Abstract: A welding machine produces a spot-welded joint between two components to be welded together by at least one electrode being in contact with one of the components, by passing a welding current through the components during a welding period, and measuring a thermo-electrical voltage between the electrode and the components outside the welding period. A method for monitoring the welding machine on the basis of the thermo-electrical voltage includes determining a monitoring variable from the thermo-electrical voltage and comparing the monitoring variable with a reference variable of the welding machine. The method can be used for regulating a welding machine, especially for producing a plurality of spot-welded joints. A device for carrying out the method includes at least one measuring instrument, in particular a voltage meter, disposed between the components to be welded together and the electrode. An evaluation and regulating device is connected downstream of said measuring instrument.

Abstract: A process for determining a temperature at a spot weld formed between two parts being made of at least one first metal by at least one electrode being made of a second metal and being in contact with one of the parts, includes determining a first measurement value for a thermoelectric voltage between the electrode and the parts prior to forming the spot weld. A second measurement value is determined for a thermoelectric voltage between the electrode and the parts after forming the spot weld. The temperature is determined by taking both measurement values into account. A device for determining a temperature at the spot weld includes at least one volt meter for ascertaining a thermoelectric voltage between the electrode and the parts, corresponding to a temperature. A control unit records at least one first measurement value for the thermoelectric voltage prior to formation of a spot weld and at least one second measurement value for the thermoelectric voltage after the formation of the spot weld.

Abstract: A method and an apparatus for ascertaining an evaluation time interval for assessing the quality of a spot weld based on a course of a temperature at the weld, call for a course of a variable which is unequivocally associated with the temperature to be ascertained for a multiplicity of reference spot welds of differing quality, and for the courses of the variable to be compared with each other. A time interval which is determined from the comparison of the courses is used as the evaluation time interval, and the courses are significantly different from each other and have a sequence which corresponds to a sequence of the qualities of the associated reference spot welds. An allocation of the quality of any spot weld can be carried out simply and precisely by using values of the temperature-dependent variable within the evaluation time interval.

Abstract: The temperature is determined at a spot weld. The spot weld is between parts to be welded to one another. The parts are formed of a first metal and the spot weld is made with an electrode of a second metal placed in contact with the parts. The thermoelectric voltage between parts and the electrode is measured and the temperature is determined from the thermoelectric voltage measured in the measuring step. A device for determining the temperature includes a voltmeter connected between the parts to be welded and the electrode. The temperture determination is utilized in assessing the quality of spot-welded joints in automated manufacture, for example in the automobile industry.

Abstract: A method for the preparation of a mixture of at least one reactive element or an alloy thereof and a liquid metal melt, including introducing the reactive element or alloy thereof, in a liquid state and under pressure, within, i.e. below the surface of, the metal melt, is provided. An apparatus to facilitate the method above is also provided. The apparatus includes a crucible, an immersion pipe that passes into the crucible, an accommodating vessel for storing the reactive element or alloy thereof and a pressure unit.

Abstract: Multi-layer compensator with spacers arranged between the layers and with the spacers having the shape of flat strips distributed parallel to the longitudinal axis of the compensator over the circumference, with a gap between spacers.

Abstract: A method for monitoring structures by measuring electrical quantities including subjecting an electrically conducting component to an a-c current with a predetermined frequency in a given direction generating a magnetic flux in a given direction, tapping a voltage drop across two measurement points mutually spaced apart by a given distance at individual partial regions of the component with two measuring lines contacting the component, forming a first conductor loop from the measuring lines and the component with an inductively effective area being as small as possible, forming a second conductor loop being substantially parallel to the given direction of the current and perpendicular to the given direction of the magnetic flux, tapping an induction voltage from the change of the magnetic flux as close as possible to the measuring points with the second conductor loop, feeding the voltage drop and the induction voltage to an electronic evaluation circuit, and deriving the local resistance of the component at