Audit expert: jianjin
Ph. D., china institute of meteorological sciences
Have you ever thought about the lightning in the weather: why are trees, especially in the open, always vulnerable in thunderstorm weatherThunderHit leads to a break or fire, and some topsBuildingsHow can you stand up and be safe when lightning strikes? Is it just because buildings are stronger than trees
To answer that question, we can't stop talking about a "god" that's common in our livesA lightning rodI don't know. So how does a lightning rod avoid a mine? Did you install a lightning rod and the lightning will avoid the building? Let's go down。
Mine-shielding needles on buildings
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The work of the lightning rod
There is now a clear understanding of the rationale for lightning rods, which typically consist of the earth's body, the ground's downline and the three-part transient. Typically, a flasher uses a round steel or steel tube with a length of 1-2 m and a diameter of 15-20 mm, which is fixed at the upper end of the pillar and is connected to the earth's cortex by a straight line。
When it comes to rain and snow, a number of high-level buildings are able to detect large amounts of positive charge in the cloud layer. When a thunder cloud discharges near the ground, it causes a deformation of the ground field. During this brief discharge, which was struck by lightning, huge electrical energy was transformed into light, heat, and so on, causing damage to buildings。
The doctrine of lightning rods
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Because of the sophisticated design of the top of the lightning rods, when electrostatic rods are fired, there is a large amount of charge, and between the lightning rods and the clouds they form a capacitor, which forms a circuit with the electric cloud layer, thus actively attracting lightning to discharge the rods。
When a lightning rod is installed higher than the building, it is particularly powerful at the point where it is used because of the cutting-edge discharge effect, and only between the cloud layer and the lightning pin, thereby effectively preventing damage to the building by lightning。
The role of a lightning rod
Through this brief introduction, we can see that the true function of lightning rods is not mine avoidance, but mine diversion. The installation of detonators and associated mine-protecting facilities in the building has two main functions。
The first was to protect against direct lightning: it was mainly to avoid lightning hitting buildings directly. For example, some high-rise buildings must be equipped with lightning rods or other mine-protective facilities to mitigate the massive electrical currents generated by lightning strikes into the land along buildings and to reduce the damage caused to the inner space of buildings。
The second was the protective sensor: the sensor was an electromagnetic sensor that had been used by the lightning on the metal line of the building, and damage had occurred to electrons, mainly to protect household appliances and weak electrical equipment. In addition, the installation of leak protections can also serve to protect household electricity, while it is important to be mine-proof。
If thunder strikes occur on a concrete pillar on the floor, the current may be transmitted to the ground along the metal inside the building。
Without the necessary mine-protective measures on the living floors, the energy generated by lightning currents cannot be effectively released, and there is a risk that it will pass through the floors, causing some direct or indirect damage to the buildings or the electrical systems of the floors。
Therefore, in the event of thunderstorms, it is important that indoor appliances be careful to cut electricity in a timely manner so as to effectively protect people's lives and property。
It's raining
The source, the fox
Mine-shield technology was applied in ancient times
Finally, it is worth mentioning that the chinese ancients have applied mine-proofing techniques in practice。
Tandai's book, " the bronze house in han dynasty " , documented a fire and suggested putting a fish-tailed copper balconies on the roof, which could prevent a thunderstorm from burning. The metal decorations of the fish tail shapes of the roofs referred to here actually have the effect of shielding from mines, which can be considered as the prototype of modern detonators。
The french traveler, gabrielobe de magangan, in his 1688 book " china's new news " , wrote that at both ends of the back of the chinese house there was a head on the back of the roof, that the dragon's tongue sprang out of twists and pieces of metal, and that the tongue was connected to a tiny wire that went straight underground。
Such a wonderful device can act as a shield against lightning at the moment of its occurrence, preventing it from destroying the building; if the lightning hits the house, the current will flow from the dragon's tongue to the ground along the wire, avoiding direct lightning。
This suggests that the mine avoidance devices in ancient chinese buildings are already largely similar in principle to modern detonators。
Many of our ancient buildings have survived, owing in large part to the use of mine avoidance techniques in these ancient buildings, such as tashas on the guta and fjords on the ancient buildings。
The tower's towers are capable of producing a stronger current of electroshock in the lightning field, thus acting as a shield against mines; and for the ancient buildings, the head of a copper beast or a copper balconies are placed on each of the corners, and are connected through the copper line to the ground for peace。
Although the ancients did not understand the rationale for the lightning rods, they did not consciously use the lightning rod technology, which was the culmination of years of experience and wisdom of the ancients。
China's ancient construction mine avoidance measures: tasha and fjords
