The combined environment of high temperature and high humidity is one of the harshest working conditions for hot runner thermocouples, which can greatly shorten service life and induce various electrical and structural faults in a short time.
High ambient temperature raises the overall working base temperature of thermocouples, making them operate near the upper limit of rated temperature for a long time. The internal alloy core wires age faster, thermoelectric performance decays rapidly, and temperature drift becomes more obvious. Meanwhile, high heat softens ordinary insulating materials inside, reducing insulation strength and laying hidden dangers for electric leakage.
Excessive workshop humidity makes a large amount of water vapor penetrate into thermocouple wiring ports, assembly gaps and internal filling layers. Under high-temperature baking, water vapor forms tiny water droplets inside, which erodes welding joints and metal contact points, causing oxidation rust and virtual connection failures. Signal transmission becomes intermittent and unstable.
In addition, the mixture of high temperature, moisture and plastic volatile gas forms corrosive mist, which continuously corrodes the outer protective sleeve and probe surface. The anti-oxidation coating falls off quickly, and the metal body is prone to rust and thinning. The compensation wires outside are also easy to have aging and cracking of insulating layers in such environment.
Moreover, damp and hot environment easily causes condensation inside temperature control terminals, triggering short-circuit protection of the controller and frequent abnormal alarms. To slow down damage, workshops need to install dehumidification and cooling equipment, seal unused wiring interfaces tightly, adopt fully sealed moisture-proof thermocouples, and increase daily inspection and maintenance frequency to ensure stable operation.
