Design, Construction, and Use of Minnesota Woman, A Thermally Instrumented Mannequin

Abstract

An adult female thermally instrumented mannequin was designed and constructed for apparel flammability research at the University of Minnesota. Forty-four chromel-alumel thermocouples (0.13 mm diameter) were encased in Pyrex, with measuring junctions exposed, and installed to measure surface temperatures during garment burnings. The thermocouples were arranged primarily in vertical and horizontal alignments on the mannequin torso. The basic mannequin, a molded polyester-fiberglass commercial display model, was coated with a wet mixture of ground asbestos, plaster of Paris, and building cement. The thermal inertia of the coating and that of Pyrex are thought to be close to the thermal inertia of skin and should thus accept heat at a rate approximating that of skin. Surface temperatures were initially measured by potentiometric recorders and then fit to a polynomial function, which provided input surface temperatures for a classical solution of internal skin temperatures. Subsequently, temperatures were recorded by a data acquisition system with an integrating voltmeter and used to calculate temperatures at depths by the finite element method. The degree of injury was predicted from time-temperature relationships at skin layer boundaries according to criteria estab lished by Henriques and modified by Stoll and Greene. Injury extent was expressed as a percentage of body surface area.