Smoke, cause a fire sprinkler. Most fire sprinkler heads appear equipped having a glycerin-filled glass bulb. Because the glycerin heats up due to the warmth from the fire underneath, it expands, shatters the glass bulb, and triggers the sprinkler head. The fire sprinkler switch senses this movement of drinking water https://fire-alarm-systems90012.tokka-blog.com/35709735/a-review-of-fire-alarm-systems