An all-solid-state reference electrode

Conventional liquid-filled reference electrodes are not suitable for applications where electrochemical sensors must be very robust and capable of withstanding high pressures and temperatures. This paper presents an all-solid-state reference electrode containing essentially an Ag/AgCl-reference element and a solid crystalline KCl melt, but no liquid components. Particularly with regard to the intended application in a brewery, the electrode was successfully tested in combination with a likewise all-solid-state antimony pH indicator electrode, as reference electrode in an all-solid oxygen sensor and in a potentiometric inline sensor using cyclic voltammetry. In spite of various suggestions to solve the problem, no type of all-solid-state reference electrode is available with properties completely comparable to those of conventional ones so far.