Infrared Marathon FR1 combines advanced electro-optic design with processing electronics for operation in harsh industrial environments. Signal processing electronics support programmable analog and relay outputs, remote parameter configuration, and serial data communications. Device's fiber optic cable is replaceable in the field without need for recalibration. Sensor can be mounted in harsh environment up to 200 °C with electronics mounted remotely. Water-cooled option allows electronics to operate in ambient temperatures up to 150 °C. DSP offers digital communications and Windows software for two-way serial communications, data acquisition, temperature monitoring, diagnostics, and on-site field calibration. Three models cover ranges from 500 to 2500°C. Other features include accuracy or uncertainty to ± 0.3% of value; 10-msec response time; built-in display/user-interface for easy set-up and installation; attenuation measurement; both 1-color and 2-color modes; and NEMA 4 rating. Applications include steel production, metal processing, and glass manufacturing.