Abstract: An immersion measuring probe, particularly a drop-in measuring probe for metal melts, is provided having a measuring head, on which at least one sensor carrier having at least one sensor is arranged. The sensor carrier is held at or in an opening in the measuring head. At least a part of the measuring head is in electrical contact with a counter electrode of an electrochemical sensor arranged on the measuring head and forming a bath contact for the electrochemical sensor.

Abstract: An installation for non-destructive control for a metal tube in which an ultrasound sensor includes transducer elements that can be excited each at selected times. A downstream circuit for processing the sensed signals analyzes a global response of the tube at ultrasonic excitation. The transducer elements are only excited to produce a single emission and the downstream circuit recovers the samples of the sensed signals each through a transducer element, to associate therewith successive times respectively offset, to calculate plural global responses of the tube at a single emission, by modifying the shifts between the successive times.

Abstract: A fully automated system and method for rapidly and reliably detecting the ingestion of slag within the tip of a metal making lance. The system utilizes a temperature sensor disposed adjacent to the inner surface of the inner wall of a metal making lance tip. The sensor is in communication with a control station. The control station is preferably in operative communication with a valve for shutting off gas flow to the lance and, optionally, at least one alarm, a coolant fluid shut-off valve, and any other lance operation mechanisms as may be desired or necessary when slag is detected by the sensor. The inner wall of the lance tip is also preferably formed with a slag collecting reservoir for collecting ingested slag and directing it toward the temperature sensor for quick and reliable slag detection.

Abstract: A novel treatment method, for improving fatigue life, is provided that aims to resolve problems associated with conventional treatment methods for improving fatigue life of metal by reduction of stress concentration and conventional treatment methods for improving fatigue life of metal by introduction of compressive stress, that is, problems of poor efficiency in work execution, required level of skill of workers, and the impossibility of quality control due to lack of means for measuring the effect after treatment, characterized in that, for locations in metal for which fatigue is a problem, after pre-treatment is performed, ultrasonic impact treatment is performed, and thereafter, a quality assurance test is performed so as to improve the fatigue life of the metal.

Abstract: This invention relates to a method and apparatus for improved process control in combustion applications, and particularly those relating to the steelmaking industry. An apparatus is provided for process control in a combustion application comprising a laser to transmit a near-infrared laser beam through off-gas produced by the combustion application, a detector to detect the transmitted laser beam and convert the detected laser beam to an electrical signal, and a control system for providing adjustment of select inputs to the combustion application in response to the electrical signal from the detector. The method of this invention comprises transmitting a near-infrared laser beam through off-gas produced by the combustion application, detecting the transmitted laser beam, and adjusting select inputs of the combustion application in response to the detected transmitted laser beam.

Abstract: A system for determining process parameters for the ladle refinement of steel includes a computer executing a number of software algorithms for determining one or more process parameters for various steel refinement process steps. In one embodiment, for example, the computer is configured to determine the total amount of flux additions to achieve a desired sulfur percentage as part of a steel desulfurization process. In another embodiment, the computer is configured to determine the total quantity of oxygen to be injected into the steel as part of a steel reoxidation process. In still another embodiment, the computer is configured to determine a melting temperature of inclusions within the refined steel, and to determine whether this melting temperature is within an acceptable range to successfully process the steel in a continuous steel strip casting apparatus/process, or whether the steel must be reworked to achieve an acceptable inclusion melting temperature.

Abstract: A device (10) for continuous measurement of the temperature of molten metal in a furnace or recipient for its production and treatment comprises a heat analysis instrument (14) placed in a lance (12) which blows inert gas and/or high-pressure compressed air against a surface of metal slag (18) of a furnace or recipient (20).

Abstract: Cracking of a crucible can cause heavy damage to the system in melting furnaces. A reliable monitoring of threatening breaking out of the melt is therefore needed. For this purpose a monitoring device for melting furnaces is provided to monitor the breaking out of melt and includes a closed circuit consisting of several conductor sections with at least a partially conducting surface and a measuring/displaying device. A first conductor section is series connected through an ohmic resistor R to a second conductor section. The first conductor section is arranged directly adjacent, however, electrically isolatingly spaced from and with respect to the second conductor section.

