i have no issues with it. Great Radon Detector.

I got this device to study radon concentrations. It converges quickly to the same value as another slower sensor, while continuing to provide near realtime feedback which allows correlation with other external factors such as ventilation. Bluetooth logging is great, but there does not seem to be ANY way to download the actual CSV data. Just a picture of the graph, which becomes less useful as the line gets more compressed horizontally. This drastically limits the usability of the device, as it prevents correlation of the data with other sensors.

Just bought a 'new' 82 year old house with a basement and was concerned with how much radon is actually present. I wasn't really too encouraged that modern practices are still using an absorber test kit that needs to be sent away. Why can't I know immediately? Now you can.

You just plug this in and leave it. It's got a very nice vacuum florescent display on top that very clearly states what the value of radon is AND it records all of the readings on an hourly basis. I can see the fluctuations over time. The seller allowed me to put this device in during the month we closed so now I have 30 days worth of recorded data of an undisturbed and vacant house, 10 days worth of data when we moved in with normal living, and now how much radon is present after I installed a radon mitigator. All that without spending $130+ per 2-3 day radon test.

The logs are saved in the device and you can download it anytime you log into it. The phone app is very straight forward and you log into it via bluetooth. If you need to remotely monitor then you'd have to drum up a solution to capture bluetooth data and pipe it out. That's not my case so this device is perfect for me and my home.

I've got a couple of other air sensors which require access to the interweb and when it drops out it stops recording. Not the RD200. It doesn't care if you look at it or not...it just keeps logging. When you download the log, it saves as a parenthesis deliminated .txt file. You could easily pull it into excel but I haven't tried yet.

Accuracy?: The measurement made by the home inspection averaged 3.5 pCi/l (the acceptable maximum is 4.0 pCi/l). The RD200 shows around 3.3 before we moved in, fluctuated between 1.0-4.5 as I started bricking up a hidden window, to a stead average of 1.1 post mitigator. I haven't compared the measurements saved in the log file with the exact dates of the professional radon test but it appears to be within reason. They're two different test types. What I get is trend data. You can see the three main periods in the attached image (pre-move in, post move-in, post radon mitigator).

There was a sale on this device which was about 20% off after I bought it. Amazon doesn't price match itself. This is probably the most important sensor in the house so I don't necessarily mind.

Buy it!

Works as advertised. Fast and easy to use.

First reading takes an hour (fastest that I have seen). Blue Tooth comms with cell phone - handy. 10% certified accuracy is excellent. Just moving the air around causes it to usually sense more Radon. This detector is high tech at its finest. It requires power from a 120 volt outlet, so it has the power to brightly and continuously show its readings on the top display.