How Does a Carbon Monoxide Sensor Work?

Metal Oxide Semi-Conductor Sensors

There are three basic types of carbon monoxide sensor that are most commonly used today. While each one is effective in and of itself, each one also works under a different process than the others. The first ever invented carbon monoxide sensor is called a metal oxide semi-conductor (MOS) sensor. A MOS sensor contains heated tin oxide (or other metal oxides in some more recent sensors), and the interaction of carbon monoxide gas with the heated tin creates a temperature change that is related directly to the toxicity level of the carbon monoxide that's present. The sensor then sounds an alarm when the level is too high, provided that the sensor is plugged into the power of the house, or is currently operating off its own battery pack. More often than not though it's one or the other option for power with these sensors, not both.

Biometric Sensors

The second, and slightly more popular type of carbon monoxide sensor, is called a biometric sensor. This sensor uses a disk that is coated in a gel that will darken in color in the presence of carbon monoxide. The sensor monitors the disk, and then when the color of the disk changes, the sensor will sound the alarm. These sensors are simpler from a technological perspective, but they still require either a battery pack or to be plugged into a wall socket. It's their simplicity, and the absence of a heated metal oxide, that makes them more popular than the original MOS sensors.

Electrochemical Sensors

This is currently the most common type of carbon monoxide sensor in use. When this kind of sensor detects levels of carbon monoxide, it triggers an electrical current that sets off the alarm. These sensors are accurate at a variety of carbon monoxide levels, and many of them include a constant readout on the front as well as a memory feature that lets you check for carbon monoxide build-ups over time. Ideally, this is the sensor most homes and businesses would use, but due to the relative complexity, electrochemical sensors are also more expensive than the previous two types of sensors. However, you gets your money's worth with the sheer amount of options that it presents to monitor your home's carbon monoxide level and relative safety.