Abstract: A device is provided for measuring temperature in molten metals with an optical fiber. The optical fiber is connected directly or indirectly to a measurement instrument and is held by a carrier. The immersion end of the fiber is fed through a body that can be consumed in the metal melt. The consumable body exhibits a consumption rate of at most 10 cm/min, and the consumption rate is approximately equal to or greater than the rate at which the structure of the optical fiber is destroyed.

Abstract: A system for determining process parameters for the ladle refinement of steel includes a computer executing a number of software algorithms for determining one or more process parameters for various steel refinement process steps. In one embodiment, for example, the computer is configured to determine the total amount of flux additions to achieve a desired sulfur percentage as part of a steel desulfurization process. In another embodiment, the computer is configured to determine the total quantity of oxygen to be injected into the steel as part of a steel reoxidation process. In still another embodiment, the computer is configured to determine a melting temperature of inclusions within the refined steel, and to determine whether this melting temperature is within an acceptable range to successfully process the steel in a continuous steel strip casting apparatus/process, or whether the steel must be reworked to achieve an acceptable inclusion melting temperature.

Abstract: The present invention is directed a method for adjusting the height of a lance with respect to a bath surface of any selected heat manufactured in a metallurgical vessel during a continuing series of heats.

Abstract: The present invention relates to systems of methods of detecting and measuring inclusions in liquid metals. More particularly, non-metallic inclusions having a conductivity level different from the liquid metal melt are forced to migrate and are collected on a measurement surface using electromagnetic Lorentz forces. The inclusions and their concentrations are detected at the measurement surface using either an electrostatic detection system or an optical detection system.

Abstract: An apparatus for rolling of a powder metallurgical metallic workpiece is provided having a feeding device, a first induction heating apparatus in operable communication with a first RF generator and at least a first hot rolling mill. A process control device monitors at least one parameter of the first RF generator and outputs a signal. A method for continuous rolling of a metallic workpiece is also provided using the apparatus for rolling. The process control device signal can be used to monitor metallurgical properties of the workpiece and provide in-line evaluation of the workpiece.

Abstract: This invention relates to a procedure for hardening the bearing surfaces (H1,H2,H3,H4) of a shaft or axle, in particular a crankshaft (2) or camshaft, in which the bearing surfaces (H1-H4) to be hardened are hardened sequentially with the shaft or axle turning around their longitudinal axis (L) by means of a heating and quenching device (3), in which the distortion of the shaft or axle that arises in the area of the respective bearing surface (H1) during the course of hardening is determined, in which the shaft or axle is supported by at least one supporting device (9) during hardening of a bearing surface (H1-H6), which is placed against a previously hardened bearing surface (H1), and in which the setting of the supporting device (9) is regulated taking into account the distortion determined for the bearing surface (H1), against which the supporting device (9) is placed, and a device which enables hardening of crankshafts with a minimal distortion.

Abstract: The invention relates to a method for controlling the decarburization of steel components in a furnace during heat treating processes. The concentration of CO2 and/or CO in the furnace is monitored in a first batch in order to determine periods of elevated CO2/CO concentrations, and inert gas is injected in subsequent batches during the previously determined periods of elevated CO2/CO concentrations.

Abstract: A method and apparatus for quality control of laser shock processing. The method includes measuring emissions and characteristics of a workpiece when subjected to a pulse of coherent energy from a laser. These empirically measured emissions and characteristics of the workpiece are correlated to theoretical shock pressure, residual stress profile, or fatigue life of the workpiece. The apparatus may include a radiometer or acoustic detection device for measuring these characteristics.

Abstract: Method and apparatus for determining the cooling action of a flowing gas atmosphere on workpieces by a measuring body with at least on temperature sensor and heated to workpiece temperature and is exposed to the gas atmosphere. The method and apparatus are particularly useful in hardening steel.

Abstract: A sampler for melts, in particular for slag, includes a body having an inlet and a sample chamber with an inlet opening. The inlet opening is located in a chamber wall delimited by a first metal plate with an opening. Removal of a sample from the sample chamber is simplified by arranging a second metal plate flat against the first metal plate, with the second metal plate having an opening that, together with the opening of the first metal plate, forms the inlet opening.

