Heat history measuring method, heat history measuring tool, and heat history measuring device

摘要

A heat history measurement method that can be used in a heat treatment furnace of a transfer type or a closed type without requiring wiring or the like, and can easily and accurately measure a heating temperature and a heating time in a wide temperature range of about 300 to 1000 ° C., A thermal history measuring tool and a thermal history measuring device are provided. By utilizing the phenomenon that the transmittance in the visible to near-infrared region of the tin oxide film doped with impurities changes irreversibly depending on the thermal history received, the heating temperature and heating time can be estimated. .