Abstract: 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).

Abstract: Checking system for the scanner station of the nucleonic rod-weight control system of a continuous rod cigarette making machine, in which a stable voltage reference is switched into the circuit in place of the usual ionization chamber balance unit and a measurement is made of the difference between the reference voltage and the scanner station radiation reading while no cigarette rod is present, to determine whether the scanner station is free of debris etc. The system opens the internal shutter of the radiation source to enable the measurement to be made and closes the entrance to the scanner unit to prevent escape of B-particles. The reading circuit includes a sample-and-hold facility which enables the reading to be stored so that it can be subsequently read out by an operator or supplied to a centralized computer control system.