Abstract: The invention refers to a method of detecting workpieces in an electrostatic coating system, comprising at least one electrostatic coating device, which applies a high voltage to a high voltage electrode, in which the high voltage electrode generates a spray current including electrostatic charges for charging particles of a coating medium to be sprayed, an electrically conductive workpiece to be coated is moved past the coating device, the spray current of the high voltage electrode is determined and it is detected in accordance with the magnitude of the spray current whether the workpiece is in front of the coating device.

Abstract: A powder coating system and method comprises a plurality of coating units arranged substantially vertically one on top of the other for simultaneous powder discharge to a workpiece which is moved in horizontal direction past the coating units, and further comprises a monitoring means for detecting a powder stream which flows through the respective coating units.

Abstract: The invention relates to a control system of a coating apparatus for a coating medium, such as powder or wet lacquer, comprising at least one coating device, in which a quantity measuring means for determining the amount of coating medium supplied to the coating device, a quantity control means for setting the quantity of the coating medium to be discharged by the coating device, and a digital control device for controlling the operation of the coating device are associated to the or any coating device, wherein the control device, the quantity measuring means and the quantity control means are connected to one another by a bus structure.

Abstract: The invention provides a method for determining the composition of fluidizable solid matter particles, such as powder particles, in which the solid matter particles are fed through a measuring resonator device comprising a high frequency resonator under defined feeding conditions, and a change of the resonant frequency and/or the amplitude of the high frequency resonator is detected in the measuring resonator means, said change being caused by the fed solid matter particles.

Abstract: The invention refers to a method of controlling a coating device, which discharges a coating medium such as a powder or wet lacquer to a workpiece, in which in accordance with the shape of the workpiece the shape of the cloud of the coating medium discharged is automatically adjusted by changing at least one of the velocity, and the quantity, and the mass flow of the coating medium discharged or shaping air. The invention further refers to a coating installation capable of operating by this method.

Abstract: A device and method of measuring and controlling the flow rate of a fluid determine analog process variables which are dependent on a volumetric flow of the fluid, and the values thus obtained are converted into digital values, the latter being corrected by an offset value which is dependent on a change of the operating parameters of analog components of the measuring system occurring in the course of operation of the system. To obtain the offset value, an analog process variable is determined during interruptions in operation, when the volumetric flow is zero, and converted into a digital value. This digital value is memorized and used as the offset value when operations are resumed. The digital corrected measured values are supplied to a digital signal processor and the flow rate control is carried out digitally. Preferably, at least one parameter memory is provided for the digital control.

Abstract: A method of photothermally examining workpiece surfaces, wherein an electromagnetic exciting beam is directed from a measuring unit to a point to be measured on the workpiece surface so as to heat the workpiece surface at that point and, furthermore, the heat radiation emitted from the point to be measured is detected and analyzed, is characterized in that a plurality of selected points to be measured on the workpiece surface are irradiated by at least a partial beam of the exciting beam, and the heat rays issuing from the points to be measured are sensed and subjected to joint analysis.

Abstract: Apparatus and method of determining the surface condition of a workpiece, operate by measuring a roughness profile of the surface across a certain measuring distance, splitting up the roughness profile into wave frequencies and amplitudes associated with them, dividing the wave frequencies into wave frequency ranges, and determining the surface condition of the workpiece based on the amplitudes in the respective wave frequency ranges. The roughness profile may be understood as the superpositioning of harmonic oscillations having certain wavelengths and amplitudes. By subjecting them to a Fourier analysis, these harmonic oscillations are split up into their wave frequencies and associated amplitudes. Then wave frequency ranges are combined to form bands such that a high intensity in one of the bands each corresponds to a certain physical appearance of the surface. The invention thus provides an objective, calculable measure of the surface condition of a workpiece.

Abstract: The instant invention relates to an apparatus for measuring a powder mass flow in a powder/gas mixture during the conveyance thereof through a feed pipe, the apparatus comprising a velocity measuring device for the powder/gas mixture, a mass measuring device for the powder mass per volume unit, and a calculating device to calculate the powder mass flow based on the velocity measured, the powder mass per volume unit measured, and the dimensions of the feed pipe. The mass measuring device comprises a microwave resonator and means for sensing the resonant frequency and/or the microwave amplitude of the microwave resonator. The microwave resonator is embodied by a coil which is applied on the outside of the feed pipe.

