The quality of products and their cost are interconnected. The common factor is the manufacturer's ability to measure parameters correctly during product production. Despite the progress of measurement systems, there are a number of specific quantities that, for various reasons, we cannot measure directly. For that reason, the so-called indirect methods or systems that allow parameters to be measured with the required accuracy are of interest. In this talk, we will present some proposals for indirect measurement systems and their implementation in real processes. One of them is the mathematical model for indirect measurement of the melt temperature in the oxygen converter. The main task of this model is continuously measuring (predicting) the temperature of the melt during the steel-making process in the converter. The change in the melt's temperature is calculated based on the heat balance. The temperature is increased by the heat released from the exothermic reactions of blown oxygen with melt components.

After Prof. Laciak’s talk, Marcela Pavlíčková, Assistant Professor at Kosice University, will give some information about Slovakia, the city of Kosice and Kosice Technical University, and will talk about quality tools, basic quality tools and new quality tools for measuring and evaluating quality.