The Apera Instruments PC60 Multi-parameter Tester simply tests pH, EC (conductivity), TDS (ppm), salinity (ppt) &temperature in a highly quick & professional manner for all kinds of general water solutions such as hydroponics, horticulture, aquaculture, pools& spas, drinking water, water treatment, cooling towers, environmental monitoring, education, etc. The multi-parameter probe is replaceable and easy to install. 1 to 3 points of Auto Calibration and 0 to 50˚C Auto Temperature Compensation (ATC), 0. 01 pH, 1% F. S, 0. 5˚C accuracy with -2. 00 to 16. 00 pH & 0 to 20. 00 mS/cm measuring range, auto recognition and reminders of stable values improves consistency, saving you the trouble of guessing when to manually hold measurement (auto. hold function available). Easy menu setting, customizing your tester’s functions according to your needs. Smart self-diagnosis, warning of out-of-range measurement and incorrect calibrations. IP67 waterproof and dustproof, floating on water so you don’t have to worry if it falls into water by accident. Up to 1000 hours' continuous operation (without backlit) powered by AAA batteries (with low power warning and auto power off in 8 min if no operation)es with a complete kit of premixed calibration solutions (4. 00 and 7. 00), soaking solutions (3M KCL), calibration bottles, AAA batteries, and a lanyard all in a portable carrying case. The meter is CE certified and comes with a 2-YEAR (6 months for the probe). NOTES: The instrument will NOT perform well for distilled or deionized water's pH measurement ( works well for conductivity). This is because distilled and deionized water do not have enough ions present for the electrode to function properly in pH measurement. To measure distilled or deionized water’s pH, users need to use a specialized pH meter such as Apera SX811-PW. Do NOT store the probe in distilled water or deionized water because they will cause damage to the glass membrane of the pH probe. Only use distilled water for rinsing the probe. Refer instruction manual before use.