A radon dosimeter is a detector left in place to measure the radon concentration in the air. In Canada, SE Ranking attributes about 480 monthly searches to "dosimètre radon," and the site is not on the first page for this term. The 91-day long-term test addresses this search.

Two durations, two uses

The short-term detector stays in place for 4 days. It serves as an initial screening, for example before a transaction. Total cost: $74.72 taxes included (detector $39.99 + return and lab $25 + taxes).

The long-term detector stays in place for 91 days. Same total: $74.72 taxes included (detector $39.99 + return and lab $25 + taxes). It is left while the house is normally occupied: heating, windows, showers, doors. The result better describes exposure over the season than a few days’ reading.

A 2-hour test does not replace either. Concentration varies with weather, heating, and window opening.

Where to place the dosimeter

Place it on the lowest floor you occupy, in a living area, at breathing height, away from a window, heating vent, and exterior wall. Do not put it in the kitchen, bathroom, or closet.

For the 4-day test, keep windows closed as much as possible. For the 91-day test, live normally. This is the purpose of the long measurement.

How to read the result

Health Canada sets an intervention threshold at 200 Bq/m³. The World Health Organization uses 100 Bq/m³ as a reference level. Below 200 Bq/m³, the long-term test result serves as a guideline. Above that, a mitigation installation is planned with a quote. The standard installation costs $2,799.99 + taxes, price confirmed before work.

The number alone does not indicate where to run the pipe. It indicates if the house exceeds the threshold. For next steps, call 418-681-7964 or request a quote on the mitigation page.