HM Digital TDS-3 Handheld Meter With Carrying Case Ideal for all water purification applications, wastewater regulation, aquaculture, hydroponics, and colloidal silver. Perfect for both consumer or commercial use. Carry one in your pocket or toolbox at all times! Features Ideal for commercial use. Includes a carrying case with belt clip. Highly efficient and accurate due to its advanced microprocessor technology. Hold Function: saves measurements for convenient reading and recording. Auto-off function: the meter shuts off automatically after 10 minutes of non-use to conserve batteries. Measurement Range: 0-9990 ppm. From 0-999 ppm, the resolution is in increments of 1ppm. From 1000 to 9990 ppm, the resolution is in increments of 10ppm, indicated by a blinking 'x10' image. Built-in digital thermometer Display: large and easy-to-read LCD screen. Factory Calibrated:ﾠour meters are calibrated with a 342 ppm NaCl solution. Meters can be recalibrated with a mini-screwdriver. Also available in "x10" mode: reads in increments only of 10 ppm (0-9990 ppm). ﾠ Specifications TDS Range:ﾠ0 - 9990 ppm (mg/L) Temp. Range:ﾠ0 - 80 degrees Celsius Resolution:ﾠ1 ppm, 1 degree Celsius (also available in 10 ppm) Accuracy:ﾠ+/- 2% Conversion Factor:ﾠNaCl (avg. 0.5) ATC:ﾠBuilt-in sensor for Automatic Temperature Compensation of 1 to 50 degrees Celsius (33 to 122 degrees Fahrenheit) Power source:ﾠ2 x 1.5V button cell batteries (included) (357A) Battery life:ﾠ1000 hours of usage Dimensions:ﾠ15.5 x 3.1 x 2.3cm (6.1 x 1.25 x 1 inches) Weight with case:ﾠ76.5g (2.7 oz) Weight without case:ﾠ56.7g (2 oz)