Radiant energy testing device for fire detectors

A testing device for fire detectors comprises a resistance heating coil disposed outwardly of a clear central area and a collar located to one side of and about the resistance heating element for locating of a fire detector relative to the heating element. The heating element is of a low thermal mass and is quickly activated when connected to a power source thereby radiating heat directly to the housing of the detector. The collar is sized to position the resistance heating coil immediately adjacent the surface of the fire detector and spaced from the heat collection fin to thereby cause a rate of temperature rise within the pressure chamber of the fire detector while maintaining the heat collection fin below its activation point.