Abstract: Systems and methods monitor the activity of carbon in a heat treating atmosphere, e.g., where a two phase region is desired for spherodize annealing. The systems and methods generate a computed activity of carbon value for the gas atmosphere as a function of temperature, partial pressure of oxygen, and carbon monoxide content of the gas atmosphere, and without determining a carbon dioxide content of the gas atmosphere. The systems and methods can make use of the computed activity of carbon value, e.g., to control the gas atmosphere.

Abstract: A method and apparatus is disclosed to improve the metal yield by adjusting the tilt angle of a tilting vessel having a submerged tap hole. The tilt angle is adjusted in response to parameters inherent in the pouring process, i.e. the proximity of the vessel contents to the vessel lip, the age of the tap hole, the liquid head over the tap hole, etc. Additionally, methods are disclosed to enhance the metal yield by advancing or moving back the furnace without knowledge of the tilt angle. Moreover, such methods and apparatus can be implemented through the use of computer based algorithms. The methods can also be used to archive pouring parameter information for future uses such as training and reviewing.

Abstract: A dross processing system has a motor mounted to a motor support arm by a motor support carriage, and has a carriage guide which engages the motor support carriage to guide the motor along a vertical path between a raised position and a lowered position. The motor is moved by a motor height actuator connected between the motor support arm and the motor support carriage. A hood having a hood rim and a hood upper structure is configured to be engaged by the motor support carriage when moved to the raised position. When the motor is moved to the lowered position, the hood rim engages a reaction vessel upper rim. The motor support arm can rotate between a loading/dumping position and an operating position. The dross processing system can be partially automated by a microprocessor. A preferred impeller for agitating dross and a plug setting tool can be employed.

Abstract: A metal alloy, such as steel, is manufactured in an electric arc furnace system equipped with at least one sensor, at least one a controller including a logic program and a variable valve in fluid communication with the furnace and a material source. The nature and quality of the slag formed over a molten metal during manufacture of steel is dynamically controlled by continuously adjusting the addition of one or more material to the arc furnace through the variable valve.

Abstract: An apparatus and method for measuring the level of a free surface of molten metal in an electromagnetic continuous casting process using an AC electromagnetic field. A detection coil is provided to detect the sum of a magnetic field applied from an induction coil and an induced magnetic field based on eddy current in the molten metal. An arithmetic unit is provided to detect the surface level of the molten metal by removing a variation of the applied magnetic field with a variation in current to the induction coil from an output signal from the detection coil. The surface level of the molten metal can be accurately measured by determining whether a variation in the output of the detection coil results from a variation in the applied magnetic field or a variation in the surface level of the molten metal.

Abstract: The invention provides a carburization treatment method in which a carburization treatment is conducted simultaneously with an operation of supplying a hydrocarbon gas and an oxidative gas into a furnace kept under a reduced pressure. Preferably, the internal pressure within the furnace is kept at 0.1 to 101 kPa, the hydrocarbon gas is one, two or more than two kinds of gases selected from the group consisting of C3H8, C3H6, C4H10, C2H2, C2H4/C2H6 and CH4, while the oxidative gas is an air, an O2 gas, or CO2 gas.

Abstract: An introduced-air-flow-rate SA is determined by adding an adjusted value A given from an oxygen density controlling system to a required-air-reference-flow-rate RA demanded by the charging amount of pellets The introduced-air-flow-rate is controlled where the required-air-reference-flow-rate RA is the feed forward value Thus, it the charging amount of the pellet is varied, since the introduced-air-flow-rate SA is determined by the adjusted value A and the required-air-reference-flow-rate RA varied in response thereto, the control response can be quickened without decrease of the stability.

Abstract: A holding furnace, particularly for a die-casting apparatus, comprising a bucket which can be heated, is adapted to contain molten material and is provided with a lid which can be opened and is shaped substantially like an inverted cup; the lid is provided with at least one opening for introducing protective gas having a higher relative density than air and adapted to generate an atmosphere for protection from contact with air for the molten material at regions that are free from the containment means walls of the bucket.

Abstract: A method for producing a molten iron in a blast furnace comprises the steps of: preparing an optical fiber covered with a metallic tube; measuring a temperature of the molten iron flow discharged from a tap hole of the blast furnace by means of making use of a metallic tube covered by the optical fiber to obtain an information of the temperature of the molten iron; and controlling a heat conditions of the blast furnace, based on the obtained information of the temperature of the molten iron. Controlling a heat conditions is achieved by using a heat conditions estimation model, and by inferring a level and a transition of the heat conditions in the furnace.

