The device that introduces foam concentrate into the water stream to make a foam solution is:

• A. Foam
• B. Foam solution
• C. Foam concentrate
• D. Foam proportioner

Answer: (D)

The main idea is how foam is created by mixing concentrate with water in the proper ratio. The device that does this mixing is the foam proportioner. It meters the foam concentrate into the incoming water stream so the two combine to form the foam solution used for extinguishment.

Foam concentrate is the chemical mixture fed into the system, not the device. Foam solution is the resultant mixture after the concentrate is combined with water. Foam is the finished foam product applied to the fire. So the foam proportioner is the component that makes the foam possible by introducing the concentrate into the water stream.