2 Mettler Toledo, CH-8603 Schwerzenbach

Today, most thermoanalytical measurements are performed with predefined constant heating rates. Despite the great success and wide application of this method, it has been known for forty years that concepts such as thermal effects of a sample exist which must be enlisted in the determination of the experimental conditions, i.e. particularly how the heating rate can be adapted during the analysis.

In the determination of the conditions for a conventional thermal analysis, the user is forced to decide between two different, frequently contradictory goals (experiment time or resolution). The selection of the heating rate is a determining factor: while the high heating rate leads to an amplification of an effect and to short experiment times, it can also result in an unsatisfactory separation of thermal events; a low heating rate allows the separation of thermal effects in close proximity, but leads to long experiment times.

Although modern instrument with a high sensitivity and a quick response furnace have reduced the time needed for an experiment, high resolution measurements always need a great deal of time.

A dynamic switching of the heating rate as available with MaxRes allows measurements with a clearly higher resolution during the same experiment time.

In the decision regarding whether a measurement should be performed with a constant or effect-dependent heating rate, the following points must be considered:

• Time available
• Simultaneous DTA measurement necessary or not?
• Is the mass change and/or the temperature of a particular event of interest?
• Repeat measurements necessary?

MaxRes allows measurement of samples with overlapping thermal effects with a higher resolution and within a considerably shorter time. Thanks to better separation, the evaluation and interpretation are easier and more dependable.