In marine environments where high heat output fires are a concern, fixed temperature heat detectors can provide essential property protection. These detectors are designed for areas where ambient conditions might make other detection methods unsuitable. The DFE 135 / DFE 190 fixed temperature heat detectors offer a choice of 135°F or 190°F activation temperatures. UL Listed for ceiling spacing up to 50 feet by 50 feet (2,500 square feet), these detectors feature a self-restoring mechanism and a heat detection element protected by a built-in guard. Electrical contacts are rated at 100 mA and are normally open. The detectors use a bi-metallic disc that deflects when the predetermined temperature is reached, triggering an alarm condition. Multiple base options are available for installation flexibility. Hochiki America Corporation recommends electronic supervision by a UL listed alarm panel and notes that these detectors are not suitable for life safety protection, as smoke detectors should be used in such applications.