What is ground balance function for, and how does it influence the metal detecting process?

When I took up metal detecting, I didn’t understand much, especially when I heard such words as discrimination, ground balance, mineralization, etc. I didn’t adjust the ground balance. I just turned the metal detector in and hurried to start treasure hunting.

Moreover, even sometime later, I was still using automatic manufacturer’s settings, and these were quite enough for me. Only when I became a more experienced digger, I started to see how important is proper setting and adjusting of the ground balance. This is the experience I’d like to share with you here.

Soil mineralization and its influence on a metal detector

Many beginner treasure hunters are interested in why the air test results of a metal detector differ from the ones obtained on the ground? The thing is that the ground itself acts as a noise for a metal detector, especially if there are a lot of minerals in it.

Soil mineralization means that there are some electrically-conductive admixtures in it, such as iron oxides or magnetic impurities that can hide non-ferrous targets from you. At that, the soil mineralization level can be different; it can change even within one field.

Alkali and solonetzic soils have a high level of mineralization. The soil has a lighter tint, and there is some small vegetation there, or it is completely absent. Also, seawater has a high mineralization level, so going beach hunting with a metal detector without a ground balance function is complete torture.

Mineral inclusions make your metal detector produce false signals, which interferes with the metal detecting process a lot. You just won’t hear signals from small and deep targets.

To neutralize these false signals, a ground balance function is used. Therefore, when you go metal detecting, setting the ground balance is a must.

What does ground balance influence?

If you set ground balance incorrectly, your metal detector will define targets under the coil incorrectly, and target detection depth will decrease. The process of setting the ground balance is an attempt to remove false signals caused by soil mineralization to let the device detect targets more precisely.

A metal detector with a properly adjusted ground balance function significantly increases the metal detecting efficiency as well as provides you with clearer signals and a more precise VDI number of the target.

When adjusting the device, ideally, you should get the balance between the artificially high and low adjustment.

An overestimated value of the settings parameter can lead to the situation when some good signals will be lost and skipped together with false signals caused by soil mineralization.

This is especially the case if the device sensitivity level is also set to its maximum value. In this situation, the device will just skip some targets taking them for the soil mineralization effects.

Low settings parameter values have a negative impact on the metal detecting process as well. In this case, a metal detector won’t consider soil mineralization. The device detection depth will decrease, and lots of phantom signals will appear.

When getting the balance between too high and too low device settings adjustment, you’ll obtain the best productivity of your metal detector – maximal possible detection depth and the most precise target signal.

  • Do you want to get several additional centimeters/inches to the device detection depth?
  • Do you want to hear a coin next to a large corroded nail?
  • Do you want to hear signals from all targets underground?
  • Do you want to get more target signals?
  • Do you want to receive deeper signals?

Set the ground balance – this is the answer.

How often do you need to adjust ground balance?

There is no unified standard in this respect. You can do it from time to time, for example, once in an hour. Or, for instance, you can use automatic tracking of ground balance value.

However, all automatic controls have a drawback – in this case, the detection depth decreases if compared with a manual ground balance setting (the depth will be almost unchanged in this case). It is for you to decide, though.

How to adjust the ground balance?

Modern metal detectors use fixed, manual, and automatic ground balance.

The fixed ground balance value can’t be changed. It is adjusted and set within the factory environment. This kind of adjustment is quite rough; detection depth values can’t be compared with those of metal detectors with manual or automatic ground balance function.

The presence of a fixed ground balance will be a good start for a beginner detectorist. There is no need to dig deep into adjustment details. You just turn on the device and go metal detecting. That is why this type of ground balance function is encountered only in entry-level metal detectors, but it already becomes a thing of the past.

Experienced detectorists are not likely to buy metal detectors with fixed ground balance value, since the device detection depth and sensitivity to small targets are significantly lower, than that of the devices with manual or automatic ground balance function.

Manual ground balancing is performed manually or by the adjustment tools, when you need to hear the ground signal yourself and then set the ground balance value. Another option is to let the device set the proper value itself just by waving the search coil at some distance above the ground.

It’s better first to set the ground balance value with the help of the device and then to correct it and set a better value manually. This way, you’ll get the best and the most optimal result.

The ground balance will work for experienced diggers who are well aware of the metal detector behavior in different conditions and on various soils.

Automatic ground balance with a possibility to track it. In this mode, the device itself decides if to use the ground balance function or not, if there is such a necessity. Automatic ground balance is irreplaceable on complex soils.

How do I set the ground balance?

I try to get the lowest ground balance value, but at that, my metal detector (XP Deus) shouldn’t produce any false signals. I use one trick, which an experienced treasure hunter taught me once.

Here are the stages:

  1. I find an iron-free area.
  2. Dig not very deep pit (half spade’s depth or more).
  3. Выставляю БГ на минимальные значения.
  4. I wave the search coil above the pit and listen. If the detector produces signals, I increase the ground balance value.
  5. I continue doing so till I find the value at which the metal detector doesn’t react on the pit in any way.
  6. During the metal detecting process, I shift the value higher or lower, depending on the device’s performance stability.

I’d say that when using this approach, you receive lower ground balance values than in the case of automatic or manual ground balance adjustment. At the same time, the detection depth increases as well. You are welcome to try the approach mentioned above. Maybe it will work for you.

About Peter Harrington

Peter Harrington is actually the founder of UnderCoil. He is keen on relic hunting, antiquities collecting and a big fan of aquarium husbandry.

His favorite season is early spring. Peter likes studying new models of metal detectors and creating new site content. However, he’s not into social networking stuff.