Professional radon monitors: what your tester uses

The radon measurement itself can be similar. Airthings' household detectors and its Corentium Pro both use alpha spectrometry, and Ecosense's RadonEye Pro uses the same kind of pulsed ion chamber, with the same stated sensitivity of 30 counts per hour per pCi/L, as its household RadonEye. The differences are in what surrounds the sensor.

The first is calibration. Airthings says each Corentium Pro is calibrated by the manufacturer, that its calibration certificate is valid for one year, and that most jurisdictions require annual calibration for professional use. Ecosense says the RadonEye Pro requires annual calibration and offers it at its own calibration center. A household monitor has no such cycle: C-NRPP says consumer devices cannot be professionally calibrated and are not approved by C-NRPP for use by radon measurement professionals.

The second is the test itself. A professional device is set up for a defined test, with a delay at the start and a fixed length, and its software records what happened during it. Airthings recommends at least 48 hours with a 4-hour delay for short-term tests, ending in 24-hour increments. Ecosense's RadonEye Pro app asks for at least 46 valid hourly data points after the first 4 hours are discarded, or 44 in Illinois, which a 48-hour test after a 4-hour delay meets. Both makers log more than radon: Airthings records motion events, and Ecosense lists temperature, humidity and tamper sensors.

The third is the report. Airthings' online Pro Dashboard holds a testing company's monitors, staff, certifications and report templates, and a technician can add photos and notes on deviations from protocol before a report is generated. Ecosense says the RadonEye Pro generates ANSI/AARST-compliant or standard reports from its app or web dashboard. A household monitor shows a number; a professional device ends in a document a buyer, seller or lender can read.

Airthings describes the Corentium Pro as a fully AARST-NRPP and NRSB certified product for radon professionals. It counts radon by alpha spectrometry with 4 silicon photodiodes in 4 distinct radon chambers, which Airthings says work in parallel, and states a range of 0 to 2,700 pCi/L. It logs temperature, humidity and barometric pressure as well, stores 5 years of hourly data, and runs on 3 AA alkaline batteries for about 15 months.

It has no screen and no on/off button, only status lights. Tests are started and finished in the Corentium Pro app over Bluetooth, and data sets go to the online Pro Dashboard for reports; Airthings notes there is no live, remote access to the monitor. It must sit horizontally, and has a tripod mount and a slot for a Kensington lock to keep it from being moved during a test. Its full specifications are on the Airthings Corentium Pro page.

The EcoTracker is a different kind of tool. Ecosense describes it as four professional radon detectors combined into a diagnostic system that helps mitigators identify radon hotspots faster. By comparing four locations at once, a mitigator can work out where to put a suction point, check how radon responds as a system is adjusted, and confirm results on site. Ecosense says it suits vacant homes, new construction and pre- and post-mitigation work.

Each monitor has a pulsed ionization chamber and a 0.96-inch OLED display, and offers three modes: 5-minute and 10-minute Sniff Modes for finding hotspots quickly, and a Continuous Radon Monitoring (CRM) mode that stores hourly averages for professional testing. It talks to the EcoTracker app over Bluetooth Low Energy, with no Wi-Fi or cellular connection needed. Ecosense gives a service life of about 5 years.

Ecosense describes the RadonEye Pro as an NRPP/NRSB-certified continuous radon monitor designed specifically for professionals. It uses a pulsed ion chamber with a stated sensitivity of 30 counts per hour per pCi/L, measures every 10 minutes, reports a 60-minute moving average, and states a range of 0.2 to 255 pCi/L. It has an OLED display and a configurable audio alarm, plus temperature, humidity and tamper sensors.

It runs from a 12-volt adapter and has no battery backup; for portable use Ecosense describes a 5-volt battery pack with a step-up cable, lasting about 72 hours on a 20 Ah pack or 105 hours on a 30 Ah pack. Bluetooth handles on-site work and Wi-Fi is optional for remote access, though Ecosense notes that an inspection cannot be started or finished remotely. The device stores up to 10 inspection files. Ecosense includes free NRPP device-specific training.

If a radon test is part of a home sale, you are unlikely to choose the device, but you can ask about it. A tester should be able to answer these without hesitation.

1. 1Step 1 of 4:

   Which device will you use?

   A professional continuous monitor, or a laboratory-analyzed test kit; either can be used by a certified professional.

2. 2Step 2 of 4:

   When was it last calibrated?

   Airthings' certificate is valid for one year, and Ecosense says the RadonEye Pro needs calibration every year.

3. 3Step 3 of 4:

   Which protocol will you follow?

   How long the test runs, how long the delay is, and how the home is kept closed while it runs.

4. 4Step 4 of 4:

   What will the report show?

   The average, the hourly readings, and any movement or interruptions recorded during the test.

To find a certified tester, see radon measurement professionals, and for the wider process, radon and buying a house. The EPA's guidance on a result applies whatever device produced it: fix a home at 4 pCi/L or more, and consider fixing between 2 and 4 pCi/L. If you want to watch radon in your own home over months, a household monitor is the tool for that; every one we cover is on continuous radon monitors.