A chloridometer is a measuring instrument used to determine the concentration of chloride ions (Cl) in a solution. It uses a process known as coulometric titration or amperostatic coulometry, the accepted electrochemistry reference method to determine the concentration of chloride in biological fluids, including blood serum, blood plasma, urine, sweat, and cerebrospinal fluid. The coulometry process generates silver ions, which react with the chloride to form silver chloride (AgCl).
The first chloridometer was designed by a team led by Ernest Cotlove in 1958.
Other methods to determine chloride concentration include photometric titration and isotope dilution mass spectrometry.