Ammonia combination electrode with screw plug head NH1101 – available on request

Description

Ammonia combination electrode with screw plug head NH 1101
Plastic shaft, exchangable membrane module, measuring range 0.1 mg/l?1000 mg/l, 0?+50 ?C, screw plug head, length 120 mm, 12 mm ?
The ammonia combination electrode is a complete potentiometric cell that contains both a silver/silver chloride (Ag/AgCl) reference and a pH measurement element. These elements are housed within a plastic body with a chloride ion-containing electrolyte, and are isolated from the sample by a gas permeable membrane made of polytetrafluoroethylene (PTFE).
Ammonia can exist in two different forms: ammonia as a gas (NH3) and ammonium as the ionised form (NH4+). The concentration of each form in a solution is dependent on the solution?s pH. The pKa is the pH value at which ammonia and ammonium are in equilibrium. The pKa of the ammonia/ammonium relationship is 9.24; thus, at a pH of 9.24 there will be an equal concentration of ammonia and ammonium. As pH decreases, becoming more acidic, the concentration of ammonium increases and ammonia decreases. The opposite occurs as the pH increases. The actual concentration for either species can be determined by knowing the concentration of ammonia and the pH of the sample.