We get a lot of questions about the 'coverage areas' or 'area of coverage' for our IAQ monitors. It is important to note that, in one sense, there is no such thing.
Indoor Air Quality Monitors measure the quality of air that the sensors come in contact with. They are effective because the air that they sample is roughly representative of the air nearby. This is because gasses naturally distribute themselves throughout a space, although some are denser at different heights. Air also tends to circulate in response to ventilation, heat, or movement, so your IAQ monitor is usually measuring a different sample at any given time.
The problem is that air can't easily bypass physical barriers, so your monitor will better represent the air six yards in front of it compared to air six inches behind it, on the other side of a wall. Other factors like window drafts can also affect accuracy.
For these reasons, instead of 'coverage', we prefer to talk about monitor density and placement guidelines based on established standards, such as the WELL Performance Rating and RESET Air.
Monitor density refers to the number of monitors in a given space: the more IAQ monitors you have strategically placed throughout a space, the better your overall IAQ picture is, based on their combined readings.
Placement guidelines refer to the recommended places to position your monitors in order to have the best, and most reliable, representation of your air quality possible.
Because of this, many verified building standards, such as WELL and RESET, have issued their own guidelines on the number of monitors you should have in each space (aka. the monitor density for each space/floor/building) and their general placement/deployment in order to achieve their standard.
For more information on these standards, please refer to our resource article on Coverage Areas, Monitor Density, and Placement Guidelines.