Estimated the arrival of lightning
While listening carefully and watching the weather forecast, you can also estimate the coming of lightning through your senses.
(1) Looking up at the sky: When the dense dark clouds (cumulant clouds) in the sky begin to accumulate and become darker and develop faster, lightning may occur.
(2) Listening to noise: When you turn on the radio and listen to the radio, if you hear a harsh noise, it means there may be a lightning cloud in the vicinity (however, be careful to distinguish it from nearby electromagnetic interference).
(3) Estimated distance: The easiest way to judge when the lightning will reach the local is that when the lightning is seen, the second reading is immediately, because the speed of light is 300,000 kilometers per second and the speed of sound in the air is 340 meters per second. The difference, therefore, there will be a certain time difference between lightning and the accompanying thunder. If you see the time interval between lightning and hearing thunder is 5 seconds, it means that the lightning flash occurs about 1.5 kilometers away from yourself; if it is 1 second, it will be heard in a blink of an eye. , indicating that the lightning flash position is about 300 meters nearby. When encountering thunderstorms, remember that each time you hear thunder and see lightning, the time interval is getting longer or shorter, or getting shorter and shorter, to judge whether the thunderstorm is gradually moving away or getting closer. Therefore, take certain precautions.
(4) Self-feeling: When you feel your hair is erected or the skin feels different, it is likely to be struck by lightning. At this time, take immediate measures to protect yourself.
Outdoor lightning protection
Summer is the season of lightning. If you are in the wild, or when you encounter thunderstorms on the road, if you take some measures in time, you can minimize the possibility of being hit by lightning.
(1) In the wild, especially on the road, pay attention to listening, watching or surfing the Internet to check the weather forecast, and see if there is lightning weather.
(2) When a thunderstorm occurs, it should be quickly hidden in a building protected by lightning protection devices, or in a deep cave. The car is an ideal place to escape from lightning strikes. If you are swimming or on a small boat, you should land immediately, even on a large ship, and you should hide in the cabin.
(3) When the wilderness is unable to hide in a building with lightning protection facilities, keep away from tall, isolated objects such as trees, telephone poles, and chimneys. It is not advisable to stay near iron fences, metal clotheslines, overhead metal bodies and railroad tracks. It is not advisable to enter low-rise buildings such as wild shacks and guard posts without lightning protection devices. Keep away from transmission and distribution lines, overhead telephone cables, etc. Try to avoid small areas that are particularly prone to accumulation, such as rock faults, larger rock mass cracks, ground exits of buried pipelines, and so on.
(4) When the top of the head is flashing and thundering (commonly known as “explosive mine”), if you can't find a suitable lightning protection site, you should find a place with low terrain, try to reduce the center of gravity and reduce the contact area between the human body and the ground. Put your feet together, put your hands on your lap, bend forward and temporarily avoid them. Don't lie on the ground. If you can put on a raincoat, the lightning protection effect will be better. Be careful not to get together or hold hands together.
(5) Do not use metal-tip umbrellas in open spaces. Do not put tools such as shovel and golf clubs on your shoulders. When you are under lightning protection, it is best to take off the metal objects and put them away from the distance of a few meters. In particular, take the metal frame glasses that you wear.
(6) Do not swim or engage in other water sports and homework. For example, in rice fields, it is not advisable to carry out outdoor sports, climbing, riding, etc., and leave the water surface and other open space as soon as possible to find places with lightning protection devices to avoid.
(7) It is not advisable to drive a motorcycle or ride a bicycle to catch a road.
(8) In the event of an unfortunate lightning strike, the companion should promptly call for help, while doing artificial respiration and extracorporeal heart massage for the wounded or the fake.
Indoor lightning protection essentials
When lightning strikes, it is safer to hide indoors, but it is only relatively indoors. If you do not pay attention to taking measures indoors, in addition to being directly attacked by spherical lightning, it is more likely to suffer from indirect lightning strikes.
Lightning protection measures:
(1) Be sure to close the doors and windows
(2) Try to stay away from metal doors and windows, metal curtain walls, and places with power outlets. Do not stand on the balcony.
(3) Do not approach indoors, and do not touch any metal pipelines, including water pipes, heating pipes, gas pipes, etc.
(4) If there is no lightning protection device in the house, it is best not to use any household appliances indoors, including TV sets, radios, computers, wired phones, washing machines, microwave ovens, etc. It is best to unplug all the power plugs.
(5) Special reminder: Do not use solar water heaters for bathing in thunderstorms.
(6) If you are inadvertently subjected to lightning strikes, you should take timely rescue measures.
Building lightning protection measures
With the rapid development of modernization and the advent of the information technology era, the emergence of high-rise buildings and the extensive use of electrical equipment and electronic equipment, the threat posed by lightning has become increasingly serious.
1. Adopt comprehensive lightning protection technology, and carry out lightning protection engineering as system engineering for standard design, careful construction, strict acceptance, regular maintenance, and regular inspection to ensure the lightning protection device is safe and effective.
2. Regular inspection is necessary for the post-maintenance of lightning protection equipment. At least every year before the arrival of the thunderstorm season, the statutory inspection technology will conduct a comprehensive inspection of the lightning protection device and evaluate the safety performance of the lightning protection device. In order to use the unit to develop the corresponding lightning disaster emergency plan.
3. The unit shall set up persons responsible for lightning protection disasters, be responsible for lightning safety work, establish various lightning protection safety work, establish regular inspections of various lightning protection devices, inspection after thunderstorms and daily maintenance. After the thunderstorm, if the lightning protection device is found to be damaged, it should be replaced in time.
