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Inner reference electrodes and filling solutions conferring linear temperature characteristics on glass pH electrodes
Author(s) -
Midgley Derek
Publication year - 1994
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.1140060808
Subject(s) - electrode , reference electrode , linearity , compensation (psychology) , glass electrode , materials science , analytical chemistry (journal) , hysteresis , chemistry , electrochemistry , chromatography , electrical engineering , psychology , physics , psychoanalysis , engineering , quantum mechanics
Glass electrodes with linear temperature characteristics are described. By use of a Ag‐AgBr inner reference element and an inner reference solution containing a zwitterionic buffer (MOPS), an electrode is obtained that almost has the ideal characteristics of isopotential pH (pH iso = 7) and zeropoint pH (pH 0 = 7) necessary for use with the temperature compensation circuits on most pH meters. A conventional Ag‐AgCl (3 M KCl) external reference electrode is used. Excellent linearity of changes in standard potential has been observed in the range tested (5 to 65°C), and the slope factor, thermal hysteresis, and speed of response to temperature change are as good as for commercially available electrodes. The application of electrodes with these characteristics should improve the accuracy of temperature compensation in industrial and environmental measurements. Other inner‐reference electrodes and buffers are considered.