Metal separators of the P-TRON 05 GM type are used for the examination of granulates, ground material or powders in pneumatic conveying lines. Versions for horizontal and vertical installation, as well as for high product temperatures after the dryer, are available. The systems can also be specially approved for potentially explosive areas. The P-TRON 03 FM is available for intermittent suction conveyor lines with short conveyor cycles. A pendulum flap replaces the crimping valves or rotary flaps of the P-TRON 05 GM here.