As is known, reactions that result in the oxidation of carbon and form a large volume of carbon monoxide take place in the reaction zone of converters when the bath is blown with oxygen. The pulsating nature of gas evolution in this case generates a spherical longitudinal wave that propagates in the bath and the lining and results in vibration of the converter. Theoretical and experimental studies show that the level of vibration is determined by the dynamics of oscillatory" phenomena occurring during evolution of the gas. The level of vibration is related to the kinetics of decarbonization taking place in the secondary reaction zones of the furnace [1]. Thus, vibration level may serve as an indirect indicator of the rate of oxidation of carbon in the converter bath. This idea was the foundation for a system developed by the State Metallurgical Academy of the Ukraine for vibration monitoring of deearbonization and prediction of carbon content at the end of the blow. The system has successfully completed commercial trials in 60-ton converters at the Dnepropetrovsk plant. Figure t presents a dia~am showing the location of the main elements of the system. A vibration pickup, preamplifier, and function converter are mounted on the undriven trunnion of the converter. An electric signal proportional to the rate of decarbonization is sent along a cable from the function converter to the control panel of the furnace. The following is located on the control panel: main (logic) block: recording unit, to record the curve of the resulting vibration signal; illuminated signal panel, to predict carbon content at the end of the blow. Figure 2 shows the character of change in the level of vibration in a typical heat. As on other converters [2], on the whole the change in vibration level reflects generally accepted representations on the dynamics of decarbonization in the converter bath. Vibration level is lowest in period I, when iron, silicon, and manganese oxidation reactions take place and almost no carbon is oxidized. An increase in temperature is accompanied by "ignition" of the melt, and both vibration level and carbon oxidation rate increase (period [I). The vibration level in period III indicates that the development of the decarbonization process has reached a maximum. The level of vibration and the rate of carbon oxidation decrease at carbon contents below 0.25-0,35 % (period W). A characteristic feature of steelmaking in the 60-ton converters at the plant is the raising and lowering of the lance in the second half of the blow. In this case, the strength of the vibration signal changes in accordance with known laws governing the effect of lance position on decarbonization processes. Raising the lance reduces the degree of assknilation of oxygen during the oxidation of carbon and decreases decarbonization rate and signal strength. Lowering the lance increases the assimilation of oxygen by the converter bath and intensifies the oxidation of carbon, which is accompanied by an increase in the strength of the vibration signal. The easily detected reduction in the strength of the vibration signal at the end of the blow was used to predict the carbon content of the bath and stop the blow at the proper time toward the end of the heat. The reduction in decarbonization rate and the corresponding reduction in signal strength at the end of the blow occurred at a certain carbon content in the bath. For example, a 14-20% reduction in vibration level relative to the maximum value corresponded to a concentration of 0200.25% C in the bath. A carbon concentration on the order of 0.1,1-0.18% was predicted when vibration level decreased 2030%. A reduction in vibrations by more than 40% corresponded to a carbon concentration below 0.1% in the bath.