Abstract: An apparatus comprising: a base plate and a cover plate, said plates spaced apart by a pair of transfer blocks being mounted and held between the base plate and the cover plate, mounted between the transfer blocks is one or more fluid flow sensor switches, for measuring the presence of liquid flowing there through. The invention can serve as a substantially automatic means of assuring that there is always fluid available for an applicator, such as a wet blade, as the fluid flow sensors are demand driven. If the fluid runs low, the back pressure on the output side of the fluid line drops, and delta pressure across the fluid sensor increases, causing the fluid sensor to open and fluid to flow. An electrical switch, such as a reed switch, signals the controller that fluid is flowing.