Abstract: A process for stirring molten steel in a container. In this process, argon gas is introduced into the container at a flow rate of from about 0.005 to about 0.2 cubic feet of argon per ton of molten steel per minute, the extent to which said container is caused to vibrate is measured, analog signals are produced corresponding to the rate of flow of argon gas into said container, the analog signals are sampled at a rate of at least 800 times per second, the analog signals are converted to digital signals, the digital signals are transformed by subjecting them to fast Fourier transformation, and the transformed digital signals are evaluated.

Abstract: An apparatus and method for reclaiming contaminated scrap metal, more particularly an improved reverberatory furnace designed for melting scrap. The amount of hydrocarbons volatilized from the melting of contaminated scrap is measured and the fumes are passed into the main hearth for burning. As the amount of fuel value contained within the fumes increases, the amount of fuel provided to the burner is proportionally reduced while the amount of oxygen is kept constant. This will ensure that the amount of fuel and the amount of oxygen present within the furnace is completely burned without excessive free oxygen or unburned fuel building up within the furnace or furnace exhaust. The burner will be operating under lean fuel conditions or under fuel rich conditions such that the flame temperature is lower than at stoichiometric firing, whereby the burners create reduced NOx.

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: An improved molten metal feed system is provided for high speed, continuous casting of metals and alloys. The feed system includes a distributor box having an insulative lining which supports an internal flow distributor board. The flow distributor board includes a plurality of openings of various sizes and shapes spaced apart along the width of the board. The presence of the flow distributor board effectively separates the box into lower and upper sections and restricts the flow of liquid metal through the board and thus, forces entering liquid metal to fill the entire width of the distributor box below the flow distributor board. In addition, the liquid metal is stabilized across the width of the distributor box resulting in a balanced temperature gradient. Once the lower section of the distributor box is filled, the metal flows through the openings in the board into the upper section of the distributor box and into the feed tip nozzle.

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: 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: An on-line system for measuring the composition of scrap metal, including a loader with a load sensor having a motion compensator linked to a bulk material analyzer such as a prompt gamma-ray neutron activation analyzer. The grade of scrap used to prepare batches for a melt is controlled to provide a batch having desired properties and composition.

Abstract: A mold for sampling molten metals includes a cavity body for receiving a measured sample of a molten metal, and, an insert containing a material for promoting carbide formation in the molten metal as it cools, the insert containing a measured amount of the material in finely divided solid form. The insert may be adhered to a recess in the mold surface or within a fill inlet passage and is preferably in the form of an enclosed tube formed of thin-walled material which contains the carbide formation promoting material in finely divided solid form. The insert may be formed of a metal closed at one end by a plastic adhesive material which opens upon immersion to release a stream of the carbide formation promoting material into the fill opening of the mold.

Abstract: Process for the preparation of a heat treatment atmosphere by a catalytic reaction in a catalytic reactor including an inlet and an outlet between a first gas mixture comprising oxygen and a second gas mixture comprising a hydrocarbon for the purpose of supplying said atmosphere to a user site comprising at least one user location, comprising the steps of:a) feeding said first and second gas mixture at a given flowrate into the inlet of said catalytic reactor;b) continuously measuring the pressure of the heat treatment atmosphere obtained at the reactor outlet;c) comparing the pressure measured during step b) with a setpoint pressure level P.sub.

Abstract: The proposed method of carrying out diagnostics on a process for the thermo-chemical treatment of steels and alloys in a glow discharge involves monitoring the ionization characteristics of the atmosphere as revealed by the intensity of the electromagnetic radiation in various frequency intervals. The proposed device for carrying out the method in question comprises a primary converter (1) in the form of an electromagnetic radiation emitter unit and contains filtering elements (5) mounted in such a way that they can be positioned in the radiation zone in front of the receiver (6) on a rotating disk (4). The disk (4) is provided with a rotation drive (7) for positioning the elements (5).

Abstract: A device for sampling flue gas from a duct includes a casing tube having a longitudinal axis, and a port for connecting an interior of the casing tube with a source of cooling fluid, an extraction tube having an end part disposed in the interior of the casing tube, an end of the extraction tube extending through the casing tube to form an inlet opening, an intermediate tube disposed between the casing tube and the extraction tube and spaced from the casing tube and the extraction tube to define a cooling fluid circuit and a sampling tube extending in an interior of the extraction tube and having an opening in an interior of the extraction tube.

