Metal detector "Terra-N": description, characteristics, instructions and references

The manufacturer positions the metal detector "Terra-N" as a device with an optimal ratio of price and quality, intended for novice treasure hunters. Low weight, affordable price, ease of adjustment and high sensitivity made the device really popular.

About the device

The metal detector "Terra-N" serves to search for metal objects in soils that do not conduct electric current. The device uses digital signal processing from the sensor, which provides stability and high sensitivity. Data is analyzed using a high-frequency microcontroller, which allows you to quickly process the signal and display information on the panel in real time. Thanks to the use of a waterproof housing, the device can be operated under difficult conditions, without doubting its reliability.

The device has an unlimited resource, since its design does not contain parts with limited operating time. The main advantage of the device is simplicity in use and increased depth of detection. For example, a metal coin "Terra-N" is found at a depth of up to 25 cm, and a car - up to 2 m. The adaptive function for soil characteristics is available, which reduces the number of false positives by an order of magnitude. Characteristics of the metal detector "Terra-N" allow using it at a temperature from -25 to +80 degrees.

Operation with the device

1. Sensitivity adjustment. By changing this parameter, you can adjust the depth of the search. When working with metal-containing ground, giving background noise, it is recommended to reduce the sensitivity until the noise disappears. When searching in an unfamiliar area, the sensitivity should be set to the minimum level, and then, in the absence of interference, gradually increase.

2. Select the trigger threshold. The metal detector shows the size of the object, provided that the signal level exceeds the set threshold. The threshold should be set based on the search target. The first level is chosen to search for small items: coins, chains, relics and other items that require high sensitivity. The second level is used for medium objects: pipelines, hiding places, and also in the presence of a small number of metal occurrences in the soil. The third level is needed to find scrap metal, as well as to eliminate interference from medium sized items.

Selecting the search mode

1. Dynamic search mode. In this mode, the metal detector will only output a signal when the sensor is moved above the search object. If there is no movement, the instrument will show a zero signal. This mode is for quick searching. It uses a two-tone sound signal: a high tone sounds when non-ferrous metals are detected, a low tone - if a black metal is found.

2. Static search mode. In this mode, the device will emit a signal throughout the entire time the object is under the sensor. The volume of the sound will increase as you approach the object, and when you move away, it will decrease. This mode is used to accurately determine the size of the object and its location. When finding the object, the device sounds its characteristics with a 30-tone sound scale: black metal corresponds to a low tone, color - high. The signal level is directly proportional to the size of the object.

Battery charge

If the battery voltage drops below 7.5V, the battery needs to be replaced. With a low charge, work with the device is possible, but its sensitivity will be significantly lower.

Search Technique

The device is recommended to be held in the hand so that the user is most comfortable. The sensor coil should be moved with arcuate movements, following the stroke, moving halfway forward. This technique is called scanning. The coil must be kept at a constant height for a stable detection depth. When searching fast, you should select dynamic mode. The coil is allowed to be carried on grass or ground, this does not affect the quality. Scanning should be carried out at a speed of up to 1 m / s. When a metal object is detected, the device beeps and the indicator displays the size of the object.

Locating

If there is a need to accurately determine the position of the object, it is recommended to use the static search function. In this case, the coil of the device is moved by the technique of the cross. The sensor is moved first left-to-right, and then back and forth, trying to find the point where the signal deviates most. By the same principle, you should search for the subject in dynamic search mode. The instrument will sound if the object is located exactly under the sensor. The search process is simplified with a small scanning speed.

The device circuit

The electrical board of the device has the form shown in the figures below.

As you can see, the scheme of the metal detector "Terra-N" except for small elements contains only a processor and a field-effect transistor. According to experienced electronic amateur fans, this is catastrophically small. The list of components proposed by the manufacturer characterizes the device as a low-quality device, since it can not provide proper sensitivity and search accuracy characteristics. Some enthusiasts on the forums are asking to provide firmware for the microcontroller, but more experienced colleagues advise not to repeat the design of the device, since its practicality is rather doubtful.

User Reviews

Reviews of the metal detector Fragma "Terra-N" is quite contradictory. Usually the decisive factor when buying a device is its price. The metal detector Terra-N costs about 6,000 rubles, which makes it affordable even for people with a limited budget. The quality of the device at the same leaves much to be desired. Judging by the feedback of users, for the same money you can buy a homemade device with much better characteristics or a used device of a popular brand.

Reviews on the price of the metal detector "Terra-N", as a rule, end with the fact that people regret about the wasted money. Some recommend throwing a useless device, others - breaking it about the birch, others show the prudence of advice to give the device to the child. In the opinion of real people who bought a metal detector, with its help it is comfortable to look only for scrap metal. The search for coins and valuables usually ends in a fiasco and a spoiled mood. Unsuccessfully saved treasure seekers then buy time-tested appliances and report a completely different level of scanning quality. The device is not recommended even for novice metal detectors, as it can discourage the process as a whole. Knowledgeable people give advice to podkonapit a little money and get a decent device, or pay attention to the devices that were in use.