12/28/23- First off, the instructions are very small and difficult to read. But it is simple enough. Plugged it in- didn’t come with a base plug as stated. sRead instructions by taking a snapshot, and enlarging on my phone, and informed me that it would take a minimum of 6 hours for a 1 day reading: No Reading. Still blinking lines both long term and short term. 12/29/23 The next day I still I had no reading and when I hit the button marked “M” , it gave me a code of “CODE2989” in the second field.27 hours later, both readings (short and long term) gave me over 4 readings. Now one would panic, but don’t. This meter takes time to adjust. As every day went on, the reading dropped. It was day 8, and I was at 1.98 long term, and 1.69 short term. Here is the important fact. When moving the unit, AVOID TOUCHING THE “R” button at all costs. That is the reset, which I accidentally did. It reset the system, and now I have to go through the whole process again. As of now, I’m at 3.98 LT and 3.54 ST and dropping…once again. The reason I’m not worried is because I used a quick testing kit and the lab results came back at 1.7. (Picked it up at Menards- $10-15.00). Reading was given to me via email on 1/9/24 (Accustar)(1/11/2024) as I am writing this:Also, I bought another radon meter to have on two floors of the home. That one immediately read within 4 hours of plugging in and I believe it is much more accurate than this one. This radon meter may be more accurate over time, but it takes a very long time to gather its readings. One positive thing about this meter is its portability. That’s why I’m keeping it. It has a rechargeable battery, whereas the other does not. When it’s unplugged, you lose all of its readings, and it have to go through the process again. However it is quick, and in 4 hours, you’re up and running again.I am going to keep both though. I just won’t be counting on one or the other but combining the two together to get an accurate reading of my home. I gave it 3 stars and was thinking of returning this, but as the reading went high and has gone down lower, I can assume that it takes a while to get an accurate analysis.It came in a small box, packaged decently, but missing the plug in DC converter. I have many, so that wasn’t a big deal. One star deduction. The second star removal it’s its long term reading process. Do not expect to get an accurate reading for about 7 days. If you are expecting immediate, and cost is not a factor, then find another product. If cost is a factor, this will do its job, but it will take some time.Final Update- 1/25 has taken approximately 2 weeks for this reader to drop down to expected levels due to the report I reviewed back a few weeks ago. So if you’re expecting an IMMEDIATE accuracy test in 1 day or two, this is most definitely not the product for you. Every day it keeps dropping. See the last picture. This will soon hover around 1.7 is my guess. The other digital reader has already dropped to the expected levels while this one is still attempting to get there…Good Luck!