A Drop Calorimeter with an Electron Beam Heated Furnace

Abstract

The design and operation of a calorimetric system for the measurement of high temperature enthalpy by the method of mixtures, or ``drop method,'' is described. Features of the system are (1) an electron beam heated furnace, with sample temperatures determined by optical pyrometry, (2) a copper block calorimeter with calorimeter temperatures obtained by quartz crystal thermometry, and (3) provision for pneumatic acceleration of the sample from the furnace into the calorimeter to minimize heat losses during the transfer. The system has been used to measure the enthalpy of tungsten in the temperature range 1300–1900 K. Values agree with literature data to ±0.5%.