Review on Horiba Potassium LAQUAtwin Pocket Tester by Cool Martin

These units are defective. I have received the device and completed the calibration procedure but received an error message for a 2000ppm test liquid. I went back and got a replacement. Again I followed the calibration procedure but the unit read 160ppm for a 150ppm test liquid. I calibrated anyway and it worked without errors. However, when I checked the readings with the test liquid, they turned out to be wrong. It would read 500ppm for a 150ppm test at another time and 3000ppm at another time and similarly erratic readings with a 2000ppm test liquid. After receiving two different units that were faulty. I am convinced that these devices are not working properly and am returning them for a refund.