How Smoke Sensors Work There are several types of smoke sensors

Smoke sensors are widely used in places where there are gas and coal dust explosions and fire hazards. By monitoring the concentration of smoke to prevent the occurrence of danger, the monitoring is stable and reliable. So what is the working principle of the smoke sensor? What are the classifications of it? Xiaobian will give you an introduction in the following.

Smoke sensor works

When smoke from the sensor enters the monitoring ionization chamber, the detection source 241 in the ionization chamber emits a-rays, so that the air in the ionization chamber is separated into positive and negative ions. When the smoke enters, the ion currents in the inner and outer ionization chambers are kept in a state of equilibrium due to the opposite polarity. The aerosol submicron particles and visible smoke released in the early stage of the fire enter the detection chamber and absorb and neutralize the positive and negative ions. The ionization current is drastically reduced, and the ionization balance state is changed and the detection electric signal is output. After processing and recognition by the latter stage circuit, an alarm is issued and an alarm switch signal is output to the supporting monitoring system.

Smoke sensor classification

1. Ionic smoke sensor

The smoke alarm uses ion smoke sensor inside, and the ion smoke sensor is a kind of advanced technology and stable and reliable sensor. It is widely used in various fire alarm systems, and its performance is far better than that of gas-resistance fire alarms. .

2. Optical smoke sensor

The photoelectric smoke alarm has an optical labyrinth with an infrared tube installed. The infrared receiver tube does not receive the infrared light emitted by the infrared emission tube when it is smokeless. When the smoke enters the optical labyrinth, it receives the infrared through refraction and reflection. Light, smart alarm circuit determines whether the threshold is exceeded, if it exceeds the alarm.

3. Gas sensitive smoke sensor

A gas sensor is a sensor that detects a specific gas. It mainly includes semiconductor gas sensors, contact combustion gas sensors and electrochemical gas sensors, among which the semiconductor gas sensor is the most widely used. Its applications include: detection of carbon monoxide gas, detection of gas, detection of gas, detection of Freon (R11, R12), detection of ethanol in breath, detection of oral halitosis, and the like.

It converts the gas species and its concentration-related information into electrical signals. Based on the strength of these electrical signals, it can obtain information on the presence of the gas to be measured in the environment so that it can be detected, monitored, and alarmed. The automatic detection, control and alarm system can be composed of interface circuits and computers.

The above content is the working principle and classification of the smoke sensor. At present, the smoke sensor is also widely used in households, and plays an important role in the family fire prevention. It avoids or reduces the casualties and minimizes the property damage caused by the fire.

related suggestion:

Article: Difference between Ionic Smoke Sensors and Photoelectric Smoke Sensors

Recommended: Shenzhen password lock 800 smart lock quality smart lock