Computer-compatible system for continuous volumetric measurement of water consumption

Summary An inexpensive drinkometer system is described that is compatible with most data acquisition systems and can be used for continuously monitoring the drinking pattern of laboratory animals. The change in electrical inductance resulting from the descent of a free-floating ferrite unit through a drinking tube, surrounded by a double coil, is converted to a signal proportional to the volume of fluid consumed.The authors gratefully acknowledge the technical assistance of Mr C. Friedinger, Mr V. Studer and Mr J. Wespi. This research was supported by a grant from the Swiss Association of Cigarette Manufacturers to K. Bättig and a predoctoral fellowship from the Swiss Federal Institute of Technology to W. Classen.