Which type of sensors are equipped on the smoke detectors?Smoke detectors can have two types of sensors: ionization sensors, photoelectric sensors or both usually called dual sensors. The ionization sensor is used to sense flashing fires by detecting the small particles generated by these fast burning fires and triggering the alarm. The technology behind it involves using a radioactive isotope of americium usually, it’s Americium 241 to ionize the air inside a chamber and, if the sensor detects any changes in the air, it triggers the alarm. The disadvantage of using such type of detectors is that they are more prone to false alarms such as when you’re cooking or when there’s a large amount of steam. The photoelectric sensor is more sensitive to larger particles which are specific to slow burning, smouldering fires which could originate from a forgotten cigarette on the couch, but the sensor is not as sensitive to flaming fires. The way this type of detector works is that it uses a light source can be infrared, ultraviolet or visible which points away from the sensor, but, in the event of smoke entering the small chamber, the light particles will be scattered, therefore, some will hit the sensor and trigger the alarm. This type of technology is used a bit different in larger spaces, where the light beam is directed towards the sensor, but if the intensity of the light drops under a certain level due to smoke, the alarm will be triggered. 2. Does it also have a Carbon Monoxide Electrochemical sensor?Of course, the more sensors, the better, but is it a good idea to have one detector for smoke and Carbon Monoxide or separate units?It depends on the brand trust and the cost. A single unit which has both type of smoke detecting sensors along with an electrochemical sensor is going to be cheaper, it’s going to be easier to install a single unit than multiple ones and maintenance is way easier. But, as they say, it may be a bad idea to put all the eggs in one basket, so, if you go the multiple units route, even if it’s a more costly solution, in case the smoke detector fails, you’ll still have a CO alarm and vice versa.