Fors CoRe FAQs
1. I cannot ground balance. Why?
There may be a few reasons for this:
A) You may be ground balancing over a metal. Change your location and re-try.
B) You may be on a ground with high iron mineralization. These types of ground are beyond the device's automatic ground balancing range. Only the Conductive Ground (COG) mode will allow ground balancing on such ground. Therefore, you can select the COG mode and re-try or ground balance manually.
C) You may be on a highly mineralized ground with metal effect. In such a case, if you cannot ground balance automatically or manually including the COG mode, you need to continue searching without ground balancing. Turn off and on the device again and set the search mode to Discrimination 3 (DI3) or Discrimination 2 (DI2) (adjust sensitivity accordingly) and increase the ID Masking to a level where the noise is eliminated.
D) If the ground mineralization is too low, the automatic ground balance may not work. In this case, if the ground effect can be felt in the General Search (GEN) mode, manual ground balancing can work. If the ground effect cannot be felt, you can set it to 60.
2. What shall I do in areas with many hot rocks? We recommend you to use the DI2 or the DI3 modes and ground balance even though you can search without ground balancing. The device may emit false signals when the search coil passes over some rocks. If you get a metal signal, check the signal's continuity. If the signal is not confined to a certain spot or if the signal is only one-way when you sweep the search coil, it may be a hot rock.
3. How can I tell whether the signal is a hot rock or not?
Hot rocks are classified as negative or positive based on their ID being low or high in comparison to the ID of the soil they are in. Positive hot rocks act and sound just like metals. In the General Search mode, when you sweep the search coil over them, they tend to give a short ''zip zip'' sound. If the signal is strong enough, the device may also give an ID for these rocks but the ID will be low within the 0-10 range. In discrimination modes, positive hot rocks will give a typical metal sound again but generally users will not hear these sounds because of ID masking.
Negative hot rocks, on the other hand, tend to give a longer ''boing'' sound when the search coil is swept over them. The device will not give an ID for these rocks regardless of the signal strength or will rarely give an ID between 95-99. Negative hot rocks will not give any sound in discrimination modes (except for occasional false signals ).
4. My device is receiving a lot of noise in the General Search (GEN) mode. Why is that?
There may be a few reasons for the device to receive noise: If you have not ground balanced, the device may be receiving ground noise. In such a case, ground balance and check if the noise is still there. Another way to understand whether the device is receiving ground noise or not is to hold the device up in the air and check whether the noise is gone. If the noise is gone, it means that the noise was coming from the ground. If the noise continues, it may be due to one of the reasons listed below:
High sensitivity and threshold settings: Increasing sensitivity and threshold settings at the same time may cause the device to receive noise. First increase the sensitivity setting to the highest level where there are no popping sounds. Then increase threshold slowly to a level where you can still hear the small targets in the background sound. High threshold levels will make you miss smaller targets. Electromagnetic interference: Lower sensitivity.
Operation of another detector or a device within the same frequency range nearby: Change your location or change the frequency of the device if necessary.
5. My device is receiving a lot of noise in the DI2 mode. What is the reason?
Ground noise, hot rocks or high sensitivity setting may cause this. Discrimination 2 (DI2) mode is designed for highly mineralized ground and for areas with many hot rocks in close proximity. Ground balancing is necessary for the DI2 mode to work properly. When ground balance value is over 90, the device may receive noise from the ground or hot rocks. In the DI2 mode, a high sensitivity setting will cause the ground or environmental noise to be heard more strongly. Please keep this in mind, when adjusting sensitivity.
6. There are many other detectors in the search field. What should I do?
Operation of many detectors in close proximity to each other may cause noise. In such a case, you may have to change the frequency of the device. Normally, the frequency setting is not enabled and it is grayed out in the menu. To activate it, while holding the pinpoint button pressed, press one of the up/down/+/- switches. Then, you can select the frequency option in the menu and change it.
IMPORTANT! Frequency shifting may affect the performance of the device. Therefore, it is recommended that you do not change the frequency unless necessary and keep it at the factory default.
7. I constantly get an iron tone. What shall I do?
The search field contains a lot of iron minerals or heavy trash. You can eliminate the iron tone by setting the ID Masking value according to the target ID of the iron.
8. If I set the ID Masking to the level where iron is eliminated, do I lose depth?
You will experience depth loss in metal alloys which generate a mixed signal of non-ferrous and iron.
9. Is the target depth given by the device in the pinpoint mode accurate?
Depth reading, just like in most detectors, is provided based on the assumption that the target is a typical modern coin. The real depth will vary based on target size. The device will give a greater depth reading for smaller targets and for larger targets, the depth reading will be smaller than they really are. In fact, pinpointing is used for target location and not depth indication. Therefore, we suggest that you use the depth reading for judging the proximity of the target.
10. What are false signals and what causes them?
Sometimes the device may receive signals although there is no real target. There are a few different causes for this. Most common ones are ground mineralization or hot rocks, electromagnetic interference in the surrounding environment, operation of another detector nearby, rusty iron and corroded foil, and sensitivity and threshold set too high. False signals generally are not confined to a certain spot and they are not continuous. False signals due to high mineralization mostly result from iron oxides. On such ground, the Magnetic Mineralization reading on screen will probably be very high. Ground balancing frequently, using the Discrimination 2 (DI2) mode and lowering sensitivity will help minimize false signals.
