An oxide layer thickness measurement device according to the present invention stores, for each of layer thickness measurement sub-ranges constituting a layer thickness measurement range, layer thickness conversion information representing a correlation between a layer thickness and an emissivity where a ratio of a change in the emissivity to a change in the layer thickness in the layer thickness measurement sub-range falls within a set extent. Emitting light luminances of a surface of a steel sheet are measured at respective measurement wavelengths different from each other, and a temperature of the surface of the steel sheet is measured to thereby calculate the emissivity at each of the measurement wavelengths. Calculated in connection with the emissivity calculated at each of the measurement wavelength are the layer thickness corresponding to the emissivity at the measurement wavelength, and a ratio at the layer thickness by using the layer thickness conversion information corresponding to the measurement wavelength. The calculated thickness is extracted as a candidate value for an actual layer thickness when the calculated ratio is within the preset extent assigned for the layer thickness conversion information.

The invention relates to the use of an optical waveguide for optically measuring the temperature of a high-temperature melt, the optical waveguide directing electromagnetic waves from the measuring point to an optical detector and being moved to the measuring point with the aid of a fluid through a line through which the fluid flows. The optical waveguide has a core, cladding and a coating, with the coating consisting of a protective layer and an outer protective sheath. The outer protective sheath is firmly connected to the protective layer.

The invention relates to a device and method for measuring a temperature of a molten metal bath. The device according to the present invention comprises a cored wire and a detector. The cored wire comprises an optical fiber, a first metal tube, a filler layer of an organic material and a second metal tube accommodating the filler layer.

The invention concerns a method for feeding an optical cored wire into a molten metal bath and an immersion system and an immersion nozzle to carry out the method. The optical cored wire (6) is decoiled, a feeding and straightening device (4) with a plurality of rollers (20, 21) conducts feeding of the optical cored wire (6) in a feeding direction towards the metal bath (11) as well as a first straightening of the optical cored wire (6), and subsequently a separated further plurality of non-motor driven nozzle straighteners (13) arranged between the feeding and straightening device (4) and the metal bath (11) conducts a second straightening of the optical cored wire (6). Very high precision of temperature measurement can thereby be achieved.

The invention relates to an immersion device and a method for detecting a position of an optical cored wire using an immersion device. An immersion device for measuring a temperature of a metal melt inside an electric arc furnace vessel with an optical cored wire comprises a blowing lance for blowing purge gas into an entry point to the vessel and a detecting means for detecting a position of the optical cored wire. The optical cored wire can be moved in a feeding channel and/or in the blowing lance relative to the entry point. The detecting means is configured to detect the presence of the optical cored wire in or close to the blowing lance. This enables short distances between the leading end of the fiber and the melt and, thus, short time intervals between temperature measurement sequences.

Disclosed are a method and apparatus of estimating a depth of a molten pool formed during a 3D printing process, and a 3D printing system. A surface temperature of the molten pool is measure by taking a thermal image of a laminated printing object during the 3D printing process with a thermal imaging camera. The measured surface temperature is compared with a melting point of the base material to determine a surface boundary of the molten pool. The maximum lengths in x-axis and y-axis directions of a surface region of the molten pool defined by the surface boundary of the molten pool are determined as a length and a width of the surface of the molten pool, respectively. A maximum depth in the z-axis direction of the molten pool is determined in real time based on the length and width of the surface region of the molten pool.

An irradiating device for irradiating a machining field with a machining beam, in particular with a laser beam, for carrying out a welding process, is provided. The irradiating device includes a beam scanner for aligning the machining beam to a machining position in the machining field. The irradiating device has an imaging device for imaging a part-region of the machining field on a pyrometer which has at least two pyrometer segments. The imaging device images thermal radiation which emanates from the machining position in the machining field on a first pyrometer segment, and images thermal radiation which emanates from a position in the machining field being situated ahead of or behind the machining position along an advancing direction of the machining beam in the machining field on at least one second pyrometer segment. A machine tool having such an irradiating device is also provided.

One object of the present invention is to improve efficiency at the time of operation of a melting and refining furnace of a cold iron source using an oxygen burner lance, and the present invention provides a melting and refining furnace comprising a through-hole provided through a furnace wall, one or more oxygen burner lances provided in the through-hole: and a thermometer which is configured to measure a temperature in the furnace, the oxygen burner lance has one or more openings communicating with the inside of the furnace, and the thermometer is provided in any one of the openings.

The invention relates to the use of an optical waveguide for optically measuring the temperature of a high-temperature melt, the optical waveguide directing electromagnetic waves from the measuring point to an optical detector and being moved to the measuring point with the aid of a fluid through a line through which the fluid flows. The optical waveguide has a core, cladding and a coating, with the coating consisting of a protective layer and an outer protective sheath. The outer protective sheath is firmly connected to the protective layer.

Scanning Laser Epitaxy (SLE) is a layer-by-layer additive manufacturing process that allows for the fabrication of three-dimensional objects with specified microstructure through the controlled melting and re-solidification of a metal powders placed atop a base substrate. SLE can be used to repair single crystal (SX) turbine airfoils, for example, as well as the manufacture functionally graded turbine components. The SLE process is capable of creating equiaxed, directionally solidified, and SX structures. Real-time feedback control schemes based upon an offline model can be used both to create specified defect free microstructures and to improve the repeatability of the process. Control schemes can be used based upon temperature data feedback provided at high frame rate by a thermal imaging camera as well as a melt-pool viewing video microscope. A real-time control scheme can deliver the capability of creating engine ready net shape turbine components from raw powder material.