Many processes take place at particularly high temperatures, for example in the case of pyrolysis or catalysis and biomass gasification. In this context, the highly accurate weighing of material samples under corresponding measurement conditions is of great scientific interest. Against this background, Rubolab offers a highly accurate measuring instrument for performing thermogravimetric analyses (TGA), based on the unique technology of a Magnetic Suspension Balance.
RuboSORP TGA instrument uses the Magnetic Suspension Balance Technology. This allows high resolution mass determination under high pressure and high temperature conditions by utilizing resistant measurement cells. A scientific microbalance is located outside of the cell. Thanks to contactless magnetic suspension coupling, mass changes within the pressurized and heated measurement cell can be determined. When collecting a measurement, the sample whose mass change is being measured is attached to the permanent magnet. The actual position is then detected and controlled via a high performance PID controller. In order to establish a free levitation position for the permanent magnet and measurement object, voltage is applied to the electromagnet outside of the measurement cell. This allows the sample mass to be measured under contact free extreme conditions. Load decoupling allows taring or calibrating of corresponding measurement signal. When this decoupling occurs, only the permanent magnet remains in levitation position (zero-point position). Taring in zero-point position ensures long term stable and drift-compensated measurements. When measuring point is selected, the measurement object is lifted, and the corresponding weight is detected by the microbalance.
The RuboSORP TGA systems are available in 8 different versions which can be used in different pressure and temperature ranges. All Magnetic Suspension Balances have an accuracy of 10 µg. A higher resolution of 1 µg is available on request. The standard sample crucible of TGA unit can be filled with max. 20 g of sample material. Special sample crucibles for carrying out measurements on forced-flow bulk materials or flowed-through liquids are also available.
Apart from the standard versions, customized solutions are available on request!
Forced-Flow Through Sample Materials
Best possible agreement of measurement data with real processes thanks to improved sample crucible concepts
The RuboSORP TGA can be equipped with forced-flow sample crucibles in order to reproduce processes as realistically as possible. Moreover, an improved mass transfer between the fluid atmosphere and the sample material reduces the required measuring time considerably.
Intelligent Software including Uncertainty Calculation
RuboSORP TGA instrument will be delivered with a powerful software package. With the help of this software all measuring parameters can be read, monitored and changed continuously. In addition to an integrated measurement data evaluation, a DIN ISO EN 9001 compliant uncertainty analysis of the obtained measurement data is carried out.
Pyrolyse, Reaction Rate of Cellulose
The picture on the left shows the temperature-dependent reaction rate [g/g*s] of cellulose measured in an inert atmosphere (blue) and in the presence of carbon dioxide (green). The results show that the reaction starts at much lower temperatures due to the presence of CO2.
Gasification of Graphite at Different Pressures
The picture shows the mass loss [g] recorded on a graphite sample as a function of temperature, measured at three different pressures. All three graphs show a significant weight loss at a temperature above 800°C, indicating that gasification of the material is occurring.