Abstract: The present invention provides a pre-treatment apparatus for an analytical metal sample, the apparatus including (1) a treatment chamber having a sample charging port which can be opened and closed and provided at the top of the chamber, a sample discharging port which can be opened and closed and provided at the bottom of the chamber, and a gas inlet and gas outlet, (2) a sample carrying bar joined to a sample holder also used as a sputtering electrode, and provided to pass through at least one side wall of the treatment chamber so as to be substantially horizontally movable and axially rotatable, and (3) a sputtering counter electrode at least having portions arranged opposite to each other in a region not inhibiting the charge and discharge of an analytical metal sample so that the sample holder can be arranged in the counter electrode.

Abstract: A method for management of an anode furnace, from which an adjustable volume of flue gas is directed into a flue system, comprises the steps of measuring the actual flue gas temperatures in flues of each section as actual temperatures, taking related set temperatures from a set temperature schedule, calculating a time integral of deviation between actual and set temperatures, modifying the actual temperature during a baking process such that the time integral is reduced to zero at the end of the process, registering at least one of the oxygen content and the fuel load in each flue, and setting burner capacity according to the set temperature and to the available oxygen content in the flue.

Abstract: A multi-function lance for insertion into a vacuum degassing chamber, includes a top-blown oxygen lance provided as a path for gaseous oxygen. A nozzle is provided at a downstream end of the oxygen path used for blowing oxygen onto a molten metal. A water-cooled jacket surrounds the outer periphery of the top-blown oxygen lance. At least a set of paths for a fluid fuel and a gas for burning the fuel is positioned in a multi-function lance, namely in the water-cooled jacket, and a combustion burner is provided at a downstream end of the path. By using the multi-function lance according to the present invention, not only a safer and shorter preheating operation is enabled, but also oxygen lancing, temperature elevation of molten steel, and heating of the vacuum degassing apparatus itself are smoothly realized.

Abstract: An apparatus and method for indexing the slag-metal interface level in a metallurgical container uses an insulating refractory brick having a plurality of embedded conductor wires. Distal ends of the conductor wires are exposed at know, fixed distances from the distal end of the stick and flush with the brick face. The proximal ends of the conductor wires protrude a predetermined distance from the proximal end of the brick. The brick is attached to the inner lining of the container at a known distance from the floor of the container. The proximal wire ends are joined by a suitable connector to a signal-transmission cable containing a matching number of individual conductors, which is connected to a multi-channel voltmeter. Output from the multi-channel voltmeter can be input to a multiple-channel PC-based signal interpretation instrument. During operation the voltage output of each sensor circuit is continuously monitored.

Abstract: A method for producing a metal strip which reduces the risk of the strip breaking over the course of a path, the strip being conveyed under stress in the strip direction and in which, in an upstream feed path of the metal strip, defects in the edges of the strip are detected and then measures are taken to reduce the risk of these defects causing the strip to break, in which method the strip is provided, in the region of the detected defect, with at least one notch in the strip direction, at a distance which is further away from the edge of the strip than the maximum dimension of the defect transversely with respect to the strip direction.

Abstract: A device for direct observation of the charging process inside a shaft furnace during its operation, in particular a blast furnace, with a measuring lance, which is arranged above the charge column in the shaft furnace in such a way that it is exposed to the charge material falling from a charging device during the charging process, and sensor means which detect the position of the falling charge material in relation to the measuring lance.

Abstract: A method and apparatus for quality control of laser shock processing. The method includes measuring emissions and characteristics of a workpiece when subjected to a pulse of coherent energy from a laser. These empirically measured emissions and characteristics of the workpiece are correlated to theoretical shock pressure, residual stress profile, or fatigue life of the workpiece. The apparatus may include a radiometer or acoustic detection device for measuring these characteristics.

Abstract: A method is provided for improving the efficiency of a basic oxygen furnace operation and/or regulating its rate of molten iron consumption to accommodate interruptions in downstream production. The method comprises the steps of combining a wet scrubber sludge with hot slag to provide a slag/sludge mixture, commencing a steelmaking operation of the basic oxygen furnace (BOF), and introducing the slag/sludge mixture into the BOF during the steelmaking operation so that the BOF produces a desired quantity and quality of steel in a manner that is more efficient than without the slag/sludge mixture. Also provided is a system for improving the efficiency of a BOF operation. The system comprises a mixer and an introduction mechanism. The mixer is connected to a source of wet scrubber sludge and a source of hot slag. The mixer is adapted to combine the wet scrubber sludge with the hot slag to provide a slag/sludge mixture.

