Metal Detector Technologies

VFLEX Technology

VFLEX uses state of the art digital electronics and signal processing to enhance conventional single frequency (VLF) metal detector technology. VFLEX provides increased detecting performance with perfect sine wave transmission, an in-coil signal booster and coil selectable transmit frequencies.

 

World's First All-Digital Metal Detectors

VFLEX transforms conventional single frequency metal detection technology by including two microcontrollers (miniature computers), one inside the control box and one inside the coil. Every time the detector starts up, the microcontrollers establish communication via a digital data link. The coil microcontroller communicates the coil’s configuration, size and exact frequency, so the control box can generate a perfectly matched transmit signal. This significantly reduces distortion and increases Target ID accuracy.

 

Perfect Sine Wave Transmission

VFLEX technology generates and transmits a perfect high quality sine wave, using the same technology that is found in high quality digital audio players, and is produced without distortion. The removal of distortion maximises power transmitted from the coil, therefore increasing detection depth and sensitivity. This also results in enhanced Target ID accuracy and greater immunity to both ground and environmental noise.

 

In-Coil Signal Booster

Weak target signals are amplified inside the coil, before the receive signal is sent up the coil cable where interference and signal loss can occur. This technique improves immunity to electrical noise by reducing false signals and increasing target signal strength, therefore improving detection depth and sensitivity.

 

Coil Selectable Transmit Frequencies

By changing the coil you can change the detector’s frequency, maximising sensitivity and depth for a wide range of target types and conditions. VFLEX gives you three frequencies to choose from: 3 kHz, 7.5 kHz and 18.75 kHz.
    CONCENTRIC 3kHz
    • Low frequency for deep, large and/or high conductive targets, such as silver, copper, large gold rings and relics
    DOUBLE D/CONCENTRIC 7.5kHz
    • Medium frequency for all-round detecting, good sensitivity and detection depth for all target sizes
    DOUBLE D/CONCENTRIC 18.75kHz
    • High frequency is very sensitive and ideal for jewellery, fine chains and sub-gram gold nuggets

 

BROAD BAND SPECTRUM (BBS)

BBS (Broad Band Spectrum) simultaneously transmits, receives and analyses a broad band of multiple frequencies to deliver substantial detection depth, high sensitivity and accurate discrimination for a wide range of target types. This broad band of frequencies provides the detector’s electronics with more information about a target and the surrounding environment than is possible with single frequency technologies. The detector carries out advanced signal processing of these frequencies resulting in improved target identification accuracy and increased depth. This process also significantly reduces false signals from ground minerals, even in harsh and variable conditions, such as salt water beaches.

 

Find Different Target Types & Sizes with Every Sweep

Generally, high transmit frequencies are more sensitive to small targets and low transmit frequencies give more depth on large deep targets. BBS simultaneously transmits and analyses a broad band of multiple frequencies from 1.5 kHz to 25.5 kHz and is therefore sensitive to both small and large deep targets at the same time. This means you only need to cover the ground once, allowing you to find more treasure.

 

In-Coil Signal Boostersinewave-X-Terra-1

RCB (Receive Coil Boost) circuitry greatly amplifies weak target signals, from small and deep targets, inside the search coil, where the signals are received. This has three main advantages over standard techniques of amplification inside the control box:

  1. Greater immunity to electrical noise, reducing false signals
  2. No loss of signal strength, and faint targets, through the cable
  3. Improved detection depth and sensitivity

 

Accurate Multi-Channel Signal Conversion

BBS analyses multiple signal channels through a technique called multiplexing (MUX). These signals are compared to a digital reference (Vref. and DAC). The end result is high resolution accurate target signals that can be identified by the detector’s microcontroller (MCU). This analogue-to-digital conversion technique allows BBS to separate ground signals from target signals, achieving great depth and stability in difficult conditions.

 

FULL BAND SPECTRUM (FBS)

FBS (Full Band Spectrum) simultaneously transmits, receives and analyses a full band of multiple frequencies. This provides the detector’s electronics with even more information about a target and the surrounding environment than is possible with single frequency or BBS technology. This has a number of advantages, including:

  • High sensitivity across a wide range of target types and sizes, so you only have to cover the ground once.
  • Automatic sensitivity and ground compensation, so maximum depth is achieved even in mineralised ground, including salt water beaches.
  • Extremely accurate multi-channel signal conversion to precisely separate target signals from ground signals for maximum detection depth and high resolution target identification.
  • Smartfind two dimensional discrimination, giving you maximum target information, so that targets can be discriminated by both ferrous and conductive properties simultaneously

 

Find Every Target Type & Size with Every Sweep

Generally, high transmit frequencies are more sensitive to small targets and low transmit frequencies give more depth on large deep targets. FBS simultaneously transmits and analyses a full band of multiple frequencies from 1.5 kHz to 100 kHz and is therefore sensitive to both very small and large deep targets at the same time. This means you only need to cover the ground once and can be confident you’re not leaving ANY valuable treasure behind.

