This unit's readings correlate well to recent charcoal mail-in style tests I had completed on my basement.
I used this unit to get a 30 day average prior to a radon mitigation system install to judge effectiveness of the system.
So far I've measured an 86% reduction in the readings; more importantly my basement is now below EPA guideline value.

This unit is certainly pricey but it should save money and hassle in the long run versus the mail-in style tests.
I'm hoping it'll function for several years so I can truly feel like I've gotten my moneys worth - time will tell.
Also, it's nice to always know the exact levels (1-day, 7-day and Long Term) readings in my basement.

I bought this dosimeter in November 2015, and it worked fine for almost 20 months. [It was checked against charcoal].
Then it stopped working and showed error #4. After contacting Aithings ([email protected]) I was offered
replacement by the new item for free. The response was fast, and the new dosimeter has been sent by Fedex immediately.
I was really pleasantly surprised by this because the warranty has formally expired. I highly recommend this product without any reservations.

I purchased this unit in 6/2014, and earlier this month (2/2017) noted that the device had been displaying a reading of 0 for the last 24 hours as well as the last 7 days, a low level never seen before, although the dot in the upper right corner was still blinking, indicating proper functioning. I did a reset, and it came back up with an ERR 68 code. I could find no reference to define this error code. The batteries tested at the lower end of normal on a battery tester. I then replaced the batteries and within a few hours, was getting readings consistent with my usual range of readings. Apparently, ERR 68 is supposed to tell you the batteries need to be replaced. I wish the instructions would have a listing of error codes and their definitions. It is somewhat concerning that the upper right hand dot would still suggest "normal" operation when the unit was erroneously recording a level of zero.

The device is easy to use, and simple to understand. Gives measurements in 1 and 7 day averages, and long term averages. I've been moving this around my house each week since I got it and one thing I've noticed is that different parts of the house will consistently read a little bit higher on average than some others. Moving it around, I hope, will give me the best long term average. I don't have anything else to compare the reading to, so I can only assume that the readings are accurate.

This tester has been great the 6 months that I have owned it. I learned the radon level in my basement was a fairly consistent 24.00 pci. Finished basement in Illinois). This is 5 times the acceptable limit. test strips just seemed like a bad idea - I wanted to take a measurement anytime and wanted to loan the device to friends.

After installing the SumpDome cover over the sump pit my level dropped in half the next day around 12.00. Still way to high.

Radon installation code says you shouldn't install the fan over the sump pump. I bought a cheap Chinese jackhammer off of amazon and chipped a nice 3 inch hole next to the sump pump where the lateral pipe was draining into the pit. This allowed me to tap into the lateral that extends completely under the basement. Installed a 3 in PVC pipe and used grey cement caulk to make air tight. Ran pipe out into the garage, installed the radon fan in garage space and ran the PVC pipe into the house attic to vent. When the temp is better I plan to extend through the roof. The pci rate immediately dropped to aroung 2.5 pci. Not a bad reduction and hopefully saves me from lung cancer! I can check the meter anytime I walk into the basement since it is always ON, I just leave it on a desk in the basement.