Metal Detector Discrimination Chart
by Daniel Bernzweig
Metal detectors with discrimination capabilities can filter out certain types of metals, making it easier for users to find the objects they're looking for while metal detecting. The most common type of discrimination is based on conductivity, which means that the detector can tell the difference between metals based on how well they conduct electricity.
Understanding the discrimination settings on your model and how they work is key to becoming a successful metal detectorist. This article will explore how discrimination works, how to set discrimination on your metal detector, and how you can use each setting to your advantage.
What Does Metal Detector Discrimination Mean?
Whether you are metal detecting as a hobby, gold prospecting, or treasure hunting, knowing how to set the discrimination on your metal detector can help you find what you're looking for more quickly and efficiently. All targets have a unique level of conductivity. A metal object like coins, jewelry, precious metals, and relics conduct electricity differently than other objects like:
- An iron nail
- Foil wrappers
- Bottle caps
Metal detector discrimination or DISC refers to the act of removing or notching out (notch discrimination) particular types of targets on a metal detector to only display a visual or audible indication when a specified target is discovered.
The easiest way to understand how discrimination works is by thinking about a spectrum of conductivity, with nails and foil at one extreme and gold nuggets at the other. Sensitivity is set to the point where all targets will give a response, but discrimination allows you to ignore certain types of objects by notching them out.
Some detectors even have auto-discrimination features that do the work for you. When set to auto-discriminate, the machine will emit a target signal when it detects a target that falls within the range of conductivity levels that you've specified. This is sometimes called pre-set discrimination patterns.
How Metal Detector Discrimination Works
The search coil of a metal detector consists of two electromagnetic search coils, the transmit coil and receive coil, which produce the field and receives the resulting signal. Coils come in many forms, most commonly double d coils, concentric, or butterfly coils.
The conductivity of a metal target will cause a change in the magnetic field, which is detected by the receive coil and processed by the electronic circuitry to produce an audio or visual signal indicating the presence of a target like treasure or hot rocks (gold, silver, copper, etc.).
Most very-low-frequency (VLF) multi-frequency or single-frequency detectors will come equipped with a DISC feature. By setting the discrimination properly, you can filter out junk and still locate good targets with ease. A pulse induction or pi metal detector does not discriminate as well as a very low very frequency circuit. It operates by sending out short bursts of energy that penetrate the ground to a detection depth of several feet, making it ideal for gold prospecting.
However, PI detectors are excellent for detecting smaller objects like a gold nugget or coin, so if you're interested in finding a mix of targets, you'll want a metal detector with discrimination capabilities.
Metal Detector Discrimination Chart
Above is a chart showing the discrimination conductivity range of common targets found with a metal detector. Using the metal detector discrimination properties shown in this chart, you can easily understand the targets you have located.
Most metal detectors have a coin mode, once activated, the unit will only make your detector sound off for most coin-shaped objects and eliminate iron targets such as nails. Doing this saves time from digging up nonvaluable items like rusty nails and the like. You'll know you've found a coin-shaped item when you hear a higher-pitched noise from the device.
Metal detectors have various discrimination modes, such as relics, jewelry, and custom. There's also an all-metal setting that distinguishes nothing among the metals. The detector will find everything it comes into contact with in this mode. Some of the best metal detector models for discrimination capabilities include:
Popular Models with Discrimination Capabilities
Bounty Hunter Platinum Pro
With the Bounty Platinum Pro, you can choose an all metal mode, full notch discriminate, or audio tone discriminate. Most trash items will be instantly rejected when using the Full Discriminator. Increase the discrimination control to increase the range of discrimination.
Garrett Ace 400
From Garrett Metal Detectors, the Garrett Ace 400 features a very nicely laid out color discrimination legend right on the display. You can easily recognize targets based on the easily visible target id range. For example, iron, silver, gold, and aluminum are clearly indicated in the legend.
Garrett AT Max
The Garrett AT Max is a top performing all terrain metal detector with full discrimination capabilities. An expanded iron range is a favorite of relic and water hunters alike. If you are new to detecting or an experienced detectorist, this is one of the easiest models to learn.
Garrett GTI 2500
LCD gives you multiple options, including a target ID legend, coin depth indicator, zero DISC mode, jewelry mode, and custom and notch discrimination. The Garrett GTI has a sensitivity/depth adjustment and a preset or manual ground balance capability. This model also features treasure vision which helps you identify the target size. This is helpful if you are metal detecting for multiple targets with similar conductivity but different sizes. You can easily determine if a target is worth digging for based on this additional dimension of information.
XP DEUS II
The DEUS II model has a crystal clear backlit target ID display. This model also has a wide Iron range, which allows you to tune out problematic iron trash and tailor your discrimination even more, to avoid false signals while metal detecting. Ultra-stable operation in any ground mineralization conditions helps you to find more and penetrate deeper into the ground.
Many experienced users also like that the unit includes preset Coin, Relic, Gold Nugget Prospecting, and Jewelry modes making treasure hunting a breeze. The more you use your machine, the better you'll understand what each type of target sounds like and the amplitude of the signal on the screen. This detector is considered to have the fastest response speed and clearest separation of targets. Use on land and underwater to a depth of sixty feet.
Nokta Makro Simplex
Nokta Makro’s Simplex is a great choice for those new to the hobby metal detection world. It has a user-friendly interface with easy-to-understand menus. The Simplex features notch discrimination, which allows you to select or deselect certain targets while metal detecting.
The threshold setting for each sensitivity level is optimized in the All Metal mode to provide the best performance on various terrains.
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