Temperature of Pyrex and Porcelain insulators in sunlight

Relative Temperature of Pyrex Glass and Porcelain in Sunlight

By J. T. LITTLETON, JR., Corning, N. Y.

A series of temperature measurements were made on Pyrex glass insulators and porcelain insulators in sunlight. The insulators were placed at the focal point of a large sheet iron reflector, designed to give a considerable amount of spherical aberration. Thermocouple wires were cemented to various points of the insulators and the average steady temperature

obtained by the insulators was noted. The curve between the rise of temperature of the porcelain insulator above atmospheric temperature and the rise of Pyrex glass insulator above this point was plotted. The experiments show that the temperature of the porcelain insulator increases about three and a half times as much as one made of Pyrex glass, exposed under the same conditions.