Method and apparatus for determining the mass and moisture content of tobacco

A method of determining the mass and moisture content of tobacco, comprising passing said tobacco between a pair of capacitor plates forming a test capacitor;

• applying an alternating input signal to said test capacitance at a varying frequency changing rapidly in a continuous cyclic manner over a range of frequencies at which a resonance condition occurs with respect to a test signal derived from the capacitor;
• and determining the mass of the tobacco from said resonance frequency, and the moisture content from the magnitude of said test signal at said resonance frequency.

Apparatus for determining the mass and moisture content of tobacco, comprising means for passing said tobacco between a pair of capacitor plates forming a test capacitor;

• signal generating means for applying to said test capacitor an alternating current input signal which varies rapidly in frequency in a continuous cyclic manner over a range of frequencies so as to produce a test signal which varies with the frequency of said input signal and exhibits a resonance frequency;
• and means for producing outputs indicative of the mass and moisture content of said tobacco from the resonance frequency and the magnitude of said test signal at a chosen frequency.

Apparatus for determining the mass and moisture content of tobacco in a cigarette making machine in which a trimming device trims tobacco held on a suction tape to form a filler stream, comprising two capacitor plates, arranged on opposite sides of the filler stream and forming a filler capacitor;

• signal generating means for applying to the filler capacitor and alternating current input signal which varies rapidly in frequency in a continuous cyclic manner over a range of frequencies so as to produce a test signal which varies with the frequency of said input signal and exhibits a resonance frequency;
• and means for producing outputs indicative of the mass and moisture content of the tobacco from the resonance frequency and the magnitude of said test signal at a chosen frequency.

Apparatus for determining the mass and moisture content of tobacco in a cigarette making machine in which a trimming device trims tobacco held on a suction tape to form a filler stream, comprising two capacitor plates, arranged on opposite sides of the filler stream and forming a filler capacitor;

• signal generating means arranged to apply an alternating input signal to the filler capacitor over a range of frequencies such as to produce a test signal which varies with the frequency of said input signal and exhibits a resonance frequency;
• and means for producing outputs indicative of the mass and moisture content of the tobacco from the resonance frequency and the magnitude of said test signal at a chosen frequency, in which the filler stream is enclosed in a wrapper to form a continuous rod further comprising a nucleonic scanner for producing a scanner signal indicative of the tobacco mass in the cigarette rod and means for controlling the position of said trimmer in response both to said scanner signal and to the signal which is derived from said filler capacitor and is indicative of mass.