How to Use a Portable CO Detector

Carbon monoxide is an odorless, colorless gas produced by furnaces, stoves, fireplaces, generators, vehicles and other fuel-burning devices. It can seep into poorly ventilated spaces or get trapped in the home, and poisoning at levels higher than 70 parts per million can cause headaches, dizziness, weakness, nausea and loss of consciousness. The elderly, children and those with lung or heart problems are at particular risk.

A portable co-detector can warn of possible danger in your car, hotel room, cabin or tent, but you need to know how to use it properly. The best models use a sensor similar to the one found in your home: Thin wires of semiconductor tin dioxide on an insulating ceramic base are heated; oxygen increases the resistance, while carbon monoxide decreases it. The sensor is monitored by an integrated circuit; alarms sound when levels exceed a predetermined threshold.

Some models come with a digital display that indicates CO levels and alerts you when the readings reach unsafe levels. Others are a little simpler: They have an LED light and sound a buzzer when levels exceed WHO, EPA, ASHRAE and OSHA recommendations. A few have a removable lanyard, so you can clip them onto your keychain or carry them in your bag.

Portable CO Detectors: Your Safety Companion on the Go

Most portable CO detectors are battery-powered; you can choose between a replaceable or rechargeable AA or 9-volt lithium battery. Some are also hardwired and need a special wiring to power them; those are typically found only in newer homes and renovated rooms.