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Detect and Understand Carbon Monoxide
Detect and Understand Carbon Monoxide

Carbon monoxide readings can be scary at a glance, this article should help you understand what a CO event means

Updated yesterday

⚠️ Warning. If your live reading is currently over 200 ppm, contact emergency services immediately.

The SV25 Is not a life safety device, and does not satisfy the requirements to be used as an emergency carbon monoxide detector.

Do not rely solely on Verkada alerts. These alerts do not provide a sufficient timely warning and the threat to health and safety carbon monoxide (CO) may be compromised.

Common facts about carbon monoxide

What is it?

An odorless, colorless, and toxic gas. Example sources: Automobile exhaust, gas stoves, leaking chimneys, water heaters, and furnaces. Measurement range: 0—1,000 ppm


CO inhibits your blood from carrying oxygen even after getting to fresh air.


CO is primarily a health risk when brief peak exposure is routine or levels in a space continue to rise or do not dissipate.

  • Because it's impossible to see, taste, or smell toxic fumes, CO can be deadly and the presence in a building can be unknown.

  • Detection of singular large spikes do not always indicate a persistent problem or danger.

  • The effects of CO exposure can vary greatly from person to person depending on age, overall health, and the concentration and length of exposure.

Understand an event

Example 1

Scenario: A diesel truck idling near an open window may look like this:

This would equate to about 35 ppm over 5 minutes. If no other events occur, the occupants of that room would have been exposed to:

  • 2.917 ppm/hour

  • 0.365 ppm/8 hours

In this case, the occupants might have been exposed to a peak event, but the total exposure concentration is still very low and of no need for concern. A typical meter will enter an alarm state when exposed to 15–50 ppm over an hour or a sum of 50 ppm over 8 hours.

Example 2

With the same example, assume that this diesel truck will make 20 stops a day. At this same spot, that would be:

  • 7.2925 ppm/hour

  • 58.34 ppm/8 hours

This level indicates actionable concerns, such as making an idle engine policy or closing the window. However, this would not necessarily be an emergency as there is no threat to well-being. If you begin to see events like this regularly and you cannot identify the source, you may want investigate more.

⚠️ Warning. If your fire alarm system enters an alarm state due to the presence of CO, always treat it like an emergency, even if the SV25 does not detect it.

Example 3

This graph is also over the same interval of time; however, the circumstances were life-threatening conditions. Lucky for the occupants, the SV25 was mounted directly next to a certified, life safety carbon monoxide meter. The SV25 is not a certified life-safety carbon monoxide meter.

Just like the first circumstance, the values began with a spike, however ,the level persisted to rise. The building's fire alarm went off and the occupants were evacuated. This represents a life-threatening event. If the occupants had not evacuated, they would have been exposed to 400–500 ppm/hour.

In this case, the SV25 was able to provide insights to the fire department to identify a failed water heater.

⚠️ Warning. If the SV25 sensor's live reading shows unsafe values of carbon monoxide that are increasing or are not dissipating, evacuate the area immediately and contact emergency services.

Need more help? Contact Verkada Support

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