I'm not questioning the accuracy...I was asking for OPINIONS on most the most acurate and ease of reading. You are correct Tom, unless your comparing to a" known", it's impossible to determine the accuracy of any measuring device.
I can only speak for my results....If I check it within 4 minutes of the prior test, back to back, sometimes I get a different reading...not every time, but sometimes. I have since been told to try to clean the vial (outside) with rubbing acohol prior to using it, to ensure that it is as clean as possible.