A system for controlling the mixing ratio of a multi-component mixture including a first pump connectable to a source of a first component and a second pump connectable to a source of a second component. The first and second pump being associated with at least one linear sensor for generating an output indicative of actual pump speed or shaft displacement of the pump. The system further includes a control circuit operative to utilize the output of the linear sensor of one of the pumps to generate a control signal for controlling the output of the other pump.