Abstract: An apparatus for monitoring the blend of fibers being dropped onto a receiver by a plurality of weigh pans responsive to predetermined weights of the fibers being accumulated in the respective weigh pans. An electrical signal is produced when predetermined weights of fibers are loaded into the weigh pans. Each of the weigh pans is equipped with a monitoring circuit which includes load cells operably connected to respective weigh pans which generate an analog signal indicating the weight of the fibers accumulated in the weigh pan. An analog to digital converter converts the analog signal and responsive to being triggered is fed into a latch circuit that is triggered by the electrical signal produced when all of the hoppers are full. A digital to analog converter is connected to the latch circuit and converts the digital signal back to an analog signal that is recorded on a chart recorder.