Abstract: The invention relates to a method and an ion mobility spectrometer (IMS) for the detection of contaminations by explosives, drugs, wood preservatives or the like. The substance traces collected on a carrier material, e.g. cellulose, are dissolved in a solvent for detection using an IMS and are vaporized together with this solvent from a sample dispenser in the reaction compartment of the IMS. In this way, the sample dispenser can be operated at a considerably lower temperature.

Abstract: In a method for photo-ionization ion mobility spectrometry, a reagent gas is added, in particular an aromatic compound, which has a large ionization cross section in the range of ionizing VUV radiation, but a low probability for the formation of protonated quasi-molecular ions. In this way, the detection of only weakly proton affine substances is also amplified or even made possible at all, and also the detection of electronegative substances in a negative operating mode is improved. Preferred reagent gases are benzene, toluene and xylene. FIG.

Abstract: A tracer head for a copy milling machine which is digitally controlled and causes a model to be scanned by a stylus mechanically mounted in the tracer head. The stylus is deflected both at right angles and tangentially to the surface of the model when the stylus contacts the model to produce scanning signals which are proportional to the deflections at right angles to the model surface and the deflections tangential to the model surface. These signals then are transmitted to a processor which processes, amplifies and subsequently feeds the processed and amplified scanning signals to servomotors of the machine to cut and shape a workpiece in such manner as to produce a copy of the model. The amount of spring pressure exerted on the stylus inside the head by the mechanical spring mounting when the stylus contacts the model is determined by establishing the pressure separately along each of the three mutually orthogonal x, y and z axes.