conductivity + high inductance = long time constant (e.g. a large gold bar). Low conductivity + low inductance = short time constant (e.g. a fine gold chain). PI detectors using MPS technology exploit differences in time constants to separate target signals from ground mineralisation signals.
See also: Conductivity, Eddy Currents
Time Domain
The time domain is the standard way of viewing a signal as it changes over time — a plot of voltage (or amplitude) versus time. PI detectors operate primarily in the time domain, sampling received signals at specific microsecond intervals after each transmitted pulse to distinguish between target responses and ground responses by their differing decay times.
See also: Frequency Domain, Pulse Induction
Timings
On Pulse Induction detectors, timings are selectable presets that control the pulse duration, inter-pulse delay, and receive sampling window of the transmit/receive cycle. Different timing settings optimise performance for specific ground mineralisation levels and target types — for example, some timings are better suited to saltwater beach sand, others to deep, heavily mineralised red earth.
Tone Identification
Tone identification assigns different audio tones to different target ID ranges, allowing the operator to classify probable target types by ear without looking at the display. More tones (some detectors offer 4, 8, or even continuous variable pitch) give more precise audio feedback but require more experience to interpret reliably. Many experienced detectorists rely primarily on tone ID rather than numeric displays.
Transmit (TX)
The transmit function is the process by which the detector's electronics drive an alternating current through the search coil's transmit winding, generating the electromagnetic field that extends into the ground and induces eddy currents in any nearby metal targets.
See also: Receive (RX), Electromagnetic Field
Trashy Ground
Trashy ground is soil containing a high density of junk targets. Parks, beaches, picnic areas, and old farmland are commonly trashy. Detecting in trashy ground requires careful discrimination settings, fast recovery speed, small coils to reduce the chances of multiple targets in the detection field simultaneously, and a slower sweep speed to ensure each target gets a clean read.
See also: Junk, Recovery Speed, Target Masking
Trommel
A trommel is a motorised rotating cylindrical drum with a mesh screen that classifies raw material by size as it tumbles through. Water is sprayed inside the drum to break up clumps and wash material through the screen holes, separating fine gold-bearing material from coarser rock and gravel. The fines drop onto a sluice or mat below for gold recovery. Trommels are faster and more automated than hand classifying, making them practical for processing high volumes of material at fixed or semi-permanent prospecting sites.
See also: Classifier, Sluice Box, Highbanker
U
USB Port (Universal Serial Bus)
A USB port on a metal detector's control box enables communication with a computer for firmware updates, settings backup and transfer, and uploading or downloading custom discrimination patterns. Some modern detectors also use USB-C for battery charging.
V
VFLEX
VFLEX is a single-frequency VLF technology using advanced digital electronics to deliver improved stability and enhanced immunity to outside electromagnetic interference compared to earlier analogue VLF designs. A particularly useful feature is frequency agility: swapping to a different VFLEX-compatible coil automatically changes the detector's operating frequency to match the coil's design frequency, allowing a single detector body to effectively operate at multiple frequencies by changing coils.
Learn more: Metal Detector Technologies Explained
VLF (Very Low Frequency)
VLF is the most widespread category of metal detecting technology, transmitting a continuous sine-wave electromagnetic field at frequencies typically between 3 kHz and 100 kHz. VLF detectors offer good discrimination capabilities and target ID accuracy. Their main limitation is performance in highly mineralised soil, where Pulse Induction technology generally excels.
See also: Continuous Wave, Pulse Induction, VFLEX
Learn more: Metal Detector Technologies Explained|How Do Metal Detectors Work?
Voltage
Voltage is electrical potential difference, measured in volts (V). Battery voltage powers the detector's transmit circuitry; higher transmit voltage generally enables deeper electromagnetic field penetration. Battery voltage is also relevant to runtime — alkaline AA cells start at 1.5 V and drop gradually, while NiMH cells deliver a stable 1.2 V until nearly depleted.
See also: Current, Resistance
Z
ZVT (Zero Voltage Transmission)
A Minelab-proprietary transmission technology developed for deep gold detection in heavily mineralised ground. Standard Pulse Induction detectors transmit a rectangular pulse and must wait for two things before listening: the coil's own switching transient (flyback) to decay, and the ground's induced response to settle — delays that together create a blanking period during which small, shallow targets are missed. ZVT transmits a specially shaped waveform engineered to produce a minimal ground response at the transmit-to-receive transition, effectively nulling the ground's contribution at that moment. This allows the receive window to open significantly earlier than in conventional PI, recovering sensitivity to small and shallow nuggets that would otherwise be lost in the blanking period. The result is a system that combines the mineralised-ground depth of PI with sensitivity to fine gold that approaches VLF — a trade-off no previous technology achieved cleanly. Used in the Minelab GPZ 7000; evolved into GeoZVT in the GPZ 8000. See also: Pulse Induction, GeoZVT, MPS.