How to ground balance a metal detector

How to ground balance a metal detector

Ground Balance is a variable setting in metal detector that increases detection depth in mineral ground. This earth may contain salts, such as in wet beach sand, or fine iron particles, such as red earth. These metals respond to the metal detector transmission field in a similar way to a target’s response. Due to the large mass of the earth compared to the buried target, the mineralization effect can easily hide small targets. To correct this, the Ground Balance setting removes responsive ground signals, so you clearly hear the target signals and aren’t distracted by ground noise. 

 

There are three main types of ground balancing: 

• Manual Ground Balance – Adjusts the metal detector ground balance setting manually, so that a minimum ground signal is heard. 
• Auto Ground Balance – The detector automatically selects the best ground balancing setting. This is fast, simple, and more accurate than manually set ground balancing. 
• Ground Balance Tracking The detector constantly adjusts the ground balance setting during detection. This ensures that the ground balance setting is always correct.

 

Frequency 

The frequency of the metal detector is one of the main characteristics that determine how well the targets are detected. In general, a single frequency detector transmitting at a high frequency will be more sensitive to small targets, and a single frequency detector transmitting at low frequencies will give more depth on large targets 

 

Discrimination 

Discrimination is the ability of a metal detector to identify buried targets based on conductive and/or ferrous properties. By accurately identifying a buried target, you can decide to dig it up or consider it scrap and continue searching. 

 

There are four main types of discrimination: 

• Variable discrimination – The simplest type of discrimination that uses a control knob to adjust the discrimination level. 
• Iron mask, mostly used with gold detectors to discard scrap iron. 
• Degree discrimination, allows the acceptance or rejection of certain target types. 
• Smart find – The most advanced form of discrimination. Target IDs based on ferrous and conductive properties are plotted on a two-dimensional (2D) screen. Individual parts or larger areas of the screen can be shaded to reject unwanted targets.

 

What affects the ground balance? 

If you set the ground balance incorrectly, your metal detector will incorrectly identify targets under the coil, and the target detection depth will decrease. Ground balancing is an attempt to eliminate false signals caused by soil mineralization to allow the device to more accurately detect targets. A properly adjusted ground balance metal detector greatly increases the metal detection efficiency and provides you with clearer signals and a more accurate target VDI. When tuning the machine, ideally, you should get a balance between adjusting artificially high and low. An exaggerated value of the settings parameter can lead to a situation where some of the good signals are lost and skipped with the wrong ones caused by soil mineralization. This is especially the case if the sensitivity level of the device is also set to its maximum value. In this case, the device will only bypass some targets and take them for the effects of soil mineralization. Low settings parameter values ​​have a negative effect on the metal detection process as well. In this case, the metal detector will not take into account the mineralization of the soil. The depth of detection of the device will decrease, and a lot of fake signals will appear. When balancing very high and very low device settings, you’ll get the best metal detector throughput – the maximum possible detection depth and the most accurate target signal.

How often do you need to adjust the ground balance? There is no uniform standard in this regard. You can do this from time to time, for example, once every hour. Or, for example, you can use the automatic tracking of the ground balance value. However, all automatic controls have a drawback – in this case, the detection depth decreases if compared to the manual ground balance setting (the depth in this case will not change almost). It’s up to you, though. 

 

How is the weighbridge adjusted? 

Modern metal detectors use fixed, manual and automatic ground balancing. The value of the fixed ground balance cannot be changed. It is set and adjusted within the factory environment. This type of modification is very difficult; The detection depth values ​​cannot be compared to the values ​​of metal detectors with manual or automatic ground balancing function. 

Having a stable ground balance would be a good start for the novice detector. There is no need to delve into the tuning details. You only need to turn on the device and go to the metal detector. That is why this type of ground balancing function is only encountered in entry-level metal detectors, but it has already become a thing of the past. Experienced detectors are unlikely to purchase metal detectors with a stable ground balancing value, since the device’s detection depth and sensitivity for small targets is much lower than devices with a manual or automatic ground balancing function. Ground balancing is done manually or by adjusters, when you need to hear the ground signal yourself and then set the ground balancing value. 

Another option is to let the device set the appropriate value by itself just by waving the search coil some distance above the ground. It is better to first set the ground balance value with the help of the device and then correct it and set a better value manually. This way, you will get the best and best results. 

The ground balancer will work with experienced diggers who are well aware of the behavior of a metal detector in different conditions and in different types of soil. Automatic ground balancing with traceability. In this mode, the device itself decides whether to use the ground balancing function or not, if it is necessary. Automatic ground balancing is indispensable on complex soils. 

 

How do I adjust the ground balance? 

I am trying to get the lowest value for the ground balance, but at that, the metal detector (XP Deus) should not be giving out any false signals. I use one trick that an experienced treasure hunter once taught me. 

Here are the stages:

– Find an iron-free zone. 

– Don’t dig a hole too deep (half a spade depth or more).

– I wave the search coil up the hole and listen. If the detector emits signals, I increase the value of the ground balance. 

– I keep doing this until I find the value that the metal detector in the hole does not react in any way. 

– During the metal detection process, I shift the value higher or lower, depending on the stability of the device’s performance. 

I would say that when you use this approach, you receive lower ground balance values ​​than in the case of an automatic or manual adjustment of the ground balance. At the same time, the depth of detection also increases.