Abstract: Equipment for bringing ingots of thixotropic metal alloy to the semisolid or semiliquid state including a heat chamber for holding the solid ingots introduced at ambient temperature, and a source generating air currents within the chamber to heat the ingots principally by convection, and a unit for controlling the temperature of the ingots. The ingots are supported and conveyed through a circular path internally of the heat chamber by a set of radial platforms revolving between an infeed zone and an outfeed zone.

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: Apparatus for the production of iron carbide in a shaft furnace, by reacting a carbon containing reducing gas as the process gas with particulate metal oxide material for an extended residence time at low temperature, including residence time and operating temperature controls. The resulting iron carbide product is also disclosed.

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.

Abstract: Method and apparatus for recovering free aluminum from a metal bearing dross containing free aluminum metal and oxides of the metal. Hot dross is collected from a hot dross source into a vessel, and the vessel is placed into a sealable storage container. The storage container is insulated to maintain heat generated by the hot dross within the interior of the storage container to maintain the dross at or near its temperature when first placed in the storage container. An inert gas is then introduced into the container to purge the container of all gasses other than the inert gas. The inert gas reduces thermiting of the hot dross and limits the cooling of the hot dross in order to maintain the hot dross at an elevated temperature while the hot dross remains in the storage container. The dross is then removed from the vessel and introduced dross into a dross processing device such as a furnace.

Abstract: The disclosure is of apparatus for determining the transformation characteristics of a metal alloy by treating the alloy to render it austenitic and then monitoring the isothermal decomposition of the austenite by measuring the magnetic change in the alloy.

Abstract: A treating fluid is in contact with a negative electrode containing lithium of a lithium cell under a first condition to react a surface portion of the negative electrode, and a treating fluid is in contact with lithium existing inside an article formed on the surface of the above-described negative electrode under a second condition. The cells can be effectively treated under safety condition to collect either the valuable substances, or the cell constructive components.

Abstract: Apparatus and method for obtaining accurate sonic input data from a metallurgical furnace, for accomplishing accurate control of a lance injecting oxygen and/or other substances into the melt. A remotely located hydrophone is placed in sonic communication with a liquid circuit cooling the lance. Sound levels and frequencies are picked up through the liquid, and transmitted to a programmable logic controller which generates control signals operating the lance. An associated real time analyzer compares the sonic signature of the input data to predetermined sonic signature data retained in memory, and adjusts lance operation through the programmable logic controller accordingly in order to operate the furnace optimally. Sonic transmission is more accurate, and the hydrophone is more protected from the harsh furnace environment due to its remote location and employment of liquid sound transmission, when compared to other microphone arrangements.

Abstract: A method for heat treating a metal component uses a first heating system having a first high intensity heating portion to rapidly heat the component to a desired temperature and a second heating portion to maintain the component temperature for solution heat treatment. The heating system is an indexing-type system which includes a plurality of individual heating stations to effect solution heat treatment of the component. Following quenching, a second heating system having a first high intensity heating portion to rapidly heat the component to a desired temperature and a second heating portion to maintain the component temperature artificially ages the component.

Abstract: Disclosed herein is a method of sequentially and continuously determining the concentrations of carbon, hydrogen, and nitrogen in molten steel using a single apparatus. Disclosed also herein are a method and an apparatus for determining trace amounts of carbon in molten steel which are the specialized application of the principle used for the above-mentioned method.

Abstract: A video photometric color sensing system is provided for characterizing the color of a homogeneous substance on a real time basis. The sensing system includes a sample port for holding a homogeneous substance and a camera quantifies a color video image of the homogeneous substance and provides as outputs analog voltage signals representative of the amount of red, green and blue in the color video image. A peak detector circuit receives the analog voltage signals representative of the amount of red, green and blue in the color video image and generates peak red, green and blue analog voltage signals and uses these individual voltage values of each component to derive the luminance value from software generated nonadditive matrix.

Abstract: This invention relates to a method to provide a system for solid material arging into vertical reactors by electronic control of the exhaust gases, a unique process applied for charging into vertical reactors, cupolas, ferrous and non-ferrous blast furnaces, and shaft furnaces in the absence of the use of conventional flap valves, pressure chambers, doors or bells to prevent the exhaust gases from escaping uncontrolled to the atmosphere. In this invention, the solid charging materials are loaded at all times into the reactor through the charge duct without loss of exhaust to the atmosphere or air infiltration into the exhaust gases. A controlled post combustion is conducted when the exhaust gases contain substantial amount of combustible gases. An adjustable-high-temperature-air blast is used for reduced fuel costs. The heat of exhaust gases is transferred to the air and the waste gases are exhausted at low temperature.

