What is the minimum distance a measuring device should be from an exterior wall?

The minimum distance a measuring device should be from an exterior wall is typically set at 12 inches. This guideline is crucial for ensuring accurate radon measurements. When a device is placed too close to an exterior wall, it may be influenced by external factors such as drafts, changes in temperature, or varying pressure, which can lead to unreliable readings. By maintaining a distance of at least 12 inches, the device is more likely to capture an accurate representation of the indoor air quality without interference from external conditions. This practice helps ensure that the collected data truly reflects the radon levels present in the living area of the home.