Water purity tester from Xiaomi.
Distilled water: 0-2 ppm
Office coolers: 60-80 ppm
Brita Filter: 160 -170 ppm
Tap water: 240-260 ppm
ppm (parts per million)- is mg of solids dissolved in 1 liter of water
Measure concentration of Calcium and magnesium ions, Ammonium acetate, sodium etc. Chromium, zinc, lead and copper. Soluble Salts, Ionic Organic, Heavy Metal Ions in water.