HM COM100 TDS METER W/EC & Temp

Great for testing the percent rejection of your reverse osmosis membrane as well as electrical conductivity  of water & tempurature.
 
Features
Measures electrical conductivity (EC), total dissolved solids (TDS) and temperature.
Three different calibration options (KCl, 442TM, NaCl), each with its own non-linear conversion factor.
Automatic Temperature Compensation (ATC) using three temperature coefficients
Waterproof housing
Measurement Range: 0-9990 S; 0-8560 ppm (auto-ranging).
Digital Calibration (push button)
Auto-off function, data-hold function and low-battery indicator.
Display: large and easy-to-read LCD screen includes simultaneous temperature reading.
Factory Calibrated: The COM-100 meter is calibrated with a 1413 S solution. The meter can be recalibrated with digital calibration using the push buttons, rather than a screwdriver.
Includes a cap, batteries and lanyard.

Specifications

EC Range: 0 - 9990 S
TDS Range: 0-8560 ppm (mg/L)
Temperature Range: 0-80 C; 32-176 F
Resolution: 0-99: 0.1 S/ppm; 100-999: 1 S/ppm; 1000-9990: 10 S/ppm. Temp. resolution is 0.1 C/F
Accuracy: +/- 2%
EC to TDS Conversion Factor: Non-linear conversions for KCl, 442TM or NaCl solutions, set by the user.
Calibration: Digital calibration by push button.
Probe: Detachable platinum electrodes
Housing: Waterproof (submersible)
Power source: 3 x 1.5V button cell batteries (included)
Dimensions: 18.5 x 3.4 x 3.4 cm (7.3 x 1.3 x 1.3 inches)
Weight without case: 90.7g (3.2 oz) 
An excellent water tester.