An air-purge jacket keeps infrared temperature sensor lenses clean and free of debris to reduce maintenance needs and ensure optimal performance for machines using the sensors. The air-purge jacket works with the company’s Micro IRt/c and Micro IRt/c.4 infrared thermometers. The 3” long sensors have 0.375” diameter. The small package allows the sensors to fits into tight areas to provide up-close process temperature monitoring. The air-purge jacket prevents oil, dust, condensation and other debris from obscuring the lens and degrading sensor readings.