The Thermo Scientific Orion 9103APWP AquaPro double-junction, glass body pH electrode with a semi-micro tip, has a silver/silver chloride (Ag/AgCl) internal reference, a polymer external reference, 0 to 14 pH range, and a waterproof Bayonet Neill-Concelman (BNC) connection with 1 m (39") cable. The semi-micro tip allows for use with small samples and test tubes, while the double-junction reference system separates the sample from contact with silver ions, which prolongs electrode life and allows electrode use with samples containing silver complexing or binding agents such as tris (hydroxymethyl) aminomethane (TRIS or THAM), proteins, and sulfides. Glass body electrodes are useful in highly corrosive environments where epoxy could be corroded, or around proteins and other compounds with high surface tension. This electrode is frequently used for testing water samples.pH range is 0 to 14 (+ or - 0.02 pH), temperature range is 0 to 60 degrees C (32 to 140 degrees F) and body dimensions are 120 mm (4.72") long x 12 mm (0.47") diameter body, with a 1 m (39") cable. Buffer and storage solutions are sold separately. pH electrodes are used for measuring the acidity or alkalinity of a substance. They are often constructed of glass, which senses hydrogen ions, and generates a millivoltage that is picked up by the filling solution and transferred to a wire that connects to the pH meter. Thermo Fisher Scientific manufactures analytical instruments, laboratory equipment, consumables, and software under the Thermo Scientific and Fisher Scientific brands, among others. The company was founded in 2006 and is headquartered in Waltham, MA.