Abstract: A temperature measuring device comprises: an optical fiber; a metallic protective tube for covering the optical tube to form a metal-covered optical fiber; and a radiation thermometer connected to the metal-covered optical fiber. A heat insulation coating can be formed to cover the protective tube. A level measuring device comprises: an optical fiber; a metallic protective tube for covering the optical tube to form a metal-covered optical fiber; a radiation thermometer connected to the metal-covered optical fiber; transfer device for sending the metal-covered optical fiber to a surface of a molten metal to be measured and retracting to wind the metal-covered optical fiber from the surface; and level determination device for determining a level of the surface of the molten metal based on a temperature change detected by the radiation thermometer and an amount of feed of the optical fiber through the transfer device.

Abstract: A system and method for detecting molten slag in a tap stream between a steel making vessel such as a basic oxygen furnace (BOF) and corresponding ladle. An infrared (IR) imaging or detecting device(s) is used to image/view the BOF-to-ladle tap stream, the stream transmitting energy indicative of whether molten steel and/or slag is in the stream at a given time. Gray scale analysis is performed on pixels viewed from the tap stream to determine the number of steel pixels and the number of slag pixels in the stream at a given time. When the ratio or percentage of slag pixels exceeds a predetermined value or amount, an alarm may be actuated to cause an operator to tilt the converter upward to stop tapping, or the converter may be automatically tilted upward to stop tapping.

Abstract: The present invention refers to a method for determination and control of the amount of nitrogen dissolved in metallic liquid phases and to a device permitting, when placed in the steel producing plant and for instance in the tundish or in the continuous casting mold, the determination of nitrogen content directly from the liquid phase. Such a device can point out possible nitrogen pick-up in real-time, thus permitting to immediately intervene.

Abstract: In a method for determining electromagnetic waves originating from the interior of a melt (3), in particular a metal melt, a gas-filled hollow space (26) is formed within the melt (3) by blowing in gas and electromagnetic waves emitting from the melt (3) are observed through the blown-in gas and evaluated by feeding the electromagnetic waves via an optical system (20) to a detector (22) for determining the temperature and/or chemical composition.

Abstract: A method of and an apparatus for the production of steel utilizing a single vessel for the electric arc smelting of scrap, directly reduced iron or pig iron in solid form, and for the oxygen blowing of the resulting melt through an oxygen lance introduced via a tower-shaped part of the roof. Another part of the roof can pivot to allow charging of the furnace with solids and the tower can be provided with a funnel enabling a molten iron charge to be fed to the furnace.

Abstract: A system and method for detecting molten slag in a tap stream between a steel making basic oxygen furnace (BOF) and corresponding ladle. BOFs are used in the manufacture of steel. An infrared (IR) imaging or detecting device is used to image/view the BOF-to-ladle tap stream, the steam transmitting energy indicative of whether molten steel and/or slag is in the stream at a given time. The imaging device uses mainly long IR wavelengths (e.g. wavelengths of from about 8 to 14 .mu.m) when imaging the molten tap stream, because these wavelengths are less susceptible to being blocked or absorbed by airborne gases and particles frequently found in BOF environments. In certain embodiments, all IR wavelengths other than those greater than about 8 .mu.m are filtered out and are not used to detect slag in the tap stream.

Abstract: A cupola emission control system is provided that includes both improved physical emission control equipment and improved controls for operating such equipment. The physical emission control improvements include an orifice ring of restricted diameter above the cupola main afterburners to improve the turbulence of the air in the upper cupola area to allow improved combustion of carbon monoxide. Further, twin venturis are provided with improved air passage control equipment to affect the temperature in the upper cupola combustion area. Further, an improved control system is provided whereby actual time calculations are made for remaining emission permitted amounts of certain pollutants, mainly carbon monoxide, and real time adjustments are made for cupola operation to assure compliance with such permitted emission limits.

Abstract: A flame detection system for detecting blockage in oil injection paths into blast furnaces utilized in the manufacture of iron. The flame detection system, as designed and installed, monitors the amount of light seen through a blowpipe peephole and causes an alarm to be actuated when a voltage falls below a predetermined threshold thereby indicating that the amount of light being received by a photocell mounted at the peephole is at a low enough level to possibly indicate injection path or port clogging. Efficient calibration circuitry and techniques are also provided.

