Many plastics release oily, acidic, or corrosive vapors during melting, which penetrate and damage standard thermocouples over time.
Volatile additives such as lubricants, flame retardants, and blowing agents condense on thermocouple probes and cables, causing insulation degradation.
Acidic vapors from PVC, halogenated materials, and engineered resins corrode thermocouple alloys, leading to drift and failure.
Oily residues form a coating on the probe, slowing thermal response and creating measurement lag.
Sealed mineral-insulated thermocouples with seamless metal sheaths prevent vapor penetration into internal insulation.
High-temperature-resistant fluoropolymer or silicone cable jackets resist chemical erosion and contamination.
Inconel and Hastelloy sheath materials provide superior corrosion resistance against harsh vapors.
Proper mold ventilation reduces vapor accumulation around thermocouples, extending service life.
Without chemical-resistant design, thermocouples degrade rapidly in environments with heavy volatiles.
