Abstract: A radiation-activated sprinkler includes a sprinkler body defining a main orifice, the main orifice adapted to couple to a source of pressurized liquid; a deflector coupled to the body; a valve adapted to seat on the main orifice to block the source of pressurized liquid; a linkage mechanism adapted to retain the valve on the main orifice; and one or more fusible links coupled to the linkage mechanism, wherein the one or more fusible links are located substantially externally with respect to the sprinkler body, deflector, and linkage mechanism. The one or more fusible links are adapted to release when exposed to an amount of radiation that exceeds a predetermined threshold, thereby releasing the linkage mechanism from the valve. Other features and related methods are also described.

Abstract: A radiation-activated sprinkler includes a sprinkler body defining a main orifice, the main orifice adapted to couple to a source of pressurized liquid; a deflector coupled to the body; a valve adapted to seat on the main orifice to block the source of pressurized liquid; a linkage mechanism adapted to retain the valve on the main orifice; and one or more fusible links coupled to the linkage mechanism, wherein the one or more fusible links are located substantially externally with respect to the sprinkler body, deflector, and linkage mechanism. The one or more fusible links are adapted to release when exposed to an amount of radiation that exceeds a predetermined threshold, thereby releasing the linkage mechanism from the valve. Other features and related methods are also described.

Abstract: A smoke concentration measurement system includes: a beam extension chamber having a body defining a smoke channel having a longitudinal axis, the smoke channel having a smoke inlet and a smoke outlet at opposite ends of the longitudinal axis, a first reflective surface located on a first lateral side of the longitudinal axis, an entrance window located on the first lateral side of the longitudinal axis, a second reflective surface located on a second lateral side of the longitudinal axis, and an exit window located on the second lateral side of the longitudinal axis. The system also includes a laser light source adapted to emit laser light onto the entrance window, the laser light reflecting back and forth between the first reflective surface and the second reflective surface toward the exit window, and a first light measurement device adapted to receive laser light exiting the exit window. Other features, as well as a method of measuring the concentration of smoke, are also described.

Abstract: An anti-skipping sprinkler includes a frame defining a central longitudinal axis, the frame including a base portion defining an orifice, and first and second arms extending away from the base portion and joining at a lower end of the frame; a deflector located at the lower end of the frame; an orifice plug held over the orifice by a trigger element including a heat sensitive element; and an anti-skipping shield extending circumferentially around the heat sensitive element. The anti-skipping shield has an upper end and a lower end. The anti-skipping shield is open at the upper end and at the lower end to permit airflow to the heat sensitive element around the upper end and the lower end of the anti-skipping shield.

Abstract: An anti-skipping sprinkler includes a frame defining a central longitudinal axis, the frame including a base portion defining an orifice, and first and second arms extending away from the base portion and joining at a lower end of the frame; a deflector located at the lower end of the frame; an orifice plug held over the orifice by a trigger element including a heat sensitive element; and an anti-skipping shield extending circumferentially around the heat sensitive element. The anti-skipping shield has an upper end and a lower end. The anti-skipping shield is open at the upper end and at the lower end to permit airflow to the heat sensitive element around the upper end and the lower end of the anti-skipping shield.