Metal detectors for dedicated treasure hunters
Find the perfect tool for your searches
Metal detectors
Enjoy exploring with metal detectors
What is a metal detector?
- People screening - We’re all familiar with the security checks at airports – no one is allowed to board a plane without first being screened by a metal detector.
- Testing of food, medicines, etc. - Even the best machine will exhibit signs of wear over time. Metal detectors are important tools in ensuring that metal chips do not find their way into products during manufacturing.
- Archaeology - During excavations, metal detectors can help with the exploration and recording of archaeological sites.
- Trade - You can never quite tell where pipes and wires are located in the walls of your home. Metal detectors can be used to help locate them and to prevent unwanted damage.
- Explosive ordnance disposal - Metal detectors can help to locate and professionally remove land mines, unexploded bombs, ammunition, etc.
Structure and function types of the metal detector
- Pulse measurement - With this method, pulses of a magnetic field are emitted at specific time intervals. If metallic objects are located in the vicinity, eddy currents are generated within them. Once it has emitted the magnetic pulse, the metal detector switches to receive mode. The eddy currents then cause a change in the signal that can be directly measured as a voltage. In order to determine the size of the object and the metal type of the object, the time progression as well as the duration of the eddy current responses to pulse sequences and pulses of different lengths are evaluated.
- Alternating current excitation - This method uses an uninterrupted alternating current in the coil. Here, two different methods are distinguished:
- a. The first is the attenuation analysis, where a low-frequency signal of approx. 10 kHz is emitted. The received signals are constantly analysed to determine their amplitude and phase position. Changes to these two values when compared to the transmitted signal offer an indication of the material and size of the metallic object.
- b. The second is the BFO technique, where two oscillators constantly emit electrical signals at two different frequencies. The superimposition of the two frequencies creates an acoustic signal that changes in pitch as soon as a metallic object is located nearby.
Analogue or digital – which metal detector is the right one to use?
Digital | Analogue |
More accurate measurements | Information about metal type only possible via acoustic signal |
Variety of setting options for differentiating between diffrent materials | Number of setting options limited |
More weight due to more complex measurement technology | More lightweight design |
Higher power consumption | More energy efficient |
More complex in operation | Easier to operate |
Finding the right metal detector – tips for searching
- Weight - One aspect that must not be underestimated when choosing a suitable metal detector is its weight. After all, once the passion is there, you’ll no doubt want to spend as much time as possible enjoying your new hobby. Every gramme of weight saved will relieve the arm that holds the metal detector.
- Ease of use - As with any new hobby, you’ll want to score interesting results as quickly as you possibly can. So a metal detector that’s easy to operate is a must. Analogue metal detectors, or digital metal detectors with a higher degree of automation, can bring plenty of enjoyment.
- Search depth (also depth performance, search performance or locating depth) - Many interesting objects have been lying in the ground for a long time and are accordingly not directly below the surface. The maximum search depth of a metal detector indicates how deep the metallic objects may lie in the ground so that the metal detector can still locate them. At this point, 25 cm for coin-sized objects and 80 cm for larger objects are considered average values. Practical: Some metal detectors can also indicate how deep the located item actually lies in the ground.
- Adjustable sensitivity - It’s useful to be able to adjust the sensitivity of your metal detector, particularly in difficult soil conditions, such as heavily mineralised soils. That way, you can prevent faulty signals.
- Pinpoint mode - Some metal detectors offer a pinpoint function, so that you can easily identify the precise location of an object. After all, if a metallic object has been in the ground for a long time, it will start to look like the ground around it, and actually locating it can be challenging.
- Wearing comfort - Moving a metal detector back and forth over the ground over a long period of time can become exhausting, and it’s important to consider comfort when deciding what to buy. Some metal detectors have padded handles, for example, and ergonomically shaped shafts that can be adjusted to your body size.
- Headphone jack - If your hunt is in an area with a high level of background noise, it can be worth using headphones. That way, it will be easier to identify changes in the acoustic signals, plus, it’s more considerate to the people around you.
- Search coil size - The size of the magnetic field also depends on the size of the search coil. A metal detector with a larger coil diameter will allow you to search a much wider area.
- Discrimination - This function can be used to filter waste and other unwanted objects out of your search. The discrimination function allows you to choose which metals to ignore.
- Waterproof coil - Anyone considering searching near water should consider opting for a metal detector that can tolerate moisture.
The law – what are you actually allowed to do with a metal detector?
- Marked and unmarked archaeological monuments
- Nature reserves
- Cemeteries and graves (also former burial grounds and mounds)
- Forests and unmanaged meadows
- Historical sites (battlefields, camps)