Thermistor Coating for Harsh Environment Applications

Amphenol Advanced Sensors' Thermometrics product line will be showing the new Chip Thermistor for Harsh Environments at electronica show. NTC Type CR-1 harsh environmental chip thermistors from Amphenol Thermometrics® are Sn-coated Alloy 52 leads with high performance acid and moisture resistant coating. These NTC chip thermistors are designed for use in harsh environmental conditions in automotive, industrial, and aerospace applications and fully integratable into high volume assembly.

Thermometrics new CR1 coating offers one of the most advanced high performance coatings on the market. Originally developed for the automotive industry and harsh environment applications such as exhaust gas recirculation (EGR) systems, air intake manifold (AIM) sensors and temperature and manifold absolute pressure (TMAP) sensors, the CR1 coating offers some unique properties that can be used in many applications where moisture, high temperatures or chemicals can damage other thermistor coatings.

"Conventional coatings for environmental protection and insulation of thermistors are usually a compromise in terms of performance and susceptible to degradation over time" says Mark DeNovellis Global Product Manager.

"Epoxy encapsulation gives good thermal shock properties and corrosion resistance but poor flexibility, limited temperature performance and slow time response, silicone coatings by contrast perform well up to 200 degrees C, are flexible and allow tight dimensional control for fast time response but are limited in their thermal shock performance and resistance to acids.

The use of CR1 in the current innovation overcomes these limitations and addresses a need for improved protection for temperature sensors in harsh environments, such as Euro 6 compliant emission reduction systems in diesel engines."