AN ACOUSTICALLY DRIVEN KELVIN PROBE FOR WORK-FUNCTION MEASUREMENTS IN GAS AMBIENT

A vibrating Kelvin probe has been developed for the measurement of work-function difference and outer potential difference measurements in gas ambient conditions. The Kelvin probe consists of a thin conducting diaphragm loosely stretched over the end of a tube. The conducting film is vibrated by an acoustic sound wave coming through the tube. This probe was especially developed for use over liquid as well as solid surfaces and is suited for dealing with problems encountered when making measurements in gas ambient and contaminating environments. The probe head, being aluminized Mylar, is cheap and disposable. Mercury and other liquids can easily destroy or contaminate other probes which are generally delicate and made of precious metal. This probe head also has a more stable work function than many precious metals normally used. Details are presented on construction, theory, operation, and performance. Conducting ionic solutions have been of interest and this probe also works well with them. A working definition of the work function of conducting ionic liquids is presented. © 1995 American Institute of Physics.