HM TDS Meter + Case This TDS Meter is ideal for all water purification applications, wastewater regulation, aquaculture, hydroponics, and colloidal silver. A perfect TDS Meter for both consumer and commercial use. SPECIFICATIONS TDS Range: 0 - 9990 ppm (mg/L) Temp. Range: 0 - 80 degrees Celsius Resolution: 1 ppm, 1 degree Celsius (also available in 10 ppm) Accuracy: +/- 2% ATC: Built-in sensor for Automatic Temperature Compensation of 1 to 50 degrees Celsius (33 to 122 degrees Fahrenheit) Power source: 2 x 1.5V button cell batteries (included) Battery life: 1000 hours of usage Dimensions: 15.5 x 3.1 x 2.3cm (6.1 x 1.25 x 1 inches) Weight with case: 76.5g (2.7 oz) Weight without case: 56.7g (2)