What are the main devices for issuing air defense alerts?

Air defense sirens are mainly issued using standard equipment such as sound sirensIn wartime, communications, radio, and television systems must give priority to transmitting and issuing air defense warning signalsAuxiliary means such as whistles, horns, bells and gongs can also be used。According to the location of the sound alarm, it is divided into fixed and mobile; According to the energy conversion mode, it is divided into electric type, electroacoustic type, pneumatic type and hand-cranked type.

Air defense warning facilities must be kept in good use, and the issuance and transmission of alarms must be fast and accurate, using a variety of means at the same time; Strengthen communication and liaison with superiors and subordinates and friendly neighbors, receive air raid intelligence information at any time, strengthen the observation of air targets, and report air raid intelligence in a timely manner; Depending on the situation and duration of the air raids, a warning signal will be issued in a timely manner.

With the increase in the suddenness of air raids, the increase in the means of strikes, and the expansion of sabotage intensity, the importance of air defense warnings is being paid more and more attention, and the requirements for the accuracy, timeliness, and continuous issuance of air defense warnings are higher, and the methods of issuing air defense warnings will also become more flexible and diverse along with the construction and improvement of communications and networks.

The electric alarm is composed of main components such as the sound wheel, the fixed wheel, the positioning seat, the positioner, the stainless steel cover, the motor, the base, etc., and there are two kinds of discrete and horizontal electric alarms.

1. Ringing wheel: It is the most important component of the siren, which produces the sound source when it runs at high speed in the work.

2. Fixed wheel: the parts that are highly matched with the sound wheel, usually have about 10 pronunciation windows; The articulation window is equal to the articulation blade of the Narumaki.

3. Positioning seat: the support of fixing the positioner.

4. Positioning device: The sound window can be automatically closed when the ring wheel is not working or after it stops, so as to prevent mice, birds, spiders, and debris blown in the air from entering the siren and play a role in protecting the siren.

5. Stainless steel cover: on the one hand, it is the sound reinforcement effect after sound refraction, and on the other hand, it protects the entire siren to prevent rain from entering the siren;

6. Motor: The power of the siren drives the ringing wheel to rotate and plays the role of sounding.

7. Base: the bracket of the entire siren.

The alarm is driven by the motor to run the sound wheel at high speed, and the general speed is about 2880r min; When the motor drives the ringing wheel to rotate, the air enters the sounding wheel from the side air inlet, and the absorbed air produces high-speed and high-pressure resonance to the window of the fixed wheel at the same time, and the frequency of the sound depends on the instantaneous rotation speed of the motor and the number of vents at the junction of the fixed wheel and the ringing wheel.

**Can't find it. From the description, it can basically be seen that several whistles are mounted on a runner, the motor drives the runner to rotate, and the air blows through the whistle to make a sound, and the tone of the whistle depends on the speed of the runner. The high-low-high tone of the alarm is achieved by controlling the motor speed.

In the past, there was a vertical air defense alarm on the roof of the building opposite the office, which would sound once a year during the city's air defense drill. It was less than a hundred meters away from my office in a straight line, and several buildings around it were shaped like canyons, and the sound was deafening, and the people in the entire office could not talk or work, and they were all in a state of numbness. According to my observations, this thing starts to rotate after being powered on, the tone and volume continue to rise, and when it rises to the highest point, the power goes off, and it continues to rotate by inertia, the tone and volume decrease, and when it drops to a certain extent, it is back on again, and it can produce a high-low high tone by relying on the power switch control.

Maybe the sound of tinnitus will also vary from person to person? The sound of my tinnitus was very high-pitched and thin, much like the sound of the scanning deflection coil behind the picture tube of a television set, compared to the sound of the air raid siren, which was much lower.

"Air Defense Alert" is an abbreviation for "Air Defense Alert Signal". When we usually say "issuing an air defense alert", we actually mean issuing an air defense warning signal.

What are the types of sirens?

According to the energy conversion method, it is divided into four categories: electric, electroacoustic, LED multi-**, pneumatic and hand-cranked siren.

According to the sound pressure of the sound signal, it is divided into large, medium and small sirens. Large sirens have a sound pressure level of more than 100 decibels, medium sirens have a sound pressure level of several decibels, and small sirens have a sound pressure level of a few tens of decibels.

According to the different conditions of use, it is divided into two kinds of fixed sirens and mobile sirens, and the mobile sirens are mainly installed on the car with the air defense siren.

In addition, whistles, wired and wireless radio, television, the Internet, and bells and gongs can also be used as auxiliary equipment and means for alarms.

Under what circumstances will the air defense siren sound?

