There are two main types of smoke detectors used in residential buildings: one is the ionization smoke detector, which has an ionization chamber, which is in the equilibrium state of the electric field under normal conditions. When smoke enters the ionization chamber, it will destroy the ionization chamber balance, an alarm will be generated. When the unbalance reaches the pre-set level N=9.5%/m, the alarm will sound. The other is called a photoelectric smoke detector, which has an optical maze with a pair of infrared tubes inside. Under normal circumstances, the infrared receiving tube cannot receive the infrared emitting tube. Infrared light, when smoke and dust enter the optical labyrinth, through refraction and reflection, the receiving tube can receive the infrared light, thus sending out an alarm signal.

Each smoke detector meets the standards required for safety, but each has its own strengths. Ionization smoke detectors are quicker at sensing tiny smoke particles, while photoelectric smoke detectors are quicker at sensing larger smoke particles. When a raging fire occurs, there are more tiny particles of smoke in the air, while when a smoldering fire occurs, there are more larger smoke particles in the air. The researchers found that if a fire breaks out and produces a large amount of tiny particles of smoke, the ionization smoke detector will alarm before the photoelectric smoke detector. The time interval between these two types of smoke detectors is not large, but this type of fire spreads very quickly. In such places, it is recommended to install ionization smoke detectors. In the other category, after a smoldering fire occurs, a large number of slightly larger smoke particles are produced, and the photoelectric smoke detector will alarm before the ionization smoke detector. In such places, it is recommended to install a photoelectric smoke detector. If you want the best of both products, you can install both types of smoke detectors where required.

If an ionization smoke detector is installed in the kitchen, since the ionization smoke detector is sensitive to small particles, the ionization smoke detector will quickly alarm when cooking. If you have ever encountered this problem, you have a few options:

1) Install the ionization smoke detector farther away from the cooking, then the ionization smoke particles will be much weaker when they reach the alarm. If you choose this method, you should figure out the direction of the air flow, you must stay away from the path of the air flow, otherwise it will not work.

2) Instead of installing an ionization smoke detector, install a photoelectric smoke detector. When a fire occurs with smaller particles, you may lose the opportunity to alarm earlier, but you also save the trouble of false alarms from the ionization smoke detector.

3) Install a combined ionization/photoelectric smoke detector. If the two sensors are combined, the sensitivity of the ionization sensor can be set to be less sensitive, so that the device will reduce false alarms, and you can also have a fast spreading fire and a slow spreading smoldering fire, both smoke detectors with greater sensitivity.

4) Install an ionization smoke detector with a rest button. This way you can stop the false positives for 15 minutes, giving you enough time to move the source of the false positives away, this method is not as simple as the methods mentioned in 2) and 3) above, but it gives you enough time to remove the battery from the ionization smoke detector.