An electronic device for automatic precision measurement of polarographic drop-times on single drops and for recording complete electrocapillary curves

Abstract

The main principles of a new device for measuring polarographic drop-times is described. The instrument uses the periodic change of the electric impedance of the falling mercury drop to control an oscillator circuit. The equipment can be adapted to a normal d.c. polarograph. When it is connected with an XY-recorder it is possible to register complete electrocapillary curves. The method is illustrated by examples with strongly adsorbed sulphur- and selenium-compounds. On single drops, with the normal drop-time 3–5 sec, the standard deviation is less than 1 msec.