11. Can I search without using the headphones? Why is headphone usage important?
Headphones help minimize ambient noise such as winds, waves, cars etc. Minimizing ambient noise and hearing the detector's sound only will simplify target detection and pinpointing. Headphones are essential especially in detecting smaller metals. When you clearly hear the sounds through the headphones, you can detect good targets and differentiate trash more easily which will save you digging time as well. In addition, headphone usage will prolong battery life.
12. How is the sensitivity setting adjusted?
The device comes with the ideal sensitivity setting. Sensitivity, most of the time, is adjusted unnecessarily high by users for obtaining more depth. In reality, there are many environmental factors affecting sensitivity. Factors such as high ground mineralization, radio stations and power lines in the surrounding area or other electromagnetic signals affect the level of sensitivity. The most ideal setting is where you don't get any interference and hear popping sounds.
13. What shall I pay attention to when using Ground Tracking?
For better performance, we recommend you to use Ground Tracking in the General Search mode. When the device is in GEN mode and the Ground Tracking is on, ground balancing will be updated automatically all the time. If you are looking for smaller metals, Ground Tracking is not suitable because the device will try to ground balance the signals of these small targets which may result in depth loss. In addition, if you use Ground Tracking in areas where hot rocks are intensely present, the device may not be able to eliminate these high mineralized rocks or you may miss the smaller or deeper metals. When Ground Tracking is active, the device may emit a loud audible signal if the ground conditions change (for example a hot rock) or if a target is encountered. In such a case, sweep the search coil a few times over the spot where you receive the signal. If the sound continues and the device gives an ID, there is a high chance that it is a target. If the sound gets weaker or disappears after a few sweeps, it means that that the device gave a signal for the ground change or the hot rocks. When air testing, be sure that Ground Tracking is off. Otherwise, the device will try to ground balance over the target and lose depth.
14. How can I use my device at maximum sensitivity?
This is a frequently asked and not a well-understood subject by most users. Ground and environmental conditions are the leading factors affecting sensitivity. When conditions allow, you can use your device at maximum sensitivity meaning maximum depth but please note that depth depends on a lot of factors:
Metal size (not the weight but the size of the surface seen from above by the detector), type of metal, ground conductivity and mineralization, how long the metal has been buried underground, shape and even the orientation of the metal.
*High ground mineralization affects depth considerably. Because ground minerals vary greatly, you may have to re-ground balance your detector frequently or decrease sensitivity.
*Various chemicals in the ground have corrosive effects on metals. Some metals corrode faster than others. Modern zinc coins corrode fast whereas copper and silver get affected less. Gold on the other hand barely gets affected, if at all. These chemicals eat away at the metal which cause oxidation (rusting). Rust then is absorbed into the surrounding soil. This causes the soil to become more conductive, which in turn makes the metallic object appear larger than it actually is. As a result of this, also known as the "Halo Effect", detectors detect metals at greater depths.
*The larger the metal, the easier and deeper it can be detected. For example, a bucket can be detected much easier and deeper compared to a single coin.
*The shape and orientation of metals underground are also important factors on depth. Metals act like antennas radiating part of the signal transmitted by a detector. Round objects lying flat produce the best results. Flat objects are also easy to detect. Rod-shaped items, on the other hand, are very difficult to detect..
15. How is ID Masking used?
Target ID is a 2-digit number produced by the detector and it gives you an idea about what the target may be. The number is displayed both on the LCD panel and the numeric display on the handle. ID Masking is the ability of the device to ignore (not produce a warning tone or ID) unwanted targets. As the ID Masking value increases, ground mineralization, small trash metals, pull-tabs, small nails, folio, gold rings and some coins will be ignored in order by the detector. Therefore, it is important to check the IDs of certain targets before using the device. Please keep in mind that with a high ID Masking value, many non-ferrous metals will be rejected. When you set the ID Masking to 35, the device will reject ground minerals, iron and trash metals and will detect alloy metals, non-ferrous and gold targets.
You can easily use your device on wet beach sand by using the Conductive Ground (COG) mode and automatically ground balancing. This is the special mode of FORS CoRe designed for conductive ground (wet beach sand, alkali sand etc.). What is special about this mode is that it will not react to iron or similar targets within the same range and that the device will ground balance easily on all types of ground. Another way is to use the DI2 or DI3 mode, ground balance manually and to increase the ID Masking value until the iron tone is eliminated.
17. Can I search on dry beach sand with my device?
All the modes can be used when searching on dry beach sand.
18. Can I submerge the device in water?
FORS CoRe search coils are all waterproof so you can submerge the coils and the shaft up to the handle in water but you should not get the system box or the handle wet.
19. What should I pay attention to when searching on the beach?
You can get metal signals when you sweep the search coil over the holes you dig on wet beach sand, this is normal. Don't forget the check the sand you dig out for targets. The search coil may give false signals when going into and coming out of the water so please try to keep the coil either in or out of the water.
The salt and mineral levels especially in wet beach sand may change as you change your spot so ground balancing frequently during prolonged searches may increase the device performance.