It is perfectly possible! This article has been written for those of you who are very interested in your radon levels, and very curious to know your monitors are working as they should be 😊.
When it comes to comparing radon measurements, it is essential to keep several things in mind, ensuring the comparison is fair and realistic. It is also very important to fully understand how the monitors work themselves.
Are you comparing an Airthings radon detector with another method such as a charcoal test?
Unfortunately they operate in different ways which can often cause confusion when compared against each other. Please see here for our separate article on charcoal testing.
Are you comparing 2 Airthings radon monitors?
If yes, we are talking about any of the following Airthings products, which contain the Airthings radon sensor:
The Corentium Home
The Wave Plus.
The products listed above are all designed for continuous, long-term monitoring of radon. If comparing the monitors, it is helpful to understand how they work and how they should be used:
- We recommend measuring for at least 30 days for reliable averages of your radon exposure.
The radon sensor must calibrate and acclimatize to its environment for several weeks in order to collect enough data points.
- The monitors provide rolling averages, for specific periods of time.
For example, the Corentium Home will show a 1 Day, 7 Day, and Long Term Average (since measuring period began), while the Wave and Wave Plus will show 24hr, 48hr average, 1 week, 1 month, 1 year, etc... These rolling average figures update with each hourly measurement obtained by the monitor.
- There will always be an "acceptable" amount of measurement uncertainty between 2 monitors, even if they right beside each other.
The monitors are provide the average levels of radon in an environment, depending on the amount of radon alpha particles which happen to be present in the particular air sample. Radon is not measured "instantly", like temperature as an example. Radon readings are always measured in terms of averages of air samples taken. This will vary from air sample to air sample, and change with radon fluctuations.
If comparing readings between Airthings monitors, please make sure of the following:
- Did the monitors start their measurements at the same time?
- Are the monitors in the same location and exposed to same conditions? (For example, if they are in the same room, are they right beside other or is one closer to a source of ventilation?)
- Have the monitors been measuring for at least 30 days?
If the answer is No to any of the above, the comparison cannot be made.
If the answer is Yes, our sensor's standard deviation can be applied to the readings.
After 30 days of continuous measuring/acclimatisation:
- σ for 7-Day average is:
+/-10% at ~200 Bq/m3 or ~5.4 pCi/L
- σ after two months:
Long Term average is:
+/-5% at ~200 Bq/m3 or ~5.4 pCi/L
For example, if looking at the 1 week average for 2 monitors after they have acclimatized, it is hypothetically acceptable that one monitor measures 5.94 pCi/L (or 220 Bq/m3) and one measures 4.86 pCi/L (or 180 Bq/m3), as they are within the stated range +/-10%.
If your monitors run for over 2 months, and your levels are around 200 Bq/m3 or 5.4 pCi/L, the monitor should provide a long term average reading +/-5% of this radon level. The longer the monitors run for, the more data samples can be collected, and accuracy/precision is improved meaning you will see that the values of the two monitors eventually tend to converge.