Abstract: A method and apparatus for improving the yield of molten metal discharged from a metal production vessel limits the slag carryover by reducing turbulence of metal pouring through a discharge opening by inhibiting a vortex over the discharge opening, automatically sensing the presence of slag in the discharge opening, and terminating discharge through the opening in response to the detection of changing content through the discharged opening passage. Preferably, the inhibiting function includes inserting a slag reduction device, preferably a refractory body and maintaining the position of the device over the discharge nozzle. Preferably, the sensor is an electromagnetic coil that determines the change in content of the flow through the opening passage without direct contact with the contents of the opening. The combination of the slag vortex inhibitor and the flow content sensor is substantially improved metal pouring yield as demonstrated by actual slag reduction results.

Abstract: A temperature measuring device includes an optical fiber, a metallic protective tube covering the optical fiber, and a heat insulation coating covering the metallic protective tube such that the optical fiber is covered with the metallic protective tube and the heat insulation coating to form a double-covered optical fiber. The heat insulation coating contains carbon particles as an additive. In addition, a radiation thermometer is connected to the double-covered optical fiber, and a tip of the double-covered optical fiber forms a temperature measuring element for collecting and transmitting radiation to the radiation thermometer.

Abstract: A method and apparatus for improved control of continuous electric arc furnace steelmaking in which a charge velocity detector measures charge velocity of metallic charge introduced to the furnace. A charge mass detector measures a charge mass of metallic charge introduced to the furnace. A computer determines a feed rate based on the charge velocity and the charge mass. An automatic bath level probe detects a steel bath. The computer determines a steel bath level and optimal positions to insert a temperature probe and an oxygen lance, and further predicts new bath levels from one tapping time to the next tapping time. The temperature probe is inserted to an optimal measurement position based on the steel bath level and measures a steel bath temperature. The oxygen lance is positioned and maintained at an optimal oxygen injection position and injects oxygen into the bath.

Abstract: An apparatus and method for non-intrusive collection of off-gas data in a steelmaking furnace includes structure and steps for transmitting a laser beam through the off-gas produced by a steelmaking furnace, for controlling the transmitting to repeatedly scan the laser beam through a plurality of wavelengths in its tuning range, and for detecting the laser beam transmitted through the off-gas and converting the detected laser beam to an electrical signal. The electrical signal is processed to determine characteristics of the off-gas that are used to analyze and/or control the steelmaking process.

Abstract: A system and method for detecting molten slag in a tap stream between a steel making basic oxygen furnace (BOF) and corresponding ladle. BOFs are used in the manufacture of steel. An infrared (IR) imaging or detecting device is used to image/view the BOF-to-ladle tap stream, the steam transmitting energy indicative of whether molten steel and/or slag is in the stream at a given time. The imaging device uses mainly long IR wavelengths (e.g. wavelengths of from about 8 to 14 .mu.m) when imaging the molten tap stream, because these wavelengths are less susceptible to being blocked or absorbed by airborne gases and particles frequently found in BOF environments. In certain embodiments, all IR wavelengths other than those greater than about 8 .mu.m are filtered out and are not used to detect slag in the tap stream.

Abstract: An apparatus for the heat treatment of aluminum and aluminum alloy components in the aircraft manufacturing industry is precisely controlled in accordance with manufacturing regulations that must be satisfied if the components are to meet regulation quality standards for use in manufacturing an aircraft. For this purpose, the apparatus has a compact arrangement of four stations cooperating with a transport system that moves the components to be treated sequentially through the stations including an annealing station, a quenching station, a cleaning station, and a drying station arranged in that order in the transport direction. The transport system and the stations are controlled by a central processing unit for providing the required control signals, including closed loop controls and monitoring of all parameters that are necessary for a fault-free precisely repeatable heat treatment of the aluminum and aluminum alloy components.

Abstract: A method and apparatus for detecting and measuring suspended solid particles in a molten metal, even if the metal also contains liquid and/or gaseous inclusions. The method involves moving molten metal through an orifice of predetermined hydrodynamic diameter provided in an electrically non-conductive barrier. As the molten metal is moved through the orifice, a current path is established by passing a current through the orifice from electrodes positioned on opposite sides of the barrier. Changes in voltage of the current are measured as the metal is drawn through the orifice, and the number of particles suspended in said metal drawn through the orifice is detected from the voltage changes.

