How to Read Carbon Monoxide Detectors

Carbon monoxide is a colorless, odorless gas produced when a fuel source such as natural gas, gasoline, or wood is burned. It is one of the leading causes of accidental deaths in the United States each year. Many people have taken steps to avoid incidents of carbon monoxide poisoning in their homes by installing carbon monoxide detectors. However, without the proper knowledge of how to interpret the readings emitted by the devices, the effectiveness of these early warning systems is greatly reduced.

Installing the Carbon Monoxide Detector

Step 1

Test the unit by inserting the required battery type or by plugging it in. Once the unit has been turned on, push the test button to hear what the warning alarm sounds like. If the alarm is weak or does not sound, check the power supply and try again. Faulty units or dead batteries should be replaced immediately. Some units offer the possibility of using a battery for the backup power supply and an electrical outlet for the main power needs. Using the optional battery is highly recommended.

Step 2

Install the detector in an appropriate location as per the manufacturer's instructions. Placement of the detector will vary according to the unit's power supply (wall socket or battery), the room where the detector is installed and the capabilities of the unit (newer units can be combination smoke/carbon monoxide detectors). Many manufacturers suggest the ceiling as an ideal location because carbon monoxide is often emitted in a heated state, which causes it to rise.

Step 3

Check the digital display for the PPM (parts per million) reading. In general, this reading should be below 35 PPM as this is the acceptable legal limit of exposure to carbon monoxide over an eight-hour period.

Step 4

Change the batteries every six months and refer to the manufacturer's specifications on how often the detector itself should be replaced.

Understanding the Readings and Safety Precautions

Step 5

Make a note of the PPM reading on the digital screen. PPM, or parts per million, is a ratio very similar to a percentage. Percentages are based on a base scale of 100, so 1% is equal to 10,000 PPM.

Step 6

Identify the danger level associated with the PPM reading. U.S. federal regulations define anything over 35 PPM as harmful during prolonged exposures of over eight hours. The alarm should sound if the PPM reading stays between 30 and 40 for more than eight hours. PPM readings of 200 can cause headaches and nausea after a few hours and 400 PPM is considered life threatening after three hours of exposure. The alarm trigger times depend on the PPM level. The alarm will sound once the exposure time at a particular PPM is considered dangerous. For example, 400 PPM should cause the alarm to sound after just a few minutes.

Step 7

Turn off all appliances capable of emitting carbon monoxide, open all windows and leave the home for a few hours if PPM levels consistently reach 200. This action should be taken regardless of whether or not the alarm has sounded. Consistent readings over 35 PPM are cause for further investigation since emissions at this level are indicative of a potential problem.

Step 8

Call 911 immediately if anyone is experiencing carbon monoxide--related symptoms such as headaches, fatigue, nausea, dizziness, or shortness of breath.