 

Automatic Sensitivity & Ground Compensation for Maximum Depth

As you sweep the coil in search of targets, Automatic Sensitivity and Ground Compensation monitor the full band of frequencies for changes in ground mineralisation. Whenever the level of ground mineralisation changes the sensitivity is automatically adjusted to maintain maximum depth. The ground compensation circuitry removes false signals caused by fast changing levels of ground mineralisation. Both of these advanced features work together to maintain maximum detection depth and sensitivity, allowing you to concentrate on listening for targets.

 

Extremely Accurate Multi-Channel Signal Conversion

FBS uses multiple channelled Sigma-Delta analogue-to-digital converter technology to digitise the analogue signals received by the search coil. This ultra-fast processing, using a digital reference (1 bit DAC), provides the microcontroller (MCU) with detailed information about the ground conditions and targets. This gives FBS the ability to precisely separate target signals from ground signals for maximum detection depth. It also provides Smartfind with the necessary high resolution target data to accurately plot targets.

 

MULTI PERIOD SENSING (MPS)

MPS (Multi Period Sensing) is Minelab’s advanced Pulse Induction (PI) technology that transmits pulses of different time periods. MPS also samples the receive signal at multiple time periods allowing target signals and ground signals to be separated. This effectively removes the ground signal from even the most highly mineralised ground while still being sensitive to both small and deep gold. This achieves superior depth in extremely mineralised ground.

 

DUAL VOLTAGE TECHNOLOGY (DVT)

DVT (Dual Voltage Technology) is Minelab’s advanced Pulse Induction technology that uses pulses with two voltage levels to further enhance MPS. The two voltage levels work in combination with the different time period pulses transmitted by MPS to increase the amount of power transmitted into the ground. DVT also allows more of the ground signal to be removed, further increasing detection depth and sensitivity. This achieves ultimate depth in extremely mineralised ground.

 

SMART ELECTRONIC TIMING ALIGNMENT

SETA (Smart Electronic Timing Alignment) is a highly complex method of matching the characteristics of individual Timings with continuous measurements from the surrounding electromagnetic environment, such as the earth’s magnetic field. This gives the advantage of improved detector performance through the complete removal of noise signals. The sensitivity across all Timings is increased, therefore SETA allows more gold to be found than any other metal detector technology.

 

CONTINUOUS SINE WAVE (VLF)

VLF (Very Low Frequency) is a conventional single frequency sine wave transmission technology. This is the traditional type of technology used in most basic metal detectors. Single frequency sine wave detectors create an electro-magnetic field, which is transmitted into the ground in a continuous wave. While the basic way that the signal is sent out and received back has not changed, the receive signal processing has improved enormously. This has proven to be a reliable and easy to use technology for finding gold.

 

SELECTABLE THREE FREQUENCY TRANSMISSION

3F (Three Frequency) provides three different transmit frequencies in the one metal detector, selectable at the flick of a switch. Each transmit frequency optimises the detector for different size targets and conditions. The three transmit frequencies are:

  • 6.4 kHz – Best for large deep gold nuggets
  • 20 kHz – Best for general gold detecting
  • 60 kHz – Best for small gold nuggets

Having three selectable frequencies gives the versatility that is equivalent to three conventional single frequency detectors.

 

ACCU-TRAK

ACCU-TRAK continuously measures the level of ground mineralisation while the detector’s coil is swept in search of targets. Any changes in mineralisation, which can occur quite quickly, are analysed and the Ground Balance level automatically adjusted.

ACCU-TRAK ensures the detector is always correctly ground balanced and operating at maximum depth and sensitivity at all times with minimum effort. (Sovereign GT is the only TREASURE detector with ACCU TRAK).

 

SEARCH COIL SIZE

The size of a coil can influence the detection depth and sensitivity of a detector. The larger the coil, the deeper it tends to detect, but with less sensitivity to small targets. The smaller the diameter, the more sensitive it becomes, but with reduced detection depth.

Smaller coils are lighter in weight, easier to control and may be chosen for their ability to negotiate difficult terrain or undergrowth. Smaller coils also have a target separation advantage in areas of high trash, due to their smaller detection footprint.

 

AUTOMATIC GROUND TRACKING

Ground tracking refers to the ability of the detector to track changes in ground mineralisation and automatically adjust the ground balance to suit. This ensures perfect ground balance and maximum detection depth, eliminating the need for the operator to stop and manually adjust the detector as ground conditions change.

 

PRE-SET GROUND BALANCE

Pre-set ground balance is preset to suit a particular soil type. This limits where the detector is able to be used, but will generally work well in less mineralised sites such as parks, playgrounds and dry beach sand.

