Triple Point Temperature Sensors allow monitoring of three separate temperature points within a vessel using a single probe. Originally designed by Conax for use during the calibration of epitaxial reactors, this technology is now used in a range of industrial process control applications. A tapered sheath ensures the proper location of the measuring junctions.

The original application uses Tungsten/Rhenium thermocouple wires to supply very accurate operation in a 1200° C environment. An inert-gas backfill protects the thermocouple wires from high temperature oxidation.