Abstract: A flame sensor of the present invention for use in a gas cutting apparatus is capable of directly measuring an electrical current flowing through a flame formed between the torch and the workpiece and includes a first terminal coupled to the torch; a second terminal coupled to the workpiece; and a sensing portion for detecting a current between the first and the second terminals, and generating a current sense signal.

Abstract: For quenching heated metallic work pieces with a quenching intensity that lies in the region of H values from 0.2 to 4, which is typical for oil or water quenching, a cooling gas is used as the quenching medium in the form of discrete jet streams issuing from a nozzle field and impinging on the work piece surface to be cooled. With limiting of the blower power for the cooling gas serving a predetermined maximum limit of about 1000 kW per square meter of nozzle field the quenching intensity, with suitable selection of gas jet parameters, in particular the gas velocity w, the gas pressure p, the gas jet cross-section and the number of impinging jets per unit of surface is brought to an H value between 0.2 and 4.

Abstract: Method and apparatus is disclosed for heat treating coiled, metal strip in bell shaped annealing furnaces employing an annealing stand upon which coils of strip are vertically stacked. An inner cover removably sealed to the stand surrounds the coil and an outer cover surrounds the inner cover. A vacuum is drawn within the inner cover while the work is being preheated to volatize oil on the coil into hydrocarbon vapors and permit the hydrocarbons to be drawn off prior to annealing so that carbon soot formation does not occur. A unique concentric, two seal arrangement is disclosed which provides for drawing a vacuum between the seals to positively seal the inner cover to the base while providing a fail safe mechanism for monitoring the process thus permitting a potentially explosive reducing atmosphere, such as pure hydrogen, to be used in the annealing furnace in a safe manner.

Abstract: An installation for heat treatment or thermochemical treatment of steel permit instantaneous and permanent checking of the concentration of carbon at the surface of the steel, particularly in the course of the carbon enrichment of the surface zone of a workpiece. The process provides for the circulation in contact with this surface zone of a gaseous flux permitting the saturation concentration of carbon at the surface to be obtained at maximum speed, and for regulating this flux as a function of time. The installation comprises a monitored-atmosphere furnace having an input and an outlet for a gaseous flux, feed means forming this gaseous flux, and means for regulating the gaseous flux; it is equipped with data-storage and/or calculating means, and the feed means are designed to form a gaseous flux suitable for obtaining a saturation concentration of carbon at the surface of the workpieces in less than one minute.

Abstract: The tubular rod (7) for sampling, mounted in a duct for the evacuation of fumes for example from a heat treatment or a melting furnace, includes an extractor tube (8) extending in a closed sleeve (9) comprising an inlet (11) and an outlet (12) of cooling fluid, the extractor tube having an end part opening outside the sleeve by means of an opening (10) for sampling fumes and a connecting part (14) extending outside the sleeve for connection to a circuit of analysis including a suction pump. The opening (10) is advantageously directed in counter-current with respect to the direction of circulation (F) of the fumes (11). Application such as for process control in an electrical furnace for the production of steel with injection of oxygenated gas.

Abstract: A method for producing a cast aluminum vehicle wheel uses a high intensity electric infrared heating system to heat treat the wheel. The infrared heating system is an indexing-type system which includes a plurality of individual heating stations. A first group of heating stations effects solution heat treating of the wheel, while a second group effects artificial aging. The infrared system enables the solution heat treating and aging to be completed in less than 15 minutes.

Abstract: A method for producing a cast aluminum vehicle wheel uses a high intensity electric infrared heating system to heat treat the wheel. The infrared heating system is an indexing-type system which includes a plurality of individual heating stations. A first group of heating stations effects solution heat treating of the wheel, while a second group effects artificial aging. The infrared system enables the solution heat treating and aging to be completed in less than 15 minutes.

Abstract: Apparatus and process are disclosed for providing, and continuously monitoring and controlling, a tapered temperature profile in solid metal first heated to a specified initial temperature. Temperatures are monitored at a plurality of locations along the length of the metal and are adjusted by successively withdrawing and returning a portion to a heating source through physical movementIn one aspect, apparatus and process continuously monitor and control a tapered temperature profile in a billet of aluminum alloy through a first step of rapid heating in a single-zone electric induction furnace to a temperature sufficient to bring the billet to its cold end set point while not exceeding its maximum skin temperature. The temperatures of the billet are monitored at its die end and its ram end and are adjusted by successively withdrawing and returning the billet to the induction furnace to reduce the heat in the ram end relative to the die end.

