The Apera 201T-F is a versatile 3-in-1 combination pH electrode designed for precision water analysis. It integrates a pH sensor, a reference electrode, and a temperature sensor into a single body, making it a reliable choice for laboratory and field testing of general water solutions. Key Features & Performance 3-in-1 Integration: Combines pH and temperature measurement in one probe, supporting Automatic Temperature Compensation (ATC) to ensure accurate readings regardless of liquid temperature fluctuations. Robust Construction: Features a durable polycarbonate body that is resistant to impacts, making it more rugged than traditional all-glass electrodes. Lithium Glass Membrane: Utilizes a proprietary high-sensitivity glass membrane that provides a fast response time and high repeatability. Universal Connection: Uses a standard BNC connector for the pH signal and an RCA connector for the temperature sensor, making it compatible with most Apera meters and many other brands. Used, in good condition.