Fire Safety Science Digital Archive

Experiments to define the characteristics of torsional vane viscometers when used for measuring the shear stress of foam are described, so that replacement instruments can incorporate improved features. It is shown that shear stress determined by this method is not a fundamental property of the foam but depends upon the instrument dimensions and the method of operation as well as upon the characteristics of the foam. The significant dimensions and operational procedures are identified, and recommendations are made for their adoption.