Review on 📏 Improved Measurement Resolution of HM Digital ZT 2 by James Pope

(1) How do I know if this device is accurate? Presumably measuring total dissolved solids? Without a home appliance to compare your readings against, how would you rate its accuracy and therefore its value? (2) This device is designed to be submerged in water and then read dissolved solids, but experience has shown that it will fail if the device is submerged in water. Why can't a device designed for use in water work when wet?