The waterproof Hanna Instruments HI 98129 and HI 98130 combination testers offer high accuracy pH, EC / TDS, and temperature measurements in single tester. The Hanna Instruments HI 98129 and HI 98130 combination tester has a large easy-to-read, dual-level LCD, and automatic shut-off. pH and EC / TDS readings are automatically compensated for [...]