Which of the following is a characteristic of a bypass eductor?

A bypass eductor is a specific type of foam proportioning system used in firefighting to mix foam concentrate with water. The defining characteristic of a bypass eductor is that it efficiently mixes foam concentrate with water before the foam is discharged. This process allows for the proper proportioning of foam and maximizes its effectiveness when used on flammable liquid fires.

The design of the bypass eductor allows water to pass through the unit while drawing in foam concentrate at a specific ratio. This is crucial because effective foam application relies on the right mixture to create a foam that can suppress fire effectively.

In contrast, the other options do not correctly describe the function of a bypass eductor. While some eductors or mixing systems may require manual operation, a bypass eductor can operate automatically or with minimal manual intervention. Moreover, a bypass eductor does require a water source to function, as it needs both water and foam concentrate to create the firefighting foam. Lastly, bypass eductors are not specifically designed for high-viscosity fluids; they are primarily aimed at proportioning foam for a variety of firefighting scenarios rather than handling fluids with high viscosity.