摘要 |
An instrument (10) is provided for the measurement of the mass of a fibrous material (11) for the correct control of production processes of fibrous materials such as textiles, wood, tobacco and paper so as to reduce unacceptable products and waste. The instrument (10) has a measuring chamber (13) with a passage (15) through which the material (11) passes. A transmitting aerial (16a) is disposed at one side of the measuring chamber (13) to transmit a measuring electromagnetic signal into the measuring chamber (13), and an operating waveguide plate (17) is disposed between the transmitting aerial (16a) and the passage (15). A ground plate (19) is disposed at the opposite side of the measuring chamber (13) so that an operating electromagnetic wave resonates within the measuring chamber (13), and a receiving aerial (16b) is disposed in the measuring chamber (13) to receive the resonating signal in the measuring chamber (13). The receiving aerial (16b) is operable to detect the frequency of the resonating electromagnetic wave which is used to determine the mass of the material (11). |