BRAKE HORSEPOWER B037
This is a measurement of the actual horsepower going into the pump. You cannot use the horsepower of the driver to get this number because the driver is not 100% efficient.
Brake horsepower is normally measured on a “pony brake”; an instrument that squeezes on the rotating shaft. The pony brake operation is similar to the brake shoes on an automobile, that slows down, or stop the vehicle.