A co meter monoxide, an odorless, colorless, tasteless gas. It samples the air for CO molecules and a microprocessor keeps track of the data, alerting you only when cumulative exposure exceeds a safe level. It’s easy to make a sensor that senses CO but requires complex sensors and microcircuitry to reliably track minute fluctuations over time and sound the alarm only when they indicate danger.

Carbon monoxide combines with hemoglobin in the blood and renders it incapable of carrying oxygen to body tissues, including the brain and heart. This can lead to poisoning and death. A CO detector or meter is an essential safety device for households with fuel-burning appliances. It should be installed in the home, especially upstairs hallways where people might pass and within 5 feet of boilers and furnaces. It should be tested regularly, at least every spring and fall.

Breath of Fresh Air: How Carbon Monoxide Meters Keep You Safe from Invisible Danger

Most CO detectors have an alarm that sounds when concentrations reach a dangerous level. Some units also have a display that shows the CO concentration, usually in parts per million (ppm). Some meters can be connected to a system that monitors CO levels and alerts a monitoring service.

Industrial hygienists and first responders use portable CO meters to test for leaks and assess the level of exposure to occupants. These units are more sensitive than the UL2034 home ceiling mount CO detectors and are designed to measure CO concentration down to a few ppm, much lower than alarm-tripping concentrations. They are used for testing and tracing of a leakage path and are often battery powered.