Based on over 50 years of experience in thermogravimetry, NETZSCH has developed the thermobalance TG 209 F1 Libra®. This instrument allows for analyses to be carried out even faster, more accurately, and across an extended temperature range.
Twice as Fast by Means of BeFlat®
In contrast with other thermobalances, no time-consuming baseline determinations need normally to be carried out with the TG 209 F1 Libra® prior to a measurement. The unique BeFlat® function of the Libra automatically compensates for any external factors influencing the measurement. This cuts work hours by up to 50%, leaving more time available, for example, for further measurements.
20 Times Faster Due to High Heating Rates
The heart of the TG 209 F1 Libra® is the micro furnace made of high-performance ceramics. It not only allows for a wider sample temperature range of up to 1100°C, but also for heating rates of up to 200 K/min. The user can thus receive the results of the analysis – even at highest temperature – within a few minutes, i.e. 20 times faster than for other thermobalances.
More Comprehensive and Faster Characterization by Patented c-DTA®
With the TG 209 F1 Libra®, the sample temperature is measured directly. Endo- and exothermal reactions can now be detected and show, for example, the melting point of the sample, in the evaluation. This yields considerably more information on the sample behavior without having to carry out further measurements.
High-Performance Ceramics for a Long Lifespan
The lifespan of the new, especially designed ceramic furnace – even when investigating materials containing corrosive components – is many times longer than that of conventional thermobalances. The analysis of fluorinated or chlorinated polymers is therefore no problem. The reaction and purge gases flow in the material, vertical direction. Condensation on measure-relevant components (sample holders) can therefore be excluded. This not only is gentle on the material, but also prevents occurrence of the dreaded memory effect which can distort subsequent measurements in conventional systems.
QMS 403 DAëolos®
The TG 209 F1 Libra® can be coupled to the Quadrupole Mass Spectrometer QMS 403 DAëolos® and/or to an FT-IR Spectrometer or to aGC-MS. Gases released are conducted via a heated fused silica capillary or transfer line directly into the gas analyzer, where the volatile fragments can be detected down to the ppm-range during the decomposition of the sample.
Key Technical Data

- Temperature range: RT to 1100°C at the sample
- Max. furnace temperature: >1100°C
- Heating and cooling rates: 0.001 K/min to 200 K/min
- Cooling time: 12 min (1100°C to 100°C)
- Wide measuring range: 2000 mg
- Resolution: 0.1 µg
- Sample crucible volume: up to 350 µl
- Atmospheres: inert, oxidizing, reducing, static, dynamic
- Vacuum-tight assembly: up to 10-2 mbar (1 Pa)
Clay Bricks
Clay bricks are articles that are produced at a commercial scale and hence, the costs have to be kept to a minimum. Therefore, only locally available clays are
employed. The mineral content of the raw materials can be mixtures of fireclays, illites, montmorillonite, chlorite, quartz etc. After forming and drying, the raw brick is fired in kilns up to 1000°C to its final consistence. Often additives are also included like sawdust or polystyrene to increase the porosity of clay bricks. The pollution of brick production can be very high dependent on the raw material used. Not only the emission of CO 2, CO , NOx, but also the emission of HF and SO2 has to be considered and limited by primary solutions (optimization of the firing process, additives etc.) or secondary procedures (dust filter, fluorine filter etc.).
Instrumentation and Test Conditions
The instrument used was the TG 209 F1– QMS 403 Aëolos®. The test conditions are listed below:
|
|
Temperature range |
RT ... 1000°C |
Heating rates |
10 K/min |
Atmosphere |
Air at 40 ml/min |
Sample mass |
21.7 mg |
Crucible |
Alumina |
Sensor |
TG type Platinel |
Results
Small amounts of fluorine are often present in clay materials that are used in brick production. Using mass spectrometer or FTIR to detect HF or fluorine is difficult, because these mixtures are present only in trace amounts.

Fluorine has mass number 19 and HF mass number 20. These mass numbers occur when large quantities of water are released due to the formation of the oxygen isotope 18 (H218O +, 20amu) and H3O+ (19amu). The measured brick clay shows the evolvement of fluorine at about 380°C and 800°C (peak temperatures) indicted by mass number 19 and no correspondend high intensity of mass number 18 representing water.
20 03 2013 netzsch libra ton EN