Chemical Behavior of Pt, Al2O3 and Graphite Crucibles and Sensors

Environmental Effects: Chemical Behavior of Crucibles and Sensors Made of Pt, Al2O3 and C

In practice, the service life of sensors (thermocouples) and crucibles is most heavily impacted by interactions with the environment. Diffused impurities, released from the samples, change the thermal tension or may even cause initial cracking of the thermocouple wire and crucible wall. The following tables give some details on the chemical compatibility of Pt, Al2O3 and C thermocouples and crucibles with other sample materials and gas atmospheres. The following lists also serve to illustrate how important regular inspections and calibration measurements are.
These overviews are not exhaustive, but meant rather as a guideline for the user. The temperatures given are primarily literature values. Temperatures under test conditions might shift to lower values. It is always advisable to run preliminary tests in separate furnaces.

Chemical Behavior of Platinum

Chemical Behavior of Alumina

Chemical Behavior of Graphite