For determining the Vicat softening temperature and the heat deflection temperature under load on plastics and thermoplastics, available with 3 or 6 testing stations. Test specimens are charged with a constant load and immersed in a bath, where the temperature is increased at a standard velocity. The attained heat resistance rate of plastic material is a widely required parameter for product characterization, for quality control and for evaluating the conformity to the previewed applications.