Polaroid Stress Analyser

The Polaroid stress analyser allows students to view stresses which exist in clear plastic materials. This simple apparatus consists of two crossed Polaroid filter squares (i.e. axes perpendicular to each other), 65 x 65 mm, on a plastic handle. A gap between the Polaroid squares allows clear plastic shapes (or even a clear ruler) to be placed between them, to view any stresses within the material the stresses show as coloured areas and lines within the plastic. The analyser comes with two cut-out shapes which can be compressed to alter the stress patterns. Additional shapes are also available separately (OP74725).