A device for detecting andor measuring air flow in a cooling air flow passageway of an appliance using solid-state flow detectors. In this method, a first aerial image of a first one of the at least two masks is recorded, digitized and stored in a data structure. The cleaner has a resilient support for the blade mount member configured to allow the blade mount member to resiliently rock about the rigid fulcrum member as the scraper blade is impacted during conveyor belt operations.