The SI-111SS, manufactured by Apogee, is a precision infrared radiometer that determines the surface temperature of an object without physical contact. It measures both the subject's surface temperature and the sensor-body temperature. A Campbell Scientific data logger uses these measurements to calculate the correct temperature of the subject. This radiometer features an IP67-rated, marine-grade 316L connector that allows the user to easily swap sensors for recalibration or to replace damaged cables.