KL-139 TDS Tester Technical Specification: 1.Measuring range:0-1999PPm(mg/L) 2.Resolution:1 PPm(mg/L) 3.Accuracy:+/-2%F.S 4.Operating Temperature:0℃-50℃ 5.Power Supply:2x3V（CR2032 Battery） 6.Environment:Humidity:≤95% 7.Display:4-digital LCD 8.Weight:46g 9.Dimension:150mmx27mmx20mm