Abstract: A smoke detector includes: a casing; a first light emitting unit; a second light emitting unit; and a light receiving unit. A second scattering angle that is an angle between the reception axis of the light receiving unit and a second extension extending from an intersection of the second emission axis and the reception axis in a direction away from the second light emitting unit is larger than a first scattering angle that is an angle between the reception axis of the light receiving unit and a first extension extending from an intersection of the first emission axis and the reception axis in a direction away from the first light emitting unit.

Abstract: A nozzle includes a slit-shaped discharge port at tip ends of a pair of nozzle walls arranged to face each other at a predetermined interval and a plurality of protrusions protruding toward the facing nozzle walls at tip end sides of the nozzle walls.

Abstract: A smoke detector includes: a casing; a first light emitting unit; a second light emitting unit; and a light receiving unit. A second scattering angle that is an angle between the reception axis of the light receiving unit and a second extension extending from an intersection of the second emission axis and the reception axis in a direction away from the second light emitting unit is larger than a first scattering angle that is an angle between the reception axis of the light receiving unit and a first extension extending from an intersection of the first emission axis and the reception axis in a direction away from the first light emitting unit.

Abstract: A fire monitoring system includes a smoke detector, a first correction unit obtaining a first corrected value by multiplying a difference value between a reference value and a detection value by a first correction coefficient, a first conversion unit converting the first corrected value into a first smoke density, and a fire determination unit determining occurrence of a fire event based on the first smoke density. The first correction coefficient is set on an increase side corresponding to an increase in a rate of change of the reference value to an initial reference value, and an upper limit value is set for the first correction coefficient.

Abstract: A fire monitoring system includes a smoke detector, a first correction unit obtaining a first corrected value by multiplying a difference value between a reference value and a detection value by a first correction coefficient, a first conversion unit converting the first corrected value into a first smoke density, and a fire determination unit determining occurrence of a fire event based on the first smoke density. The first correction coefficient is set on an increase side corresponding to an increase in a rate of change of the reference value to an initial reference value, and an upper limit value is set for the first correction coefficient.

Abstract: A motorcycle provided with a receiving chamber positioned beneath the seat includes a forwardly inclined engine and a generally horizontally disposed transmission to permit expansion of the carrying capacity of the receiving chamber. The receiving chamber rear wall, moreover, is depressed inwardly to create an external recess for extending the clearance space between the chamber and the rear wheel, as well as providing a protrusion interiorly of the chamber capable of positioning a helmet therein.