Hanna Instruments HI 9813-6N Waterproof pH/EC/TDS Temperature Meter Clean and Calibration Check for Growers, 0 to 50 Degree C, 9V Battery: Amazon.com: Industrial & Scientific
Combo pH/EC/TDS/Temperature meter - HI98129 | Hanna Instruments
Amazon.com: Hanna Instruments HI98331 Soil Test Direct Soil EC Tester, 0.0 to 50.0 Degree C, 0.1 Degree C Resolution, +/-1 Degree C : Industrial & Scientific