Improper storage of spare thermocouple inventory leads to premature aging, terminal rust, sheath oxidation and insulation damp failure before installation, resulting in high defect rate after being put into production. Establishing standardized warehouse storage specifications covering environmental control, classified packaging, placement rules and regular inventory inspection can preserve the original precision and service life of spare thermocouples, avoiding waste of procurement funds caused by stored sensor failure.
Storage environment temperature and humidity control is the basic requirement. The thermocouple spare parts warehouse must maintain constant temperature between 18℃–28℃ and relative humidity 40%–65% RH, equipped with dehumidifiers and ventilation fans to prevent moisture condensation on metal sheaths and plug pins. Spare thermocouples are strictly prohibited from being stored near mold cleaning chemical agents, oil storage areas and high-temperature mold preheating zones; volatile corrosive gas and heat radiation will accelerate sheath oxidation and wire jacket embrittlement. In coastal humid regions, place sealed desiccant bags inside each storage carton to absorb residual moisture in the packaging space. Warehouse lighting should avoid direct sunlight long-term irradiation, as ultraviolet rays degrade fiberglass and PTFE outer protective sleeves and make them brittle.
Classified sealed packaging prevents cross-contamination and oxidation. New thermocouples delivered from suppliers should retain original moisture-proof anti-rust packaging; after unpacking for sampling inspection, repack with independent anti-rust oil paper and sealed plastic bags before returning to inventory. Classify storage by core parameters: separate K, J, N, E-type thermocouples; sort by sheath diameter 0.8mm, 1.0mm, 1.5mm; divide flat-head, probe, button and integrated valve gate types into independent storage boxes, with clear labeling of wire length, sheath material and applicable hot runner brand on each box. Medical-grade and ordinary industrial thermocouples must be stored in separate zones to avoid residual corrosive impurity cross-contamination on medical sensor sheaths. Do not store thermocouples together with steel screws, metal cutting tools and sharp mold accessories to prevent sheath scratch damage during stacking.
Scientific placement rules avoid mechanical deformation and wire breakage. All spare thermocouples are placed horizontally in plastic storage boxes with soft sponge lining at the bottom, prohibiting vertical insertion stacking that squeezes thin armored probes to bend and deform. Long wire thermocouples are coiled into large-diameter loops with radius over 10cm instead of tight small circles, to eliminate permanent stress damage on internal alloy wires caused by sharp bending. Do not stack heavy mold spare parts and metal boxes on top of thermocouple storage cartons; long-term compression will deform seamless armored tubes and crack internal insulation powder. Ultra-thin 0.8mm miniature probe thermocouples are stored in independent small separated sponge slots to prevent mutual extrusion and bending of slender sensing heads.
Regular inventory inspection and pre-use re-inspection eliminate hidden aging faults. Conduct full inventory inspection of spare thermocouples every quarter: wipe off surface rust spots on plug pins with anti-rust cleaning cloth, replace failed desiccant bags in packaging boxes, and pick out products with cracked outer sleeves and discolored oxidized sheaths for scrapping. When taking thermocouples out of inventory for mold assembly, mandatory pre-inspection steps include multimeter open/short circuit test and appearance recheck; for spare sensors stored over three months, add a quick temperature calibration test with a portable heat gun to confirm no drift deviation caused by long-term storage dampness. Thermocouples stored over six months are prohibited from being directly used on high-precision automotive and medical molds; they must pass formal dry block furnace calibration before installation.
Long-term offline storage disposal rules for disassembled used thermocouples. If temporarily removed thermocouples need to be stored for more than one month, completely clean carbon deposits and oil stains on sheath and sensing head surfaces, coat a thin layer of anti-rust oil on metal parts, then wrap with oil paper and seal in moisture-proof boxes separately, instead of leaving them attached to mold plates for storage. Label disassembly date and original mold information on packaging to distinguish new spare sensors and recycled disassembled sensors, avoiding mixed use on high-standard production lines.
Standardized storage specifications maintain the original performance of hot runner thermocouple spare parts, reduce scrap rate of inventory sensors, and ensure stable supply of qualified matching sensors during mold maintenance and trial production.
