| 摘要 |
The mass and moisture content of tobacco forming the filler stream in a cigarette making machine are determined by a pair of capacitor plates placed on opposite sides of the filler stream forming a test capacitor (11). The test capacitor is connected in a series resonance circuit comprising an inductor (20) and a variable frequency voltage source (21) generating voltages which increase in frequency in finite steps over a range above 1 MHz. The voltage source is controlled by a processing unit (24) which also receives an indication of the voltage across the test capacitor (11). The mass and moisture content are derived from the resonance frequency of the capacitor voltage and the magnitude of said voltage at a chosen frequency, preferably the resonance frequency. Signals indicative of mass may be used to control a trimming device (7) preferably in combination with signals from a nucleonic scanner (16).
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