Abstract: A method for judging the properties of molten cast iron which consists of connecting three sampling vessels with an apparatus for obtaining a cooling curve of molten cast iron, measuring a cementite eutectic temperature (TEC) of cast iron poured to the first sampling vessel to which a chilling agent is contained, measuring a eutectic freezing temperature change of molten cast iron poured to the second sampling vessel being free of any additive, measuring a graphite eutectic temperature (TEG) of molten cast iron poured to the third sampling vessel, and inspecting a relation between the cementite eutectic temperature (TEC) and the graphite eutectic temperature (TEG) within the range of the eutectic freezing temperature change of molten cast iron.

Abstract: A molten metal inclusion sensor probe which is immersed in the molten metal and detects inclusions therein by the electric sensing zone method comprises inner and outer steel tubes disposed one within the other to form an annular gas containing space, the tubes being spaced apart from one another by electrically insulating spacing rings between the two tubes at or adjacent to the opposite ends thereof. The space is vented to the exterior of the outer tube, or in the case of a one-shot probe to the interior of the inner tube. A sensing zone member, which may also act to space the tube lower ends, is mounted by the tubes at their lower ends and provides the sensing zone orifice. In some embodiments the seals between the sensing zone member and the tube lower ends are maintained despite differences in expansion coefficients of the materials.

Abstract: A temperature measuring device includes an optical fiber; a metallic protective tube for covering the optical fiber to form a metal-covered optical fiber; and a radiation thermometer connected to the metal-covered optical fiber. A heat insulation coating may be added to cover the metallic protective tube.

Abstract: A method and apparatus for measuring a true temperature using a consumable optical fiber, wherein received light emitted from a high temperature liquid is divided into two light beams through a branching filter. A light of a first wave band from a first light beam of the two light beams is detected by a first radiation thermometer, and the light of the first wave band is converted into temperature to output a first temperature. A light of a second wave band from a second light beam of the two light beams is detected by a second radiation thermometer, and the light of the second wave band is converted into temperature to output a second temperature.

Abstract: There is provided a resin-silica sleeve or sheath for a sensor. The sheath has coating layer applied to its outer surface to improve the mechanical fracture strength and abrasion resistance of the sheath. The sheath, preferably, includes an inner layer or core and a non-reactive layer disposed about the inner layer, wherein the coating layer is disposed about the non-reactive layer.

Abstract: Apparatus and method for determining when the depth of molten (18) poured into a vessel (12) has reached a selected level. A conduit (22) connected to a source of pressurized gas and having an orifice (43) at its distal end (38) restricts the flow of gas out of the conduit which is positioned at a selected level in the vessel. A drop in pressure in the conduit (22) resulting from escape of compressed gas when the distal end (38) is melted by the rising molten metal is detected and signalled to a visible, audible indicator or directly to an electronic controller to discontinue pouring of metal (18) into the vessel (12).

Abstract: Both an apparatus and method for detecting slag in a flow of molten metal conducted through a ladle shroud are provided. In the apparatus, first and second conductive pins are mounted beside one another in a wall of the ladle shroud, the first being in contact with the flow of molten metal, but electrically insulated from both the wall and from the second conductive pin, the second being in electrical contact both with the wall and with the flow of molten metal. A voltmeter is connected between the two conductive pins for detecting differences in the electrical potential between them as molten metal flows through the shroud. Abrupt changes in potential caused by the passage of a metal slag interface through the shroud indicate the presence of slag in the molten metal.

Abstract: An improved thermocouple assembly suitable for measuring the temperature of molten metal, the thermocouple assembly having a sleeve comprised of a closed end suitable for immersing in the molten metal. The sleeve is fabricated from a composite material comprised of titanium alloy and having an outside surface to be exposed to the molten metal coated with a refractory resistant to attack by the molten metal; and a thermocouple located in the sleeve in heat transfer relationship therewith.

Abstract: Apparatus for determining in-blow % carbon content and/or the First Turn Down Carbon of a BOF heat includes a light sensor housed within a temperature regulated case having a sighting window including air wipe means to shield the light sensor from steelmaking dust and fume. The apparatus also includes a means to generate a signal that corresponds to the amount of oxygen blown into the BOF during a heat, and a programmable logic controller. The logic controller is programmed to continuously process oxygen blown signals from the signal generating means, and light intensity signals received from the light sensor. The program calculates continuous in-blow % carbon content of the heat based upon the difference in light intensity from a point of maximum light intensity emitted from the BOF vessel in relation to the amount of oxygen blown into the BOF vessel during the same period of time.