The Application of the
Galvanic Cell Oxygen Analyzer to
Waste Control Programs
K. H. MANCY, Research Fellow
W. C. WESTGARTH,   Research FeUow
and
D. A. OKUN, Professor of Sanitary Engineering
Department of Sanitary Engineering
School of Public Health
University of North Carolina
Chapel Hill, North Carolina
Investigations in the Department of Sanitary Engineering of the University of North Carolina School of Public Health at Chapel Hill have led to the
development of a galvanic cell oxygen analyzer for indicating and monitoring dissolved oxygen in natural waters and wastes. The theory of operation
of this instrument and consideration in its design have been presented elsewhere (1, 2, 3).
Electroactive and surface active impurities in solutions interfere with
the electrode reaction kinetics of exposed metal electrodes. Clark showed
that this interference is eliminated by covering the sensing electrode with a
plastic membrane permeable to oxygen (and other gases in general) but
practically impermeable to ionic species in the test solution (4). Later,
Carritt and Kanwisher devised a temperature-compensated electrode system
composed of a membrane-covered platinum cathode and silver-silver oxide
anode (5).
Electrode systems based on the galvanic cell principle have been used
in Europe by Todt (6) and Husmann and Stracke (7) for the determination of
dissolved oxygen in rivers. In an attempt to minimize the poisoning effect
of impurities in the test solution, mechanically-driven blades were used to
scrape the electrode surface continuously.
The galvanic cell oxygen analyzer consists of a silver-lead galvanic
couple separated from the test sample by a plastic membrane. The generated current is directly proportional to the oxygen content in the sample.
This paper describes its construction, characteristics, and some applications
in the sanitary engineering field.
PRINCIPLE OF THE GALVANIC CELL OXYGEN ANALYZER
Oxygen-sensitive galvanic cells can be designed so that the generated
current is proportional to the oxygen concentration in contact with the cathode. In such an electrode system an outer source of applied voltage is not
needed. The basic design factors of an oxygen-sensitive galvanic cell are:
1) The anode material must consist of a relatively basic metal of reasonable
stability, which has no tendency toward passivation (e. g., zinc, lead, cadmium; 2) The supporting electrolyte must consist of a well-conducting
electrolyte solution which does not dissolve the anode metal at any significant
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