What do metal detectors detect? This question has been consistently asked by curious individuals over the years. In fact, even the most seasoned metal detector users still pose this question online. Like the name suggests, metal detectors are designed to detect metals of all shapes, sizes and grades. However, there are certain metals that these popular units can and cannot detect. According to industry experts and unit sellers, here are the guidelines to consider when purchasing metal detectors for work or play.
Metal Detector Systems
Metal detectors are built to detect most types of metal. This includes ferrous (magnetic), non-ferrous (non-magnetic) and stainless steel. These units also detect the following metals:
Most metal detectors are considered general-use units. This means they are used to comb beaches for buried metal objects; coins, jewelry, and metal scraps. However, there are non-portable and stationary metal detectors as well. These are basically used by companies –across several industries — to distinguish between different metal alloys and grades. With this in mind, let us take a look at the different metal types and which ones are easy to detect — and not.
Ferrous metals are attracted to magnets — namely iron and steel. These metals are considered the most easy to detect –but are the most common contaminants in industrial environments. These easily detectable metals also tend to rust when exposed to air and water for prolonged periods. Examples of ferrous metals include:
• Pins and staples
• Screws and nails
• Washers and welding slags
• Rusted items; cans and tins
• Scrap metal pieces
• Steel parts
Non-ferrous metals are considered non-magnetic metals. This includes copper and aluminum, along with brass, lead and more. Manganese is also known as a non-ferrous metal and very hard for metal detectors to detect. Non-ferrous metals may be detected depending on whether they are mixed grade metals or not.
Stainless steel is definitely the hardest metal to detect for metal detectors. This is due to their poor, electrical conductive qualities. Stainless steel also has low magnetic permeability — and therefore — very hard for general-purposed detectors to pick up via signals.
What Metals Cannot Be Detected By A Metal Detector?
Metal detectors can pretty much detect all types of metals. Some are harder to detect than others.
Different Types of Metal Detectors
What metals can a metal detector find? Now that we know the answer to that question, let us explore some of the features of metal detectors. Most units, of course, are electronic devices fitted with large coils of wire. Many units also include transmit coils, along with second coils of wire for precise and accurate detection. The receive coil indicates if buried metals are present via speakers. With this in mind, users are then able to pinpoint the exact locations of these buried objects –usually in public parks, beaches, or open space areas with plenty of trees and vegetation.
Some of the most basic types of metal detectors are used in industrial and security industries. However, most units are utilized for gold prospecting, along with underwater and salt beach areas. Some are used for cache hunting, as well as deep-searching projects and excavations. There are literally thousands of metal detectors available on the market today. In fact, you have probably seen an info-mercial or two showcasing the many benefits of using metal detectors to find hidden gold –or as a fun and enjoyable hobby for friends and loved ones.
As we pointed out earlier, metal detectors can detect a range of metal alloys and items. However, there is a way to distinguish between certain metals as well. These features are included in most detectors and are called “discriminators”. The latter can be set to send out signals pertaining to a specific metal or alloy. For example: you can program your detector to find nickel coins only if desired. Similarly, you can set the unit to detect gold, bronze, copper wiring, and other metals as well. This makes this activity quite fun — since there is something so challenging about finding lost treasure or hidden items worth a pretty penny.
Understanding Metal Detector Signals
When it comes to metal detectors, some are equipped with high-frequency properties. However, most are built with low-frequency features that can still pick up strong signals. These are usually signals from ferro-magnetic substances such as iron-bearing minerals or grains in sand and soil. Metal detectors are designed to receive signals from these particles, which tend to be thousands of times stronger than signals from small metal objects. Metal detectors, however, are created as “ground-balanced” units, which mean their detectors are not far off from the ground level. This is why they still pick up signals related to coins and jewelry. It is also important to note that high-frequency detectors are unable to detect and target natural gold.
Non-general Purpose Detectors
As mentioned earlier, there are non-portable metal detectors on the market as well. While these units are bulkier and larger in size, they are surely not mobile and lightweight. Still, they can be moved from area of your business to another with the right pulley or vehicle. Many of these metal detectors are used as industrial applications in the military, as well as aviation. In fact, you often see metal detectors at airports — and sadly — at several schools across the nation and world. Metal detectors are even used in food processing plants, as well as construction and garment industries.
The Metal Detector Craze
While metal detectors are certainly not new, they continue to soar in global popularity. In fact, the newest units reflect advancements in both detection and signal technologies. Most metal detector companies have also revamped their units to detect — reflect — and display hidden metal objects across the board. Some units even allow users to transmit captured images to their e-mail and/or social media accounts.
The ultimate goal of any metal detector user is to find buried or hidden metal objects. Whether this is uses for gold prospecting, financial gain or simply enrichment via fun and energetic hobbies tends to vary a great deal. Still, if you want to purchase a metal detector for your fun or industrial applications, you will find a wide array of units and accessories online.