How deep will that metal detector go?
By Dan Breitenstein
One of the most common questions I'm asked is "How deep will that metal detector go?" Sometimes life just isn't fair because it's not only the most common question, but it's the hardest one to answer. There really is no written "set" answer that I can give without explaining what goes on down in the earth around that buried object and what happens when you stumble upon it with your detector.
I'm sure that the most basic answer I can give is that the more expensive, sophisticated models are more powerful and do go deeper. But that answer in itself is not the complete answer.
When a coin or relic is buried in the ground, the condition of the soil around it plays the most important part in whether or not you will pick it up with your metal detector. The object tends to create a halo, or electromagnetic field around it after being buried for some time that increases your detectors' ability to find it. Usually this halo will increase over time to an optimum level and then taper off somewhat.
Additional moisture in the soil increases conductivity and objects are easier to detect. That's why you'll usually find me out there after a good soaking rain, working an area that I "hunted out" when the soil was dry. This is probably the biggest shot in the arm our hobby gets from nature and we should all take advantage of it whenever possible.
The base metal itself that you're detecting is also a major factor. Iron seems to be the metal that detectors are drawn to most. Whether it's the conductivity of the base metal, or some other scientific fact, I really don't know, I'm not a rocket scientist. A good friend of mine found a toy car last year better than a foot deep, and the only metal on it was the rusted iron axels. Some folks had the audacity to doubt his claim because he wasn't using the most sophisticated, powerful model out there. But the proof is in the pudding, he found it.
Running "wide open" in the all metals mode will also give you more depth. The circuitry used to discriminate out iron and aluminum decreases your depth range somewhat. This is something that isn't really in the instruction manuals, but it's a fact. I think the manufactures know, as most of us do, that running in the discrimination mode is what most folks should do in parks and other well-groomed places. This is simply because digging everything in high traffic areas could be a major excavation and leave the land owners and park dwellers with a bad taste in their mouth for metal detecting. But turning the discrimination off does increase depth.
The size of the coil makes a difference. A larger coil diameter will usually get you more depth. Most Bounty Hunter Metal Detectors come with a standard 8" coil that provides the optimum performance for their machines for all around metal detecting. They sell an optional 10" coil that can and will add a couple of extra inches to your depth capability. Conversely, the 4" optional coil decreases your depth somewhat but affords you the opportunity to sort out multiple targets in trashy areas. All three of these coils have their place and are great options to increase the flexibility of your treasure hunting.
Outside interference can wreak havoc on your depth capability. High voltage electrical lines overhead or nearby will cause false signals and force you to turn your sensitivity down a bit and decreases your depth. Other factors of interference are obstacles like black sand, hot rocks, coal cinders, salt water, and other forces of nature are all factors in depth range simply because you have to turn your sensitivity down to deal with them.
The size of the buried object will affect the range of the detector. The larger the object, the greater depth you can detect it. I find a lot of quarters at 8"- 9" depth, but a dime at that depth is a rare treat and darn near impossible.
To answer the basic question of depth, I'm trying to impart that it's a relative thing. Yes, the more expensive models do go deeper. I use a Bounty Hunter Time Ranger and a Bounty Hunter Landstar. It amazes me how deep they will go. But, on the far other side of the spectrum The Tracker ID has proven itself to be a reliable machine that will go deeper than you would ever imagine if you know how to apply the principles of getting the most depth out of any metal detector.