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  Revealing the principle of natural electric field ground water detector to measure water

Views: 5     Author: pqwt     Publish Time: 2022-10-11      Origin: PQWT

The natural electric field ground water detector uses natural electromagnetic waves to measure water. The propagation law of electromagnetic waves in the ground is different from the propagation law of electric current in the ground used by the resistivity method. The resistivity method follows the flow network principle, electromagnetic waves follow Maxwell's equations.

ground water detector


For the resistivity method to measure bedrock fracture water, although the resistivity of water is smaller than the resistivity of rock, but the two compared, water accounts for a much smaller weight than the weight of rock (hard rock fracture rate is mostly 1-5%), the resistivity of the two weighted average of the resulting composite resistivity value is mainly a reflection of the resistivity value of a large value of rock. So hard rocks, whether or not they contain water, resistivity is very large. We use resistivity method to find water research for decades, most of the bedrock fracture water is not easily reflected, the effect is not satisfactory.



Electromagnetic wave measurement of water why the reflection of water is more obvious, more intuitive? This needs to be said from the shielding ability of different substances to absorb electromagnetic waves. Various substances shield the ability to absorb electromagnetic waves differently, this ability is called "shielding effectiveness". In non-metallic substances, water is the strongest shielding and absorbing ability of electromagnetic waves. The stronger the ability to absorb electromagnetic waves can impede the spread of electromagnetic waves. Water molecules can consume part of the energy of electromagnetic waves, if it is very weak electromagnetic waves will be completely dissipated in the water, it can also be said that to a certain extent, the electromagnetic waves down the propagation. Water molecules are very polar molecules, water is a very polar polar material, or water is very strong ability to absorb electromagnetic waves. When a part of the rock below the ground has a large fissure containing water, the water absorbs electromagnetic waves, and this point becomes a low value point.



Shielding effectiveness from large to small is divided into 6 levels, in decibels db. electromagnetic waves in seawater attenuation is very serious, the higher the frequency of electromagnetic waves in seawater attenuation is greater. Underwater experiments show that: the ordinary emission of radio waves underwater can only spread about 1 meter, low-frequency long-wave radio waves can reach 6-8 meters, and ultra-low-frequency electromagnetic waves on the seawater penetration capacity of only more than 100 meters. Using this reasoning, we can also use the natural electric field ground water detector to distinguish whether the groundwater is salt water or fresh water. The saltier the water, the faster the attenuation of electromagnetic waves, the lower the value of sky electricity.



Microwave heating is also the use of electromagnetic waves, only the frequency is different. Food containing water with it is easy to heat, but dry matter is more difficult to heat, the reason is that the water is absorbing electromagnetic waves, no moisture absorption of electromagnetic waves of the material is much weaker, not easy to heat. Pure metal is different from water, to be precise, it is not mainly absorb electromagnetic waves but reflect electromagnetic waves, so it is difficult to heat the metal with a microwave oven. Underground steel pipe reflects electromagnetic waves as a result, so that electromagnetic waves also can not be propagated downward, in the sky electrogram will also show a low value.



Why does water absorb electromagnetic waves? This is because, water molecules are polar molecules (i.e., the positive and negative charge centers of individual atoms in the molecule do not overlap, and the charge distribution is asymmetric). Water is a polar molecule because it is formed by two hydrogen atoms and one oxygen atom, and the angle of the two hydrogen atoms is about 109 degrees. This means that the centroids of the two hydrogen atoms do not coincide with the centroid of the oxygen atom. The ability of the oxygen atom to attract electrons is much greater than that of the hydrogen atom, and the electrons on the oxygen-hydrogen bond are more favorable to oxygen. The center of gravity of positive and negative charges in water molecules are far apart, so water has a large polarity. Electromagnetic waves are high-frequency oscillations, in this high-frequency oscillation of water molecules will vibrate, so that the kinetic energy increases. Increased kinetic energy will reduce the energy of electromagnetic waves, which can also be recognized as electromagnetic waves are absorbed into the heat, so the food is heated.



Electromagnetic wave propagation in the underground, when encountering bedrock fracture water, electromagnetic waves are absorbed, the value decreases, becoming a low value, downward propagation ability is reduced, there will be a low value of downward transmission. As long as we can exclude the non-structural low-value downward transmission of false anomalies, the probability of low-value "anomalies" in hard rocks with water is very high.



This property of electromagnetic waves is not present in the resistivity method, which reflects more the electrical conductivity of the rock skeleton than the shielding and absorption capacity of water. This is the reason why the natural electric field ground water detector is more sensitive to water bodies.


ground water detector

Most of the rocks with fracture water are reflected by lateral or vertical low value anomalies, but the low value without anomalies does not necessarily have fracture water. Soil layers, soft rocks or strongly weathered layers show low values because they contain more mineral water. These rocks and soils do not have high values of sky electricity not because of its small resistivity, but because it contains more mineral water in its mineral composition. For example, kaolinite in clay minerals has the crystal formula 2SiO2-Al2O3-2H2O and contains two crystalline waters. Hard rocks with high resistivity often also form low value layers, also because of the high content of mineral water such as crystalline water or structural water. For example, hornblende is a chain structure silicate containing (OH) Mg, Fe, Ca, Na, Al. OH is not a hydroxide root here, but the usual expression of structural water, and the water is separated out when it is heated to 600 degrees or more.



It can be seen that, under the certain electromagnetic environment, the low value anomaly and the size of the value of the sky electrogram are mainly determined by the "water" in the stratum and minerals, rather than the resistivity of the rock and ore, which is the reason why the natural electric field ground water detector has higher resolution and more intuitive reflection of bedrock fracture water. This is why the natural electric field ground water detector has higher resolution and more intuitive reflection of bedrock fracture water.


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PQWT is a professional institution in China who engaged in the R & D, manufacturing and sales of underground water detector, water leak detector, leakage automatic analyzer, cavity detector, mine locator, dam piping detector, and borehole inspection camera. 

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