Method of inspecting powder-cored electrodes and device for effecting said method

Claim 1

A method of inspecting powder-cored electrodes, which are constituted by two components, namely casings filled with powder charges, comprising the steps of: introducing an electrode being inspected simultaneously into, and subjecting the same to, the combined effect of a high-frequency field and a magnetostatic field; changing the magnitude of the latter at least twice during the inspection; recording variations in the magnetic induction of the high-frequency field at the different magnitudes of the magnetostatic field, which variations are brought about by the introduction of the electrode in the field; then comparing the variations of the obtained records, one of the variations having been changed prior to introduction of the electrodes into the magnetizing fields to, thereby offset the influence of one of the two electrode components; and determining the weight of the other electrode component by the difference in the variations.

Claim 2

A method of inspecting powder-cored electrodes, which are constituted by two components, namely casings filled with powder charges, comprising the steps of: introducing an electrode being inspected simultaneously into, and subjecting the same to, the combined effect of a high-frequency field and a magnetostatic field; changing the magnitude of the latter at least twice during the inspection; recording variations in the magnetic induction of the high-frequency field at the different magnitudes of the magnetostatic field, which variations are brought about by the introduction of the electrode in the field; then comparing the variations of the obtained records, one of the variations having been changed prior to introduction of the electrodes into the magnetizing fields to, thereby offset the influence of one of the two electrode components; and determining the weight of the other electrode component by the difference in the variations.

Claim 5

A device for inspecting powder-cored electrodes, which are constituted by two components, namely casings filled with powder charges, comprising: a d.c. supply source with at least two outputs, providing direct currents of different values; a high-frequency generator producing a high-frequency alternating current; a magnetizing coil arranged coaxially with an electrode being inspected, for producing a magnetostatic field; a current coil also arranged coaxially with the electrode and with said magnetizing coil, and connected to said generator for producing a high-frequency magnetic field; a measuring coil also arranged coaxially with the electrode and with said magnetizing coil, and interacting with the high-frequency magnetic field of said current coil; measuring means connected to said measuring coil, and having an output, for measuring variations in the magnetic induction of the high-frequency magnetic field, caused by insertion of the electrode in said current coil; an amplifier with an input and two outputs, the former being connected to said output of the measuring means; two measuring channels connected for measuring signals at said outputs of the amplifier, said channels having respective inputs, the output signals appearing when the direct current from said source is applied to said magnetizing coil, and the high-frequency alternatinG current from said generator to said current coil; switching means connected between said magnetizing coil and said d.c. source, providing for the alternate connection of said magnetizing coil to said outputs of the d.c. source, causing the magnitude of the magnetostatic field to change; said switching means also being connected between said amplifier and said measuring channels, providing for switching synchronously with the alternate connection between said magnetizing coil and said d.c. source; said measuring channels being each provided with a peak detector having an output; which peak detectors, as a result of the synchronous switching, provide for measurement of the amplifier output signals proportional to the induction variations of the high-frequency magnetic field, caused by the insertion of the electrode in said current coil; one of said peak detectors providing measurement at one value of the magnetostatic field while the other peak detector provides measurement at another value of the same field; and an adder with inputs connected to said outputs of the peak detectors, providing for comparison of the amplifier output signals, one signal having been changed in a preset manner prior to the introduction of the electrodes into the coils, thereby excluding the influence of one of the two electrode components, and providing for a weight measurement of the other component.

