You know, I've found good refractometers to be accurate. But they are finicky. You have to know how to use them. For example. We keep our house at 65 degrees. My Brs refractometer sits in the closet. When I take it out of the case and shoot it with an infrared temp gun, it's about 65-66 degrees. These are "Supposed" to be ATC refractometers. But, if your instrument is 65 degrees and your solution is 77 degrees the solution is going to adjust to the temp of the instrument and readings are gonna be way off. "Solutions more dense, reading higher Specific gravity" I have literally warmed the solution up to 70 degrees. And warmed the refractometer up to 70 degrees, took a measurement and calibrated it. Then took a measurement 5 minutes later and it had changed due to it heating up more. Just from holding it from body heat. If you stand under a heat lamp in the bathroom, you can literally watch the specific gravity drop as the instrument heats up and the solution gets less dense[emoji15]. So with my system at 77-78 degrees, I always try and heat the calibration solution and refractometer up to about 77 degrees to get consistent readings. And verify with a infrared temp gun. I think that's where a lot of people get mixed result with refractometers. I use this procedure when comparing the results to the icecap every so often. All in all, refractometers are kind of a pain. That's why I was so excited when this meter came out. It sucks people have had issues with it. Including myself. It seems their customer support is good though.