CONSTRUCTION OF AN EDUCATIONAL DEVICE FOR MEASURING THE COEFFICIENT OF LINEAR THERMAL EXPANSION OF METALS

U ovome radu kratko je opisano toplinsko širenje metala i prikazan je način računanja koeficijenta linearnog toplinskog širenja. Metodičkim pristupom definirani su zahtjevi ureĎaja, opisan je rad, te su ponuĎena rješenja parcijalnih funkcija ureĎaja. Na osnovu toga ponuĎene su 3 varijante ureĎaja za mjerenje koeficijenta linearnog toplinskog širenja metala. Sve 3 varijante su vrednovane prema tehničkim i ekonomskim kriterijima, te je odabrana najbolja varijanta. Za odabranu varijantu izvršen je odabir regulacije temperature, izbor materijala, te proračun. Temperatura će se regulirati pomoću PID regulatora. Izbor materijala izvršen je za toplinsku izolaciju unutar komore. Proračunati su gubici topline kako bi se dobila snaga električnog grijača. U nastavku je izvršena konstrukcijska razrada sastavni dijelova. Programom Autodesk Inventor izraĎeni su sklopni i radionički crteţi koji se nalaze u prilogu ovog rada.This paper briefly describes the thermal expansion of metals and shows how to calculate the coefficient of linear thermal expansion. Using a methodical approach, device requirements are defined, operation is described and solutions for partial device functions are offered. Based on this, 3 variants of devices for measuring the coefficient of linear thermal expansion of metals are offered. All 3 variants were evaluated according to technical and economic criteria, and the best variant was selected. For the chosen variant, the selection of temperature regulation, the choice of materials, and the calculation were made. The temperature will be regulated using a PID controller. The choice of material was made for thermal insulation inside the chamber. Heat losses were calculated to obtain the power of the electric heater. In the following, the structural elaboration of the constituent parts was carried out. The Autodesk Inventor program was used to create assembly and workshop drawings, which are attached to this paper