A Capacitance-Operated Null Detector for Surface Balances
FHC Stewart · Australian Journal of Chemistry · 1961
The Wilhelmy plate technique has been used frequently in work on monomolecular films either in conjunction with an electromagnetic detecting system (cf.Padday 1957) or, more usually, with a torsion balance.I n the latter case the movement of the plate is generally followed optically by means of a small mirror on the balance beam.Another possibility is to utilize the change in capacitance of a small variable condenser having its moving plate attached to the beam (Stewart 1960).The present work describes a simple detector unit based on this principle, which can be used conveniently with a normal laboratory surface trough for routine measurements on monolayers.v PACK