A TDS meter is an inexpensive and convenient digital tool to instantly check your overall water quality. TDS = Total Dissolved Solids, which is any salt, metal or mineral in the water. With the push of a button, the TDS can tell you your overall water purity level, which will be displayed on the screen in ppm (parts per million). The lower the TDS level, the purer the water, with 0 ppm being pure H2O. 

• TDS range: 0 - 990ppm (mg/L), Accuracy: +/- 2%
• TDS stands for Total Dissolved Solids, which are the inorganic salts and organic matter in a liquid. This includes calcium, magnesium, sodium, etc.
• Do not immerse meter in liquid beyond the maximum immersion level of 4 cm.
• Do not store meter in high temperatures or in direct sunlight.
• Battery: 2x LR44