1. A method for measuring a flow rate from a metering device, comprising: feeding a flowable particulate material into the metering device; rotating the metering device at a predetermined speed; taking images of the flowable particulate material dispensed from the metering device at a specific rate; measuring a parameter of the flowable particulate material for each image; and comparing the measurement of the parameter of the flowable particulate material for each image with the measurement of the parameter of the flowable material in all images to determine a statistical parameter indicative of flow rate discontinuity.