A pyrometric differential thermal analyser for high temperatures

An apparatus for differential thermal analysis to a temperature of 3400°C is described. The specimen is heated inductively with a frequency of 1 MHz either without crucible at its upper end only or in a crucible which is one of the components of the system investigated. The differential principle is applied by comparing the radiation emitted from the sample with the power fed to the sample, which is registered by a bulb coupled to the high frequency circuit. The emission of the sample and bulb are measured by two photodiodes. The different behaviour of sample and bulb is compensated electronically. Investigations in metal ceramic eutectics are given as an example.