Conventional coatings for environmental protection and insulation of thermistors are usually a compromise in terms of performance. Epoxy encapsulation gives good thermal shock properties and corrosion resistance but results in poor flexibility, limited temperature performance, and slow time response. Silicone coatings by contrast perform well at temperatures up to 200°C, are flexible, and allow tight dimensional control for fast time response. They 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 of temperature sensors in harsh environments, such as Euro VI compliant emission reduction systems in diesel engines.