Abstract: An ink jet print head is disclosed which includes a flow path unit with nozzles, a pressure generating unit disposed on the flow path unit and having ink pressure chambers formed behind the respective nozzles, and piezoelectric/electrostrictive elements each disposed on a wall defining a corresponding ink pressure chamber, for deforming the wall to change a pressure of the ink pressure chamber, whereby the ink in the ink pressure chamber is jetted through the corresponding nozzle. The pressure generating unit includes a spacer plate having windows which closed by a closure plate and a connecting plate disposed on the spacer plate, so as to give the respective ink pressure chambers. The connecting plate has communication holes through which the ink pressure chambers communicate with the nozzles. The spacer plate, closure plate and connecting plate are formed from respective ceramic green sheets, which are laminated on each other and fired into an integral ceramic structure as the pressure generating unit.

Abstract: At least one characteristic, such as the mass/density and/or moisture content and/or dielectric constant, of a substance (such as the rod-like tobacco filler of a continuously advancing cigarette rod or a continuously advancing rod-like filler of filter material for tobacco smoke) is ascertained by an evaluating circuit receiving high-frequency signals from a resonator arrangement which receives microwave signals at least at two different frequencies from one or more microwave generators. The substance is caused to advance through a dielectric resonator of the resonator arrangement, and the high-frequency signals are influenced by the substance. For example, the circuit can compare first and second curves of high-frequency signals which respectively are and are not influenced by a selected substance; the curves can have sloping flanks and each of the two frequencies can be allocated to a sloping flank of a curve.