Abstract: A method for heat treating an aluminum part is provided. The method includes heat treating the aluminum alloy part with direct radiation from a source of infrared energy until the part attains a desired state of heat treatment. The method and apparatus further include monitoring of the part and controlling the intensity of the radiation source through proportional control in response to the measured temperature.

Abstract: Apparatus for producing a metal powder includes a cooled hearth structure in which a metallic alloy is melted and a heat source above the hearth positioned to heat the melt in the hearth. The cooling of the hearth causes a protective hearth skull to form between the melt and the hearth itself. The hearth is placed within an environmental control chamber. A supply structure provides a continuous supply of the metallic alloy to the hearth structure from the exterior of the chamber. A metal powder producer is positioned to receive molten metal from the hearth, and a continuous stream of the molten alloy from the hearth is transferred to the metal powder producer. The transfer is accomplished by tipping the hearth or by teeming through an opening in the bottom of the hearth. The hearth structure can utilize two individual hearths, controllably arranged so that molten metal is drawn from one hearth while the other is recharged.

Abstract: In the continuous carburization furnace in which the temperature of the heaters can be controlled individually at every carburization processing position; carburization reference data at each carburization processing position is read; a temperature and carbon potential at each position at least during carburization and diffusion processes is detected; a carburized quantity of the processed member at each position is calculated with reference to the detected temperature and carbon potential; a carburization history is calculated by integrating the carburized quantity at each position of the carburization processed member, and a carburizing condition at a next carburization processing position is determined depending on a difference between the carburization history at the time of terminating the carburization process at each position of the carburization processed member and the carburization reference data at each position.

Abstract: The present invention includes process and apparatus for continuously monitoring or detecting a liquid element or compound in another, different liquid including introducing a gas into a first liquid, measuring bubble size of bubble formation of the gas in the first liquid, introducing a second liquid element or compound into the first liquid to form a combination liquid, introducing a gas into the combination liquid, measuring bubble size of bubble formation of the gas in the combination liquid, and comparing gas bubble formation in the first liquid with gas bubble formation in the combination liquid to determine the amount of the second liquid in the combination liquid. The present invention further includes controlling or adjusting the amount of the second liquid contained in the first liquid in response to the monitoring and detecting determination of the present invention.

Abstract: This method of preheating scrap iron mixed with plastic, rubber and resinous, i.e. organic, materials and intended for electric furnaces, in particular electric arc furnaces, is characterized by transforming the plastic, rubbery or resinous and like materials or organic nature present in the scrap iron, to advantageously eliminate them by a path able to produce thermal energy usable for preheating the scrap to be melted, said path consisting of pyrolysis in an environment fed both with the the scrap to be melted and with said organic materials, the whole being previously shredded.

Abstract: A process and an arrangement are disclosed for the removal of a low-melting embedding body from a higher-melting embedded component. A groove is provided along a molding-in base of the component and by means of the widening of the groove via heatable elements, the resulting halves of the embedding body are removed. The process and the arrangement are particularly suitable for separating embedded guide and moving blades from the manufactured embedding body.

Abstract: A shaft furnace for melting copper solid into copper melt has been controlled by manual operation with reference to the actual storage quantity of the holding furnace so far. The burner air pressure of each zone of the shaft furnace is controlled by the actual storage quantity and the time change of it using Fuzzy Logic. The temperature of copper melt is adopted as another input signal. The proportion of burner air pressure of the zones is revised by the melt temperature. Automatic control basing upon the present invention decreases the fluctuation of storage quantity of the holding furnace.

Abstract: A continuous annealing line for annealing a cold-rolled strip of a ultra-low-carbon steel comprising a heating furnace for heating the strip which is fed continuously, with or without a soaking furnace following the heating furnace, a cooling furnace in which the heated steel strip is cooled, and a carburizing/nitriding furnace disposed between the heating furnace or the soaking furnace and the cooling furnace. The carburizing/nitriding furnace may be divided into a plurality of zones, each of which is provided with control means for controlling the carburizing/nitriding atmosphere and carburizing/nitriding temperature in the zone. The continuous annealing line may further comprise a plurality of carburizing/nitriding furnaces and have an arrangement for conducting a switching between a mode in which the carburizing/nitriding furnace is used for carburizing/nitriding the steel strip and a mode in which the carburizing/cooling furnace is used for cooling the steel strip.

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.