This seems easy. You increase the metal detector’s sensitivity and scan deeper. It’s true; you can do this, but be ready to dig a lot more trash than treasure. By just increasing sensitivity, even the smallest of broken nails will sound like you hit a jackpot.
So, how to detect deep targets using a metal detector? If you want to be an expert in this, then this guide is for you. We have developed very comprehensive content on detecting deep targets using a deep seeking metal detector.
1.0 Understand the Deep Metal Detecting Project
Your deep metal detecting project is not just about making some adjustments and doing some settings on your deep seeking metal detector. It needs a lot more work for you to have an understanding of what you want to detect.
1.1 Understanding the Treasure
The first thing you need to understand is not the equipment; it’s the knowledge of the treasure you want to detect. It is important for you to know what type of treasure you will be detecting. You need to know the average size, shape, and materials.
This will be the hardest and the most time-consuming step. You might need to talk to local people and look for the information that has been passed from generation to generation.
Gain as much knowledge as possible about how people live there, what valuables they possess, what was the common metal of use, and most importantly, what things they considered valuable and how they protected them.
1.2 Estimate the Average Depth You Need to Scan
After gaining all the history of the area, it is important to put some time into estimating how deep you need to scan. This is very important as you can miss a highly valuable target that is buried an inch deeper than what you were scanning.
You can estimate this from history and how old the treasure you want to dig is. The older the history of the item, the deeper it might be inside the earth’s crust. You have a good estimation of what depth to target during your deep detecting project.
1.3 Understand the Site
It’s important for you to understand the metal detecting site, soil composition, the local weather, and the type of terrain you will be scanning. Different types of soil composition respond differently.
Moist or soft soil makes it easy for the electromagnetic waves to pass through, thus increasing detector sensitivity, which can potentially increase detection depth. Highly mineralized soil or salty water in the soil can reduce detector penetration power and make it difficult for the scan without doing ground balancing.
The above information about the treasure, its depth, and the soil condition will help you select the best deep seeking metal detector.
2.0 How to Detect Deep Using a deep seeking Metal Detector
A deep seeking metal detector is the term given to a metal detector that has the ability to scan deep down into the earth’s crust. There is no minimum or maximum limit that can filter a normal detector from a deep seeking metal detector. These detectors are usually pro-level metal detectors and are used to scan depths from 3 feet to a few meters.
2.1 Select the Best Deep Detecting Technology
Impulse Induction (IP) Metal Detection and Very Low-Frequency (VLF) Metal Detection are the two main technologies behind deep metal detection.
Impulse Induction deep seeking Metal Detectors
In impulse induction, short but rapid electricity pulses are sent to the detector’s coil. This develops a magnetic field around the coil. This magnetic field can travel deep and magnetize any metallic object, irrespective of its size, shape, and material.
One big advantage of IP detectors is that they can be used in various soil compositions and conditions like magnetite and magnetic hot rocks, saltwater beaches, saltwater oceans, dry sand, and wet black sand.
As IP technology detects objects by receiving their dying electromagnetism, it is not affected by the depth, mineralization, or conductivity challenges of soil. If your treasure depth is more than a meter, then the IP technology-based Detech SSP 5100 deep seeking metal detector system is highly recommended.
Very Low-Frequency deep seeking Metal Detectors
VLF metal detectors are just like a professional metal detector that can scan a few inches into the earth with one big difference: they operate on a very low frequency. This low frequency helps them scan deep into the earth and detect specific metallic objects that have high conductivity, like gold, silver, and copper.
2.2 Select Proper Coil Size
Search coil size is an important factor and, for most people, the only factor when they buy a deep seeking metal detector. With that, most people use one single rule too: the bigger, the deeper. Coil size is important, and big-size coils do go deeper, but this selection is highly influenced by the research you have done about the treasure and its depth.
If you are scanning for standard-size coins, then a 12-inch coil will work better and deeper than a 4-inch coil. If you go even bigger, like an 18-inch or 24-inch coil, their performance in detecting the same coins will not be as good, and detection will not be as deep as it was with a 12-inch coil. This is because smaller coils are better at concentrating magnetic energy on smaller areas, thus detecting smaller coins efficiently.
If you want to scan big and deep targets only, small coils will not do the work. If you want to scan up to 2 to 3 meters, then you need a coil of about 1.5 by 1.5 meters to 2 by 2 meters. There are systems that offer metal detectors with search coils in meters, like the Detech SSP 5100 deep seeking metal detector system.
Their biggest search coil is 2 by 2 meters, and the smallest is 18 inches in diameter. With their biggest coil, they can scan up to 8 meters into the earth’s crust but only detect treasure that is at least a few inches in dimension.
So, select the search coil size based on the initial research about the treasure’s size, shape, and depth. You can go big for deeper and bigger targets, medium for smaller and deeper targets, and smaller for shallow targets.
3.0 Understand deep seeking Metal Detector Settings
This is purely based on the initial research you have made about the treasure, its depth, and soil conditions. There are several deep seeking metal detector settings to play with here. The first of those is the sensitivity of the detector.
3.1 Sensitivity vs Depth in Deep Scanning
The higher you put the sensitivity of the metal detector, the deeper the scan. So, adjust the detector sensitivity depending on the initial research and testing of a small patch of the site. It is recommended to increase it from 40 above in intervals and see what is best for you.
3.2 Discrimination Setting for High-Conductive Targets
If you increase the discrimination setting to above 65 to 70 and combine it with higher sensitivity, you will only hear when metal detectors hit deep high-conductive materials like gold, silver, or copper. Like sensitivity, you can test different discrimination settings and see what set is best for you.
3.3 Audio Response and VDI Number for Deep Targets
This is a tricky step. Audio response is how loud you hear the beep of your metal detector based on the depth of the treasure. If you maximize your audio response, you will hear a very loud/sharp sound from the target that is on the surface and a very soft sound from the target that is deep inside the earth’s crust.
This high sensitivity, high discrimination setting, and soft sound, together with a selected range of VDI numbers, can help you scan deep into the earth’s crust and leave any trash present on top of the earth’s crust. If you go for the Detech SSP 5100 deep seeking metal detector system, their system offers visuals of what is buried deep inside the crust.
4.0 Some General Tips for Better Deep Target Detection
- Walk in a straight line in a slow and steady manner, and always sweep slowly and in a fixed pattern.
- With a fixed sweeping pattern, try to produce overlapping while you sweep. Try to have at least a 50% overlapping ratio.
- Listen for faint sounds. A faint sound can indicate that a target is small or deep.
- Be prepared to investigate suspicious targets. Be ready to investigate targets that seem suspicious.
- If one of your metal detecting strategies produces any result in any given site, try to scan the site again with another strategy or a different deep seeking metal detector setting. You might find what you previously missed.
5.0 Conclusion
The question of how to detect deep targets using a metal detector is tricky. It depends a lot on the treasure’s size, material, depth, and soil composition. Depending on the technology and coil size of the deep seeking metal detector, you can scan up to 8 meters into the earth’s crust. Try to have the best combination of settings based on your initial research and the results of test runs on-site.
