A system for dispensing toner particles from a toner hopper to a development system, a sensing system for detecting low toner condition within the toner hopper, the sensing system including a flexible wall assembly mounted within the hopper and in fluid communication with the toner particles within the toner hopper, the flexible wall assembly being adapted to transmit an interior pressure generated by the toner within the toner hopper being indicative of an amount of toner present therein; and a sensor assembly mounted exterior to the toner hopper and in communication with the flexible wall assembly, for sensing the interior pressure. There is provided circuitry responsive to the sensor for generating a feed back signal indicative of a low toner condition within the toner hopper.