Backed by proprietary Swiss sensor technology and materials, the LabSen 221 Routine Combination pH Electrode is designed for viscous and low ion concentration samples’ pH testing, and ideal for titration. The electrode is compatible with TRIS buffer solutions. Moveable Sleeve Junction – The LabSen 221 pH electrode is easy to clean, especially suitable for low ion concentration solution and non-aqueous solution. The infiltration rate of the electrolyte is determined by the tightness of the sleeve during installation. Long-Life Reference System – The LabSen 221 pH electrode adopts a long-life reference system, which is 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 the temperature changes. It improves the stability of reference electrode and extends the service life of the electrode. Special Glass Membrane – The LabSen 221 pH electrode adopts a Cylindrical glass membrane, which is 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 176°F).