TOM_air is a ThermoOptical Measurement system (TOM) for components and samples with a maximum size of about 30 mm and is operated in air. It has a telecentric beam path for precise dimensional measurement. Dimensional changes are detected optically with a resolution of 0.1 µm. The user defines which measurements are to be tracked via measurement windows. Numerous measurement windows can be set simultaneously. The test setup in a MoSi2 heated chamber furnace is very flexible and allows the study of various phenomena. Thus wetting properties of melts can be measured as well as the sintering kinetics of green bodies and the warpage during co-firing. Using additional modules numerous other measurements are available: creep rates, changes in weight, viscosity, acoustic emission, etc. The latter is used for the detection of cracking during heat treatment. It is used for the optimization of the debinding conditions. Measurements are defined by job files and carried out fully automatically - including the computer control of the furnace atmosphere.