ABSTRACT
Thermogravimetry (TG or TGA – thermogravimetric analysis) is a method in which the mass of the substance to analyze is measured as a function of its temperature, the change of which is planned. The apparatus of thermogravimetry provide thermogravimetric curves. They are diagrams mass of the sample (in ordinates) as a function of the temperature T. The curve is constituted of plateaus when the mass of the sample is constant. The apparatus of thermogravimetry comprises an analytical balance, a furnace, a device for the introduction or for the purge of the atmosphere of the system and a computer for the control of the apparatus and the treatment of data. The measurement of the sample temperature is often carried out with the help of a thermocouple. Thermogravimetry is used for the recognition of the processes which are shown by a loss of mass of the sample. This can be the volatilization of some impurities, the transformation of the sample and even the degradation of the studied compound.
