How Deep do Metal Detectors go? (2022 Guide)
When it comes to metal detecting, then the kind of device you have will determine the depth at which you find metals and the kind of metals you find. If you are like most people, you probably think that once you purchase a metal detector, your pursuit of metal detecting is over.
There certain factors that influence what you find. If you are prospecting along the seashore, then expect many false signals due to the highly mineralized soils. While the chances of finding something valuable that has been washed ashore is high, there is also a high chance of digging for old nails.
If you want to know the depth of metal detectors, read on.
Type of soil
The grounds you are prospecting will determine how deep a metal detector can go. If you are looking for items like coins or jewelry, then a depth of just 6 to 10 inches is fine. However, gold is heavier and is often buried deeper in the ground. Larger objects can be found deeper at over 16 inches below the ground. This requires more powerful detectors.
When searching through various soils, you may want to keep in mind that the larger the object, the easier it is to detect it. Also, the soil composition will affect the signal strength. If you are in highly mineralized soils, then it would be better to have a device with discrimination features. Check whether there other metallic objects that can affect the signal strength. Note that brass, copper, and silver has higher conductivity than metal like steel. This means a steel object may be harder to detect in deeper depths.
The soil mineralization, when used in reference to metal detecting, is how concentrated the soil is with metallic compounds. This means your device will constantly be picking false signals in such kind of soils. The situation is worsened if you are in an area with a lot of iron. This will affect your machine operating depth and detecting range. To sort out the mineralization of soils, devices will come with discrimination features like manual or automatic ground balance settings.
The ground you are in will also affect your detecting abilities. Wet grounds are preferred to dry ones. What many people do not know is that wet grounds increase the sensitivity of your device. This makes it easier to detect targets. When it is moist, it is also easy to dig in for targets. If you are going to be hunting on wet grounds, it is prudent you go with a metal detector that is waterproof. If it is in shallow waters, identify one that has a submersible coil. Most of the devices do not have waterproof control boxes, so you have to be extra careful; it does not get splashed with water.
At the end of the day, it simply boils down to coil size. The quality and size of the coil will determine how deep it goes. The rule is the larger the coil, the deeper it can detect, but this reduces its sensitivity to small items. When you go with a smaller coil, then you are going to enjoy higher sensitivity but at the expense of depth. The coils are also lightweight making them ideal for beginners and kids new to the hobby. Expensive metal detectors will come with double coils that vary with diameter. This allows you to dig and varying depths.
Not all metal detectors operate on the same frequency. Those that are designed for gold prospecting operate at higher frequencies than the rest. If you want to detect high conductivity objects like silver, then go with one with a low frequency. However, this will not be good for detecting small objects. Higher frequency metal detectors have a short wavelength hence not suitable for deeper depths. To mitigate all these challenges with metal detector frequencies, you have those that come with multiple frequencies. The range and type of metals identified with such kind of devices is expansive.
You should note that a pulse induction detector will detect items at deeper depths than the VLF frequency detector. But, on the downside is there are more expensive. Most of the pulse induction detectors are expert level and used for gold prospecting. They are also more complex to operate than the VLF detectors. Some detectors will come with some innovative technologies that boost your prospecting success. These also come with intuitive LCD screens that even have GPS mapping.
Other important considerations
Your odds of finding something valuable in a lost, forgotten town are higher with the right equipment. The misconception people have is that such items are buried deep in the ground. But, it is the reverse. Relics and old coins are often found on the surface level. You will find them within digging 3 to 20 cm. These items have been buried in the ground by rainfall. You will need a scoop to dig through the top dirt. The digger you dig – above 30cm- the less unlikely you will find long lost relics.
When you are going for metal hunting on the beach, note that the salty waters are highly mineralized. This means your detectors is going to be receiving constant false signals. But, the beach offers good grounds for prospecting for jewelry and gold nuggets that have been washed ashore from the deep sea. The ideal detector is one that has a waterproof and submersible coil. Such coils can operate to a depth of up to 200 feet.
Here is an estimate for most metal hunts:
- Old coins – 10 to 15 cm
- Small and large jewelry – 7 to 30 cm
- Cannon shell – 60 to 90 cm
- Bicycle license disc – 20 to 40 cm
- Coffee can size – 30 to 60 cm
You will also need to consider you budget before you can start metal prospecting. If all you want to find are some hidden old coins or jewelry, then it would not make sense to purchase the high-end metal detectors. This are more expert level and will need the skill to operate. On the other side, do not buy a toy as a metal detector. Some of the things sold at most departmental stores are actually toys that do very little to improve your odds in finding something valuable.
Before you can continue metal detecting in certain locations, ensure you have the license to do so. Metal detecting in national parks and private property is highly prohibited. However, it is okay to do prospecting along your riverbed. Check with the local authorities on what is permitted. If you are going to be doing metal detecting in a public place, ensure it is low traffic, and you cover the ground after searching. Most of the metals are often concentrated in regions. What this means is that if you find something valuable in one region, you should go on digging as you may uncover something else.
To properly understand the depth of metals in certain areas, you will need to do adequate research. This means heading to the library and digging in the best places for metal hunts. You can talk to your local geology department.
Metal hunting is a hobby that can be carried out by both the young and the old. It offers an opportunity to learn and uncover some valuable treasures. However, you need to identify the depth of the item you are searching for. This means finding a device with the right frequency and coil diameter. The rule is the larger the coil, the deeper it goes but at the expense of sensitivity.