In peacetime, in accordance with the relevant provisions of the "People's Republic of China Civil Air Defense Law," such as during the "918" period, test sounds may be conducted; In wartime, it is sounded in accordance with the requirements stipulated in the sound signal of the air defense siren.

What should the masses do when the alarm goes off?

Sirens are divided into peacetime and wartime.

The purpose of sounding the air defense siren in peacetime is to better test the intact condition of the city's air defense warning facilities and the sound effect of the siren, so that the broad masses of the public can familiarize themselves with the air defense siren signal and enhance their national defense concept and awareness of civil air defense.

In wartime, when citizens hear air raid warning signals, they should remain calm and listen carefully to what kind of warning signal is being issued, and then take corresponding measures.

In peacetime, the purpose and significance of organizing air defense siren tests.

First, it is to implement the laws and regulations of the state. The "People's Republic of China Civil Air Defense Law" stipulates: "Local people at or above the county level may organize air defense sirens to be sounded according to their needs."

Second, it is aimed at further enhancing the general public's concept of national defense, strengthening the awareness of civil air defense, warning the citizens to be prepared for danger in times of peace, and enhancing their ability to help themselves and each other in the face of war and natural disasters.

Third, the purpose is to inspect the integrity of the air defense warning system, grasp the actual coverage of the warning signal, and scientifically and rationally lay out the air defense siren.

What are the main devices for issuing air defense alerts? The main equipment you ship courtesy of are loudspeakers and sirens. And it's a high-pitched siren.

When the air defense sirens are issued, there are still loudspeakers and the popular ones.

Advance Alert, Air Raid Alert, and De-Alert. Advance alarm, sound mode: 36 seconds, stop for 24 seconds, repeat 3 times for a cycle, the time is 3 minutes, issued when the enemy has a warning of our attack, and require personnel to start evacuating.

Air raid siren, sounding method: sound for 6 seconds, stop for 6 seconds, repeat 15 times. The duration is 3 minutes, and it is issued when the enemy is about to attack us.

Disarming the alarm, purpose: The alarm is sounded when there is an air raid or a temporary easing of the situation. Ringing method: one long tone, continuous sounding for 3 minutes.

Air defense alerts are divided intoAdvance Alert, Air Raid Alert, and De-Alert. These three. Air defense alarm is an important part of urban air defense engineering, peacetime for disaster relief and disaster relief and emergency reporting in the case of sudden accidents, used for civil air defense in wartime, is the basic means for the people at all levels to implement civil air defense command, organize personnel evacuation, is the city is threatened by air raids to remind people of air defense.

Pre-alarm: sound for 36 seconds, stop for 24 seconds, repeat 3 times for a cycle, time 3 minutes. Citizens immediately stopped all work, turned off the power supply at home, turned off the gas, extinguished the fire, closed the doors and windows, carried valid documents, daily necessities and protective equipment, and quickly evacuated to nearby underground air defense shelters, civil air defense projects, and air raid shelters.

Air raid siren: sound for 6 seconds, stop for 6 seconds, repeat 15 times for a cycle, time for 3 minutes. Unable to enter underground air defense shelters, civil air defense projects, and air-raid shelters, citizens take advantage of the terrain to hide nearby, lying on the ground with their hands on their heads.

Lift the alarm: sound a long sound continuously for 3 minutes, and the public can get out of the underground air defense shelter, civil air defense project, and air raid shelter and resume normal work.

Air defense alarm is an important part of urban civil defense projects, and it is the basic means for people at all levels to implement civil air defense command and organize personnel evacuation. In war, when a city is threatened by air raids, air raid sirens are used to alert people to take refuge in the air raid; In peacetime, it is used for disaster relief and disaster forecasting and emergency notification in the event of an emergency, and in addition, air defense alerts are also used at specific times and places to commemorate certain major events.

There are three types of air defense alarms, which are divided into advance warning, air raid warning, and disarming alarm.

Air defense alarm is an important part of urban air defense engineering, peacetime for disaster relief and disaster relief and emergency reporting in the case of sudden accidents, used for civil air defense in wartime, is the basic means for the people at all levels to implement civil air defense command, organize personnel evacuation, is the city is threatened by air raids to remind people of air defense.

The purpose is to enable the people's air defense organs and professional contingents to take timely action in accordance with the plan, so that the people can evacuate and conceal themselves in a timely manner, reduce the loss of people's lives and property, maintain the war potential, and strive for victory in the struggle against air raids.

1. Pre-warning signal: sound for 36 seconds, stop for 24 seconds, 3 times for a cycle (time 3 minutes). When the alarm sounds, the public should immediately stop all work, close the doors and windows, cut off the power supply, extinguish the fire, turn off the gas, liquefied gas, etc., carry valid documents, daily necessities and personal protective equipment, quickly evacuate and orderly go to the nearby underground air defense shelter, civil air defense project, air raid shelter or designated hidden area.

