This weigh hopper with fill/pass valve for dilute-phase pneumatic conveying systems is suspended from three small-scale load cells to deliver higher accuracy than loss-of-weight systems requiring higher-capacity load cells. The system's controller weighs a batch by changing the position of the valve, which diverts conveyed material into the hopper. As the hopper fills, load cells transmit weight gain information to a PLC. Once the batch weight has been reached, the valve redirects material away from the hopper. The controller then actuates a slide gate valve to open, discharging the weighed batch. Rated for the pressure differentials associated with pneumatic conveying, the conical hopper is eccentric with a vertical sidewall to promote complete discharge of weighed materials for batching accuracy. The unit is constructed of stainless steel finished to industrial or sanitary standards to suit food processing applications.