It can measure PH / TDS / EC / ORP / temperature. The measurement range is large and wide, and can measure fresh water salinity and sea salt. It is suitable for home, swimming pool, drinking water, and amazing digital water quality monitor for aquarium. Specifications: Range: PH 0.00-14.00pH EC 1-19990us/cm TDS 1-19990ppm ORP 1000mV Temp 0-60 (32F-140F) Resolution: pH 0.01PH EC 1us/cm 0.1ms/cm TDS 1ppm 0.1ppt ORP 1mV Temp 0.1C (0.2F) Accuracy: pH 0.05pH EC TDS 2%F.S ORP 2mV Temp 1.0C Waterproof Level:IP67 TDS Factor:0.5 Automatic shut-off:5 minutes Battery: 31.5V (AG-13)(Not included) Temperature Compensation: 0C~50C Operating Temperature: 0C~60C (32F-140F);RH100%