Abstract: The objective of the invention is a method for detection of alien matter contents in gas, in which method the gas and the substances contained in it are ionized in an ionization room (1). By the present methods impurities in gases cannot be determined fast and in small concentrations. In the method of the invention the ions contained in the gas are separated in a separation section (2) into positive and negative ions, of which at least the ions of either sign are led into a narrow analyzer channel (4). There, due to the capillary force, they are forced to move in the middle section of the channel, from where they are deflected by electric fields of different strength caused by different voltages (U1-U10) into an electrode located at the edge of the channel, where they cause ion current (I1-I10).

Abstract: The application of the electron beam technique in the polymerization of surfaces and purification of flue gases, for instance, often has a high demand of energy. The performance of prior art emitters, often considerably less than 50%, is thereby a major drawback. In the present method, low-energy shaping acceleration is applied first and thereafter the electrons are passed through windows very ideally and homogeneously by the proper acceleration. By means of the method, several successive and/or parallel windows can be provided in the device, the electron power being distributed evenly between said windows.

Abstract: A method for detection of alien matter content in gas, in which the gas and the materials contained in it are ionized in an ionization room (1). The present methods are inaccurate and unreliable. The invention is based on a method, in which the ionized gas is led through chambers (2) containing different electric fields, out of which at least from one of the chambers the field current is measured, from which a signal is obtained, which describes the existence of alien matters in the gas. More parameters are obtained for detection of different materials by measuring favorably the currents passed through several electric field chambers as well as possibly by branching off from the ionization source the flow to different analysis lines of the electric field chambers.

Abstract: The object of the invention is a method for measuring humidity in material to be produced in the form of a web, particularly paper and carton material. According to the method, a chopper in part cuts infrared light brought on the other side of the web through an opal glass window from an infrared source. The radiation is measured in an analysis part placed adjacent a second opal glass window. Humidity in the web is measured by measurement of the measuring and reference wavelengths; intensities with a measuring analyzer and a reference analyzer and simultaneously adjusting the viewing angles of the analyzers in such a manner, that when the position of the material web between the opal windows is changed, the same value for the humidity is obtained. The wavelengths between the measuring and reference channels have been chosen so that they are as near as possible to each other.

Abstract: An arrangement for measuring the thickness of a continuous material web. The thickness of the material web is measured by pressing from opposite sides of the web, and on the same spot, wheels which can rotate against the web. One wheel is equipped with a conductive surface, and the other wheel has a detecting element which measures the distance from the conductive surface.

Abstract: A method and a device for operating and focusing a tomographic x-ray unit using an electron beam and embodying at least one electron gun (1), an anode (2) at which the gun is aimed as well as the x-ray detectors (5) needed to produce a tomographic photograph. In order to construct a device with a sufficiently short exposure time and capable of taking tomographic photographs of fast-moving objects, it is particularly characteristic of this invention that an electron beam (8) emitted by an electron gun (1) is roughly deflected at a hole (4) in the focusing plane (3) which, by means of focusing field lines, draws the electrons into the hole, focuses and accelerates the electron beam which strikes the surface of the anode (2), generating an x-ray source, and that the focusing hole (4) is moved in regard to the anode (2) to generate a series of x-ray sources needed to produce a "layerwise" tomographic photograph of the object under examination.

Abstract: The present invention concerns the measuring of a silicon coating on paper or cardboard moving in the form of a continuous web and which may as fillers contain substances containing silicon such as kaolin, or aluminum silicate. By x-ray radiation from a primary radiation source (3) and passing through the web is excited the characteristic x-ray radiation of an element, in a secondary radiation source (7) on the silicon coating side of the paper web (1), having a higher ordinal number than silicon (Si). The exciting radiation is sent obliquely against the surface of the paper or cardboard, whereby the irradiation of the surface is accentuated and the characteristic x-ray radiation of the silicon in the silicon coating can be excited. The exciting radiation also partly excites the silicon in the filler, but in this case it will be accompanied by the characteristic x-ray radiation of the metal associated with the silicate, such as aluminum in the instance of kaolin.

Abstract: The present invention concerns a procedure and a means for observing streaks in the machine direction in paper or in its coating, on a web (1) in continuous motion, a measuring box (2) being moved reciprocatingly across the paper web, from a light source (A) therewithin light being conducted against the paper web (1) in the form of separate light beams (5) spaced uniformly in the direction across the web, whereafter the intensities of the transmission beams from the paper or of the reflected beams from the coating are measured each separately by means of a detector (7) placed in the path of each light beam (5), the deviation of intensity found by the detector being automatically recorded in time and in space, whereafter the deviations of intensity coming later in succession from other detectors (7) are superimposed in time, whereby when similar intensity deviations come from the majority of the different detectors, the deviation must have been caused by a streak in the machine direction across which the equiv

Abstract: The invention concerns a device for creating an electron curtain (5). The device consists of a cylindrical chamber (1) in which has been accommodated an elongated, electron-emitting filament (2) and a shell (3) encircling the filament so that the filament is located in an elongated depression (6) formed by the shell. Furthermore, the device comprises members (7) for accelerating the electrons and a window (4) in the wall of the chamber (1), through which the electron curtain can be directed to the outside of the device.

Abstract: The invention concerns a procedure and a means for creating an electron curtain (5) intended to be used in irradiating a surface (8) and adjustable as to its intensity distribution. The electron curtain is elicited by producing with an elongated filament (2) placed in a chamber (1), free electrons in a space (6) surrounding the filament, by accelerating the electrons by means of an electrode structure (3) confining the space and by directing the electron curtain formed by the accelerated electrons out from the chamber through a window (4) permeable to electrons in its wall.

Abstract: A procedure for measuring unit area weights (base weights) in materials combinations comprising a base material, thereupon a precoating, and upon which latter there is a surface coating or coatings. The materials combination is irradiated with x-rays which excite the characteristic x-ray radiation of a substance in the precoat, the intensity of which is measured above and below the coated base material, in addition to which the absorption in the materials combination of the primary radiation from the radiation source is measured, whereby from the mutually independent results of measurement obtained the unit area weights of the different courses are calculated.