Apera Instruments 201T-S pH Electrode is made for general water solutions' pH measurement in scientific research, environmental monitoring, and quality control. The built-in temperature sensor allows automatic temperature compensation. Apera's special lithium glass membrane ensures low impedance and stable potentials, which helps generate quick and stable pH readings. A unique junction composed of ceramic and fiber filament efficiently improves the problem of junction clogging. A detachable sensor shield is built upon the sensitive glass membrane to protect it from accidental damage. It's the replacement pH electrode for Apera PH400, PH400S, PC400, PH400S, PH400S. Measurement Range: 014 pH, 080?C (32176?F); Housing: Polycarbonate; Junction: Single Ceramic; Reference Electrode: Ag/AgCl; Connector: 8-pin; Size: ø12 160 mm; Cable: 3 Ft; Temperature unit: NTC 30K. Not suitable for testing in low-ion concentration solutions (eg: deionized water or distilled water), strong base solutions (pH>12), highly corrosive liquid, or for continuous testing in high-temperature solutions (>140F). The product is CE and RoHS certified, and is manufactured under an ISO 9001: 2015 certified quality system.