2. Air raid siren signal: sound for 6 seconds, stop for 6 seconds, 15 times for a cycle (time 3 minutes). When the air raid sirens sound, enemy planes or other air raid weapons are already approaching the sky over the city, and the air raid operation is about to be carried out or has already begun, informing people to quickly evacuate, shelter and other protective measures.

When it is impossible to enter underground air defense shelters, civil air defense projects, air raid shelters and other hidden areas, citizens should immediately use the terrain to hide nearby, lie on the ground with their heads in their hands, and prevent air raids.

3. Disarm the alarm signal: sound a long tone, and sound continuously for 3 minutes for a cycle (time 3 minutes). When the sirens are lifted, the air raids or the fighting situation are temporarily eased, and citizens should return to their homes or jobs in an organized and orderly manner, and at the same time, normal production and life in the city can be restored.

If there is a collapse of houses, fires and personnel caused by air raids, it is necessary to actively carry out actions such as self-rescue, mutual rescue, fire extinguishing and emergency repair under the unified organization of the unit or community.

Many cities will conduct air defense sirens on a certain day every year, the time is generally 15 minutes, in accordance with the order of the advance alarm, air raid siren and the alarm is sounded, and the test will be announced on the news before the test, so as not to cause panic among the public. The air defense siren test is to mourn the people who died in the air raids, to test whether the civil air defense equipment is intact and to cover the situation, and third, to carry out national defense education, enhance the national defense concept of the general public, and improve the ability to help themselves and each other in response to wars and natural disasters.

First, the warning alarm, sound for 36 seconds, stop for 24 seconds, repeat 3 times for a cycle, the time is 3 minutes; Second, the air raid warning, sounding for 6 seconds, stopping for 6 seconds, repeating 15 times for a cycle, the time is 3 minutes; Third, disarm the alarm and sound a long sound continuously for 3 minutes.

Warning: 36 seconds tomorrow. Stop for 24 seconds. Repeat three times for a cycle.

Air Raid: Ring for 6 seconds, stop for 6 seconds, repeat 15 times for a cycle.

Contact Alert: Sound for three minutes.

Air defense alarms are divided into electric alarms, electroacoustic alarms, and hand-cranked alarms, which are used to remind people of air defense evacuation, and will be used for evacuation and anniversaries in emergencies.

There are three types of air defense alerts, which are pre-alert, air raid alert, and de-alert. We can distinguish according to the characteristics of their horns, the early alarm is to sound for 36 seconds, stop for 24 seconds, repeat 3 times for a cycle, the time is 3 minutes. The air raid siren is sounded for 6 seconds, stopped for 6 seconds, and repeated 15 times for a cycle of 3 minutes.

There is also a long sound that blows continuously for 3 minutes.

The air defense alarm is mainly used for civil air defense in wartime, when the outbreak of war is threatened by air raids, the air defense alarm can remind the people to take refuge in a safe environment in time. In non-war times, air raid warnings can also be used to predict sudden and dangerous situations for disaster relief and disaster relief.

People who have recently watched the movie "Eight Hundred" know that in war, air strikes are suppressive and devastating to the combat effectiveness of ground activities. Whether armed with machine guns or fighter jets armed with bombing bombs, striking a living force on the ground is as simple as a three-dimensional human destroying a two-dimensional ant. In the battle with Saddam, the US military also adopted the method of bombing from the air and then sending ground troops to attack.

It can be seen that although it has been 75 years since the end of World War II, air strikes are still a very effective means of combat power. In the face of a sudden air strike, the role of air defense alerts is particularly important. Despite the suddenness and rapidity of an air strike, it does not mean that it is undetectable.

When the enemy forces send out air strikes in wartime, air raid sirens can alert combat troops and civilians to take shelter and minimize the damage of air strikes.

But someone will say that our country is not in a state of war, and whether the air defense alert still needs to be maintained. Such a statement is just as the war is gone, and the respect for the martyrs of the war and the veterans of the war must continue. Despite the efforts of the Chinese nation over several generations, the Chinese nation has finally won the victory of the new democratic revolution and has achieved remarkable results in reform and opening up.

But remember that history is always a lesson left to us by wars and martyrs. Every year on September 18, air raid sirens are sounded all over the country, so that each generation can remember the history of aggression and the backward years. Only in this way can every progress we make today have a basis for a foothold, and every achievement we make will be meaningful.

Air defense sirens can become a clarion call to protect people's lives in wartime, and they are also the memory of war that should not be erased in our hearts in peacetime.