The GroLine Waterproof EC/TDS Tester is made specifically for hydroponics, providing a simple, inexpensive solution to measure fertiliser concentration in a nutrient solution.

The Hanna Instruments-98318 EC/TDS tester has a graphite sensor that reduces the polarisation effect common with amperometric testers that use two stainless steel pins.

Automatic calibration is achieved easily. Simply submerge the sensor in calibration solution and the meter will automatically detect the calibration standard (5.00 mS/cm in Quick Cal mode or 1.41 mS/cm in standard calibration mode). Temperature is automatically compensated for with the integrated temperature sensor.