We have been trying to use this device for almost a year now. It is fussy and the results are not reproducible. There are a low of uplifting - buy me now reviews online, but based on our experience with this device, those reviews can only be fake. 1. We check the results against 2 other methods. bwb flame photometer gives erratic results with more than +10 mEq for Na. 2. error codes are not documented or user friendly 3. personnel at the maker is difficult to get in touch with and their solutions do not address the issue 4. shipping is horrendous what else is there? Spend your money elsewhere.