Apera Instruments, AI3121, LabSen 213 Professional 3-in-1 Glass pH/Temp. Electrode for Regular WaterBacked by proprietary Swiss sensor technology and materials, the Apera Instruments LabSen 213 3-in-1 pH/Temp. Electrode Sensor is a temperature compensated pH Electrode, is ideal for precise regular water solutions and water pH testing in scientific research and quality control. This electrode is compatible with TRIS buffer solutions.LabSen unique blue hemispherical glass membrane- faster response time, better repeatability, and built tough, highly resistant to general impact (totally differentiates from the traditional fragile glass bulb membrane); and can be tested in high temperature samples (up to 225°F).Long-Life Reference System- composed of a glass tube, AgCl and a reference silver wire. The top end of the slim glass tube is stuffed with cotton, which prevents the reaction between AgCl and electrolyte when temperature changes. It improves the stability of reference electrode and prolong the service life of the electrode.The patented pH/Temperature combination structure- The temperature element is placed in an independent cavity under the pH glass membrane. With the built-in heat conducting medium, the temperature sensing speed can be increased by 40%, hence the response time and stability of the pH electrode are greatly improved.LabSen unique blue hemispherical glass membrane- highly resistant to general impact (the traditional glass bulb membrane is a lot more fragile), and can be tested in high temperature samples (up to 225°F).Compatible Apera Instruments' meters: PH700, SX823-B, MP511, PH800, PC800. May NOT work with other brands' meters because the temperature unit might be incompatible.Features:Proprietary pH sensor technology and materials from SwitzerlandPatented pH/Temperature combination structure, increasing the temperature respond time by 40% compared to conventional isolated built-in thermistorUnique LabSen blue hemispherical glass membrane, fast response rate and impact-resistantLong-Life Reference System, improving the stability of reference electrode and prolong the service life of the electrodeCompatible with TRIS buffer solutions.