Abstract: A nondestructive workpiece testing method and apparatus are provided, wherein an electromagnetic, intensity modulated excitation beam is directed at a point of examination on a workpiece surface, and wherein thermal radiation emitted by the point of examination is detected and evaluated, the excitation beam being guided periodically in different directions in each one of which it is directed at a different point of examination on a workpiece surface. Moreover, an apparatus is provided for nondestructive workpiece testing, comprising an excitation source for the emission of an electromagnetic excitation beam, an optical means to modulate the intensity of the excitation beam and to direct the excitation beam at a point of examination on a workpiece surface, further comprising a detector means to detect the thermal radiation emitted by the point of examination.

Abstract: A method for photothermally testing workpieces, which includes the steps of directing an electromagnetic excitation beam to a desired measuring point on the workpiece surface, detecting and evaluating the heat in the form of thermal radiation which is generated by the excitation beam at the measuring point with the aid of a measuring head; directing two visible locating beams to the workpiece surface, the two locating beams intersecting at a point of intersection; and correcting the relative position between the workpiece and the measuring head so that the point of intersection and the desired measuring point coincide on the workpiece surface.

Abstract: A cleaning device for a powder coating compartment that comprises a tube system that can be moved back and forth under motor drive through the compartment with a conveyor that passes through a longitudinal slot in the compartment roof and that is equipped with nozzles through which compressed air can be blown against the compartment walls, The tube system comprises two tube branches that are respectively arranged at the contour of the compartment roof and the compartment side walls symmetrically relative to a longitudinal center plane; and in that the compartment floor not swept by the tube system is covered by a discharge belt for eliminating excess powder. The belt is cleaned by a belt cleaning mechanism.

Abstract: A process of powder coating of workpieces in which initially a workpiece is coated with color powder such that the powder adheres to the workpiece and subsequently the powder is baked in an oven, in which subsequent to coating and prior to baking the powder adhering to the workpiece is irradiated with electromagnetic radiation within a particular, defined surface portion so that the powder within the defined surface portion will gelate and stick to the workpiece, and in which the color powder adhering to the workpiece outside of said defined surface portion is removed subsequent to irradiation.

Abstract: A trace gas detector including in a closed gas loop, two baffle cells with an intermediate trace gas filter, each baffle cell consists of an ionization source, a labyrinth-like recombination zone and a collector electrode. A differential circuit derives a differential signal from output signals of the two baffle cells, the differential signal depending only on the trace gas concentration. Temperature changes and supply voltage changes are compensated by means of the differential circuit.

Abstract: A disc valve having a valve housing with a conduit therethrough and a seal ring mounted to the housing. A disc can be pivoted about a pivot axis that is offset from the main valve axis and perpendicular thereto between an open position and a closed position in which a seating surface of the disc contacts a sealing surface of the seal ring in a sealing plane that is perpendicular to the valve axis. The seating surface of the disc is a conically shaped surface that is concentric with the valve axis when the disc is in the closed position. At least a portion of the sealing surface of the seal ring at the intersection between the sealing surface and the sealing plane has the same conical shape. The seal ring can be deflected by moving the disc beyond the closed position to thereby increase the sealing pressure between them.

Abstract: A disc valve for placement in a cylindrical housing forming part of a conduit which has a pivotally mounted disc and a valve seat that is angularly inclined relative to a plane perpendicular to an axis through the housing. The disc has a peripheral seal defined by a plurality of seal rings disposed within a peripherally open groove in the disc. The root diameter of the groove is smaller than the inner diameter of the seal rings so that the latter can float relative to the former. A lock ring securely retains the seal rings in place after the seal rings have been centered relative to the valve seat by first closing the disc and thereafter tightening the lock ring. A space between the seal rings includes generally radially oriented openings in fluid communication with a source of a pressurized medium on the exterior of the valve for applying the medium to the space between the seal rings and to thereby clean the valve seat when closing the disc.

Abstract: A disc valve for placement in a cylindrical housing forming part of a conduit which has a pivotally mounted disc and a valve seat that is angularly inclined relative to a plane perpendicular to an axis through the housing. The disc has a peripheral seal defined by a plurality of seal rings disposed within a peripherally open groove in the disc. The root diameter of the groove is smaller than the inner diameter of the seal rings so that the latter can float relative to the former. A lock ring securely retains the seal rings in place after the seal rings have been centered relative to the valve seat by first closing the disc and thereafter tightening the lock ring. A space between the seal rings includes generally radially oriented openings in fluid communication with a source of a pressurized medium on the exterior of the valve for applying the medium to the space between the seal rings and to thereby clean the valve seat when closing the disc.