Pulverulent flow rate sensor e.g. for paint or enamelling material - has detector sensitive to electric charge on conduit wall produced by friction from flow

摘要

The device has a sensor (11) situated outside the pipe carrying the flow to be determined. The sensor (11) detects the electrical charge resulting from the friction of the product against the pipe's (10) inner wall. The sensor (11) is a conductive component which is placed either near or in contact with the pipe (10). It can partially or totally surround the pipe (10). A circuit gives a signal as a function of the voltage between the axial ends (13,14) of the sensor (11). This signal is used e.g. to send an alarm signal or to stop a control installation. The voltage is measured by a high input impedance amplifier. A smoothing capacitor is situated between the output terminals of the sensor.