I have professional background using many types of test equipment & detectors. After giving this a long test run since Radon is a daily fluctuating occurrence. This makes it very hard to assess this detector's accuracy. It has different settings & functions for quick response, long-term, etc. It also has an easy-to-read display. This tester sits on a little stand as a clock would. I've seen it jump readings from very low to higher in a very short span of time. We have had our home tested by professionals & results were very low radon. I also have mixed feelings on Radon's effects since it has been so commercialized for $$$$s I'm just not sure if it is even the health threat it's made out to be since it has been around for most likely forever.