The Wave Plus, and all of our homeowner product line, are designed for domestic use. They are designed, made and sold with the purpose of providing an accurate and reliable long-term average.
So what's the difference between the Wave monitor and a professional radon detector?
Professional devices are usually equipped so that they can perform a very high number of counts per hour. For example, the Corentium Pro is our professional device, and is fully AARST-NRPP certified for the North American market and beyond.
Our Corentium Pro contains the exact same radon sensor that you'll find in the Wave and Wave Plus, except it contains 4 of these sensors instead of just 1. This allows a lot more data and air samples to be collected in a short amount time, and is therefore certified for professional use.
Now, in line with average consumer usage, this is not necessary as long as the device collects enough data points: since the measurement is fundamentally an average of the amount of the Radon (Rn222) alpha particles present in all the samples of air collected by the sensor, this means that the longer the measurement, the more data points, the more accurate the readings become. Here at Airthings, we usually recommend measuring for as long as possible.
Let's take in a month as an example; wherein you have probably gone through a wide-enough range of temperatures, humidity levels, a few days of rain, etc. In line with this, your device has gathered enough Radon data to start indicating a pattern in which the average calculated/shown will eventually settle on a reference level.