The Edwards EST SIGA-HRD is a Signature Series intelligent heat detector that combines fixed temperature and rate-of-rise heat detection in a single addressable device. It continuously monitors surrounding air temperature and analyzes sensor data using on-board microprocessor intelligence to determine alarm conditions.

The SIGA-HRD provides a 135°F (57°C) fixed temperature alarm point and a 15°F (9°C) per minute rate-of-rise function for rapid detection of fast-developing fires. Built-in self-diagnostics and non-volatile memory enhance long-term reliability, while automatic device mapping enables the Signature Loop Controller to supervise device location and prevent misplacement after service.

The detector features electronic addressing, a bicolor (green/red) LED for status indication, and compatibility with a wide range of Signature Series mounting bases, including standard, relay, isolator, and audible sounder bases.