Suitable adaptation schemes need to be selected for chemical thermal resistors in different dielectric scenarios. The following are some common adaptation schemes and application examples in dielectric scenarios:
Corrosive medium scenario
Adaptation plan: For strong acid and alkali media, PTFE coated anti-corrosion thermistor or Hastelloy B-type sleeve thermistor can be used to resist the corrosion of hydrochloric acid, hydrofluoric acid, etc. In sulfide environments, it is necessary to choose silicon nitride coated platinum resistors or J-type thermocouples as substitutes to avoid failure caused by sulfur corrosion. Meanwhile, a four layer armor structure can be adopted, consisting of a ceramic outer layer, PTFE isolation layer, argon gas filling, and solid sealing, to ensure the long-term stability of the thermal resistance.
Application example: In the acid-base reaction kettle of chemical enterprises, explosion-proof Pt100 thermistor is usually used, with three wire wiring and a protective sleeve made of Hastelloy C-276 armor, which can effectively resist H ₂ S corrosion and electromagnetic interference, ensuring accurate measurement of the temperature inside the reaction kettle.
High humidity/condensing medium scenario
Adaptation plan: Use IP68 waterproof junction box and silicone sealing ring for thermal resistance, and regularly remove condensed water. Nano hydrophobic coatings can also be applied to the surface of the thermistor, with a contact angle greater than 150 °, to prevent water vapor penetration from affecting measurement accuracy.
Application example: In food cold storage with low temperature and high humidity, anti-corrosion Cu50 thermistor is used, which is coated with PTFE coating on the surface, which can economically and effectively resist condensation water rust corrosion and achieve stable monitoring of cold storage temperature.
Vibration/high pressure medium scenario
Adaptation plan: Armored thermal resistors, such as those with stainless steel sleeves, can be selected, which can withstand 200Hz vibration and 50MPa high voltage, and have built-in serpentine electrodes to disperse stress. For scenarios with higher anti vibration requirements, anti vibration reinforcement models can be chosen, such as the Hequan TC-600 series, which has built-in spring buffering that can reduce the failure rate by 80%.
Application example: In equipment such as oil pipelines and pumps, due to vibration and high pressure, armored thermal resistors are usually installed to measure the temperature of the medium, ensuring the normal operation and temperature control of the equipment.
Scenarios involving flammable and explosive media
Adaptation plan: Explosion proof thermal resistors must be selected, such as those with ExdIICT6 certification, paired with explosion-proof junction boxes and ceramic filters to block dust and limit explosion risks within a sealed box.
Application example: In the gas monitoring system of coal mines, explosion-proof thermal resistors are used to measure the temperature of relevant areas to prevent safety accidents such as gas explosions caused by abnormal temperature.