What's flashing red on the ceiling of the hotel?

This is a smoke detector, which is used to put out fires.

Smoke detectors can prevent fire by monitoring the concentration of smoke. The ion smoke sensor is used in the smoke detector. Ion smoke sensor is a kind of sensor with advanced technology and stable and reliable work, which is widely used in various fire alarm systems, and its performance is far superior to gas-sensitive resistance fire alarm.

It has radioactive source americium 24 1 in the inner and outer ionization chambers, and the positive and negative ions generated by ionization move to the positive and negative electrodes respectively under the action of electric field. Under normal circumstances, the current and voltage of the inner and outer ionization chambers are stable.

Once there is smoke, the ionization chamber outside will disappear quickly. If the normal motion of charged particles is disturbed, the current and voltage will change, which will destroy the balance between the inner and outer ionization chambers. So the wireless transmitter sends out a wireless alarm signal to inform the remote receiving host and send alarm information.

Extended data:

Commonly used smoke detectors are divided into two types: ion smoke detectors and photoelectric smoke detectors.

1. Ion smoke detector uses smoke particles to change ionization current in ionization chamber to detect surface alarm signal. There are two kinds of photoelectric smoke detectors: dimming photoelectric smoke detector and scattered light photoelectric smoke detector. They use the absorption and scattering of light by smoke to change and excite signal current, thus generating alarm signals.

2. Working principle of dimming photoelectric smoke detector: smoke particles entering the dark area of photoelectric detection absorb and scatter the light emitted by the light source, so that the luminous flux passing through the light path is reduced, thereby reducing the photocurrent generated on the light receiving element. The change of photocurrent relative to the initial calibration value reflects the concentration of smoke. When the concentration of smoke particles reaches a certain value, the energy of scattered light is enough to generate a certain amount of photocurrent for excitation, which can be used to give a fire alarm to external circuits.

Baidu encyclopedia-smoke detector

Baidu encyclopedia-smoke detector