Claim 6

A device for inspecting powder-cored electrodes, which are constituted by two components, namely casings filled with powder charges, comprising: a d.c. supply source with at least two outputs, providing direct currents of different values; a high-frequency generator producing a high-frequency alternating current; a magnetizing coil arranged coaxially with an electrode being inspected, for producing a magnetostatic field; a current coil also arranged coaxially with the electrode and with said magnetizing coil, and connected to said generator for producing a high-frequency magnetic field; a measuring coil also arranged coaxially with the electrode and with said magnetizing coil, and interacting with the high-frequency magnetic field of said current coil; measuring means connected to said measuring coil, and having an output, for measuring variations in the magnetic induction of the high-frequency magnetic field, caused by insertion of the electrode in said current coil; an amplifier with an input and two outputs, the former being connected to said output of the measuring means; two measuring channels connected for measuring signals at said outputs of the amplifier, said channels having respective inputs, the output signals appearing when the direct current from said source is applied to said magnetizing coil, and the high-frequency alternatinG current from said generator to said current coil; switching means connected between said magnetizing coil and said d.c. source, providing for the alternate connection of said magnetizing coil to said outputs of the d.c. source, causing the magnitude of the magnetostatic field to change; said switching means also being connected between said amplifier and said measuring channels, providing for switching synchronously with the alternate connection between said magnetizing coil and said d.c. source; said measuring channels being each provided with a peak detector having an output; which peak detectors, as a result of the synchronous switching, provide for measurement of the amplifier output signals proportional to the induction variations of the high-frequency magnetic field, caused by the insertion of the electrode in said current coil; one of said peak detectors providing measurement at one value of the magnetostatic field while the other peak detector provides measurement at another value of the same field; and an adder with inputs connected to said outputs of the peak detectors, providing for comparison of the amplifier output signals, one signal having been changed in a preset manner prior to the introduction of the electrodes into the coils, thereby excluding the influence of one of the two electrode components, and providing for a weight measurement of the other component.

Claim 8

A device for inspecting powder-cored electrodes, which are constituted by two components, namely casings filled with powder charges, comprising: a d.c. supply source; a high-frequency generator producing a high-frequency alternating current; a magnetizing coil powdered from said d.c. source and arranged coaxially with an electrode being inspected; current coils connected to said generator for setting up an alternating high-frequency magnetic field, and also arranged coaxially with the electrode; measuring coils respectively interacting with the high-frequency magnetic field, measuring means whose inputs are coupled to said measuring coils, providing for the measurement of changes in the magnetic induction of the high-frequency magnetic field, caused by the insertion of the electrode in said current coils; amplifiers whose inputs are connected to outputs of said measuring means; detectors connected to outputs of respective amplifiers; and an adder connected to outputs of said detectors, with a difference signal produced at the output of said adder, the signals being applied from said measuring coils, one signal having been changed in a preset manner prior to the introduction of the electrodes into the coils so that the influence of one of the two components of the electrode is minimal; as a result of which the weight of the other electrode component is obtained; said magnetizing coil having a variable diameter in sections of its winding, to set up a magnetic field whose intensity changes along the axis of said magnetizing coil, so that at least two sections are formed, featuring different intensities of the magnetostatic field, with said current and said measuring coils arranged in pairs within each of said sections.

Claim 9

A device for inspecting powder-cored electrodes, which are constituted by two components, namely casings filled with powder charges, comprising: a d.c. supply source; a high-frequency generator producing a high-frequency alternating current; a magnetizing coil powdered from said d.c. source and arranged coaxially with an electrode being inspected; current coils connected to said generator for setting up an alternating high-frequency magnetic field, and also arranged coaxially with the electrode; measuring coils respectively interacting with the high-frequency magnetic field, measuring means whose inputs are coupled to said measuring coils, providing for the measurement of changes in the magnetic induction of the high-frequency magnetic field, caused by the insertion of the electrode in said current coils; amplifiers whose inputs are connected to outputs of said measuring means; detectors connected to outputs of respective amplifiers; and an adder connected to outputs of said detectors, with a difference signal produced at the output of said adder, the signals being applied from said measuring coils, one signal having been changed in a preset manner prior to the introduction of the electrodes into the coils so that the influence of one of the two components of the electrode is minimal; as a result of which the weight of the other electrode component is obtained; said magnetizing coil having a variable diameter in sections of its winding, to set up a magnetic field whose intensity changes along the axis of said magnetizing coil, so that at least two sections are formed, featuring different intensities of the magnetostatic field, with said current and said measuring coils arranged in pairs within each of said sections.