I spoke with a friend with chemistry schooling and experience and he has worked with similar sensors to what this device will use. He says the accuracy can be +/- 0.1% or better if calibrated properly. This is done through fluorescing optical system which is supposed to be very accurate. My understanding is that once the device is calibrated, it doesn't need to be re-calibrated, just new media.
If true, and Mindstream parameters measure with similar accuracy, than this device (added with a controller that can dose the relevant parameters that are being measured in real time) will be a game changer and must have for so many who enjoy automation. There are just so many possibilities that can come from this. Very exciting! I hope they deliver