Microwave Flow Switch, applying the principle of Doppler Effect, is a flow detection sensor for bulk solid/powder applicable to various application like flow monitoring of pneumatic feeding line, plugged chute detecton, etc... High performance in flow and plugged detection for dry powder. Hardly influenced by adhesion or dust because of high permeability microwave system. Self-diagnosis function automatically detecting decrease of sensitivity. Digital circuit system preventing set value from drifting. Withstanding pressure ability up to -980MPa~+980MPa internal- pressure in pipe.