What are you trying to measure?
For a home, the aim is to understand longer-term exposure rather than a single moment. Make sure the chosen test answers the question you need answered, particularly if you are working to a property transaction deadline.
Why duration matters
Indoor levels fluctuate. A brief test can be influenced disproportionately by conditions during those days. Longer domestic measurements provide a more useful basis for assessing the annual average. Follow the laboratory’s instructions on duration and placement.
Using a digital monitor
A digital device can show changes and help you observe trends, but interpretation depends on the device, duration, calibration and location. Do not compare an isolated peak directly with a reference level defined as an annual average.
Keep the context with the number
Save the dates, rooms tested and any significant occupancy or building changes. Ask the provider what uncertainty means for your result and whether further measurement is needed before making a decision.
Sources & further reading
UKHSA: measuring radon in homes ↗UKHSA: Action Level and Target Level ↗General guidance for property owners. Check the original source and obtain advice specific to your building.