 

DISCRIMINATION

Discrimination is the ability of the detector to identify the type of metal object detected and to eliminate the unwanted items and indicate only on the desirable ones.

 

VARIABLE DISCRIMINATION

This is the most basic of discrimination types. It works like a demarcation line in the conductivity level. This level can be set by the operator and all metals with conductivity lower than where the level is set are eliminated & all metals with a higher conductivity are accepted.

 

NOTCH FILTER DISCRIMINATION

Notch filter discrimination is the ability of a metal detector to select which of the conductivity segments in the discrimination scale are active or disabled. If a segment is notched out then metals with that level of conductivity will be masked and will not produce a response.

 

SMARTFIND(TM) DISCRIMINATION

Minelab’s exclusive 2D Discrimination technology analyses a target’s ferrous (Fe) and conductive (Co) properties simultaneously. This revolutionary approach is the most accurate technology available for determining whether a target is treasure or trash.

The information can be heard as different Fe-Co audio tones, as well as being displayed numerically and graphically on a 2D scale. Individual segments or larger areas of the display can be shaded to reject unwanted targets.

 

E-TRAC SMARTFIND

The horizontal axis rates the target on its size/conductivity (CO), ranging 1–50 from left to right. The vertical axis rates the extent of the target’s ferrous characteristics (FE), ranging 1–35 from top to bottom. A FE value of 1 represents low ferrous characteristics and a value of 35 represents high ferrous characteristics. Similarly, a CO value of 1 represents low conductivity and 50 represents high conductivity.

 

EXPLORER SE PRO SMARTFIND

The vertical axis rates the target on its size/conductivity (CO), ranging 0–31 from bottom to top. The horizontal axis rates the extent of the target’s ferrous characteristics (FE), ranging 0–31 from right to left. A FE value of 0 represents low ferrous characteristics and a value of 31 represents high ferrous characteristics. Similarly, a CO value of 0 represents low conductivity and 31 represents high conductivity.

 

DISCRIMINATION SCALE

A discrimination scale segments the range of metals by their conductivity, normally from low conductivity through to high conductivity. The range and number of segments in the scale can determine the accuracy and precision of target identification. The number of segments also determines the accuracy and precision of the Notch filter discrimination.

 

TONE IDENTIFICATION

Some detectors will indicate the possible ID (identity) of a target, by changing the tone of the target signal. Generally low conductive metals will give a lower tone while highly conductive metals will give a higher pitched tone.

 

SEARCH COIL SIZE

The size of a coil can influence the detection depth and sensitivity of a detector. The larger the coil, the deeper it tends to detect, but with less sensitivity to small targets. The smaller the diameter, the more sensitive it becomes, but with reduced detection depth.

Smaller coils are lighter in weight, easier to control and may be chosen for their ability to negotiate difficult terrain or undergrowth. Smaller coils also have a target separation advantage in areas of high trash, due to their smaller detection footprint.

 

SEARCH COIL SHAPE

The most common coil shapes are round and elliptical. They are available in solid and open-web designs. Elliptical coils are more maneuverable without sacrificing ground coverage. Round coils are often more stable, higher performing, and achieve greater depth. Open-web coils are waterproof, help cut through water and assist when pinpointing because the ground is visible through the coil.

 

SEARCH COIL CONFIGURATION

The difference between configurations is the shape of the wire winding within the coil housing. The three most common types are Concentric, Double-D, and Monoloop.

 

Concentric Coil

A Concentric coil has an inner circle and an outer circle wire winding. The search pattern is cone shaped and can be useful for accurately pinpointing targets. Concentric coils require more sweep overlap for thorough ground coverage. They are also noisier in highly mineralised ground and therefore might not be the best choice for gold prospecting.

Double-D coil

A Double-D coil has two overlapping wire windings in the shape of two D’s. The benefits of a Double-D coil are stability (especially in heavily mineralised ground), good depth, sensitivity and a very thorough search pattern requiring less overlap.

When used with GPX detectors, Double-D coils (unlike Monoloop coils) are able to discriminate between ferrous and non-ferrous targets when Iron Reject is activated. They are also more stable when used on wet salt beach sand and in electrically noisy environments.

When used with X-TERRA detectors, Double-D coils perform quieter than Concentric coils in mineralised ground and are therefore well suited for gold prospecting.

Monoloop coil

Monoloop coils are a specific configuration of coil for Pulse Induction technology detectors (GPX Series). These coils have one winding of wire around the circumference of the coil, which is used to both transmit and receive. The signal pattern of the Monoloop coil is cone shaped, requiring more overlapping. In extremely heavily mineralised grounds they can be more difficult to ground balance, however they tend to achieve greater depth and are more sensitive than Double-D coils.