4. During the design and construction of the lightning protection device, the construction unit shall adopt a safe and reliable, advanced technology and economical design and construction plan based on the characteristics of geology, rustic image, environment, the characteristics of the protected object, and the laws of lightning activity. .
5. Lightning protection products whose technology and quality are in line with national standards should be used to avoid the use of counterfeit lightning protection products.
6. When rebuilding or expanding buildings or adding new equipment, consideration should be given to redesigning and constructing the original lightning protection devices, such as: re-laying computer network lines, shifting and heightening of outdoor antennas, etc. The lightning protection device was redesigned and constructed.
After the occurrence of a lightning disaster, the situation should be reported in time for investigation and treatment to avoid another lightning strike.
How to protect against solar water heaters
Solar water heaters, as the name suggests, are devices that use the principle of solar heating to obtain hot water. With the development of science and technology, solar water heaters are deeply loved by consumers because of their novelty, environmental protection, energy saving and convenience, and the number of installations has increased year by year. In order to collect heat, people are accustomed to install solar water heaters on sunny places on the roof, and this installation often exceeds the height of the original lightning protection device on the building, so that it is completely exposed to lightning strikes, and has built-in The electric heating power line and the sensing signal line pass through the room, and its metal components are more. In fact, the water heater becomes a lightning receptor. Once the building is struck by lightning, the water heater is often the object of “beating”. Moreover, part of the lightning current will directly enter the user's room through the pipeline, power line and signal line of the water heater, thus bringing lightning safety risks, such as not taking scientific and effective. Lightning protection measures will cause water heaters and household appliances to burn down, and there will be explosions, fires or casualties.
(1) A more reliable method is to install the water heater within the protection range of the lightning protection belt (needle).
(2) Take lightning protection measures for solar water heaters, and the specific design and construction should be completed by professionals.
(3) If the lightning rod cannot be installed, the water heater should be connected to the original lightning protection device on the roof. It is recommended not to use the solar water heater when thundering.
Lightning damage to the human body
Direct lightning strike
The so-called direct lightning strike means that the lightning strikes directly hit the victim. In this case, the victim passes all the lightning current at least at the beginning, and the maximum is that the lightning current is input from the head, through the trunk, and from the sole of the foot into the earth. This situation is the case in which the victim suffers the most. Therefore, there are many cases in which direct lightning strikes have resulted in the success of suspended animation. Even after a direct lightning strike, there is a brief coma, and there are reports that the breathing and heartbeat have not stopped. So when the lightning strikes to death, the breathing stops, the heart stops beating, but the body does not When purple-blue patches or spots appear, you should not give up or stop the rescue.
Contact lightning strike
Contact lightning strikes are lightning strikes on other objects that cause the person touching the object to become a victim. Contact with lightning strikes often causes the victim to be paralyzed for a short period of time, sometimes coma or even death, but in general it is less harmful than direct lightning strikes. The probability of contact lightning strikes is much higher than direct lightning strikes.
The side flashover and the contact lightning strike mentioned above are all that the lightning does not directly hit the victim, but hits the object near the victim. Due to the high potential of the lightning strike, the lightning strikes the person nearby. Sometimes, due to the lightning strike of objects in far away places, the high-potential can be directly transmitted through the metal wire, or the high potential is induced to cause side flashover to cause casualties.
The stride voltage is when the lightning current flows into the earth, due to the existence of the soil stray resistance, the surface potential distribution is used, which is customarily called the horn-shaped potential distribution curve. There is a potential difference between any two points on this flare curve. Obviously, this potential difference is related to current intensity, soil resistivity distribution, and step length. In the same soil condition, the current intensity is larger, the step size is larger, and the step voltage is The higher. When a person or an animal stands on the ground with a horn-shaped potential distribution, when the potential difference between the two feet is large enough, it is enough to cause an electric shock or even death. If you encounter a thunderstorm in the wilderness and you can't avoid it, kneel down and shrink your feet to a point, it will be safer than striding.
Lightning electric burn and its emergency treatment
The electrical heat effect of lightning strikes on the human body can cause electrical burns. However, electric burns are different from general burns. There are still electrical shocks such as loss of consciousness, dizziness, nausea, palpitations, tinnitus, and fatigue. In severe cases, breathing and sudden cardiac arrest can occur. There are also cataracts and nervous system damage that occur later after lightning strikes.
(1) If the lightning striker's clothes catch fire, you can wave water on your body, or wrap your body with a thick coat or blanket to extinguish the flame. Don't run scared by the fire, you can roll on the ground to put out the flame, or squat in the water and the pool to extinguish the flame.
(2) Pay attention to the phenomenon of unconscious loss and respiratory and cardiac arrest caused by lightning strikes. First, rescue the cardiopulmonary resuscitation, and then treat the electric burn wound.
(3) Treatment of electric burn wounds, cool the wound with cold water, and then cover the dressing. For example, cover the wound on the wound and wrap it with a clean cloth. If no dressing can be used to clean the sheets, sheets, clothes, etc., the injured person will be wrapped and transferred to the hospital.
In principle, the injured should be transferred to the local hospital. If the local unconditional treatment needs to be transferred, the delivery time should be mastered, the injured person should have a clear airway, no active bleeding, the shock should be basically controlled, the infusion should be infusion, and the measures should be taken. And pay attention to reduce bumps on the way.